JP7283443B2 - Rotating machine control device - Google Patents

Description

The present invention relates to a rotary machine control device.

2. Description of the Related Art Conventionally, there has been known a rotary machine control device that drives a polyphase rotary machine and a DC rotary machine with a single drive circuit.

For example, a motor control device disclosed in Patent Document 1 drives a three-phase AC motor and two DC motors by one three-phase inverter drive circuit. Specifically, this motor control device is used as a vehicle steering device, and drives a three-phase motor for electric power steering (EPS), a DC motor for tilting, and a DC motor for telescoping. This reduces the number of switching elements required to drive each motor.

Japanese Patent No. 5768999

In the prior art of Patent Document 1, after an ignition key is turned on, a tilt motor and a telescopic motor are operated in parallel to perform a position adjustment operation. Then, when it is determined that the position adjustment operation is not performed, the EPS three-phase motor is driven. In other words, either the DC motor or the three-phase motor is driven, and it is not assumed that the DC motor and the three-phase motor are driven at the same time. Also, due to the circuit configuration, it is not possible to simultaneously control the energization of the DC motor and the three-phase motor. In short, the prior art cannot drive even one DC motor and one three-phase motor at the same time. Furthermore, it is not possible to simultaneously drive a plurality of DC motors and a single three-phase motor.

Furthermore, when driving the DC motor, a switch for cutting off the energization of the phase to which the DC motor is connected among the phases of the three-phase motor, and the energization of the DC motor when driving the three-phase motor. A switch is required to shut off the For example, in the prior art of Patent Document 1, a configuration in which two DC motors are connected between three phases of a three-phase motor requires at least six switches.

SUMMARY OF THE INVENTION The present invention has been created in view of the above points, and an object thereof is to provide a rotary machine control device capable of simultaneously driving a polyphase rotary machine and a plurality of DC rotary machines.

The rotary machine control device of the present invention comprises one or more multiphase rotary machines (800) including one or more sets of multiphase winding sets (801), and at least one set of multiphase winding sets of one or more phases. It is possible to drive a plurality of DC rotating machines (710, 720, 730, 740) having a first terminal (T1), which is one end, connected to a phase current path of . The first terminals of any two or more DC rotating machines among the plurality of DC rotating machines are connected to the same single phase current path of the multiphase winding set. This rotary machine control device includes one or more multiphase power converters (601), DC rotary machine switches (MU1H/L, MU2H/L, MV3H/L, MV4H/L), and a controller (30). And prepare.

The multi-phase power converter is connected to the positive and negative poles of a power supply (Bt1) via a high potential line (BH1) and a low potential side line (BL1) respectively. The polyphase power converter converts the DC power of the power supply into polyphase AC power through the operation of a plurality of bridge-connected inverter switching elements (IU1H/L, IV1H/L, IW1H/L). A voltage is applied to each phase winding (811, 812, 813) of .

A switch for a DC rotary machine consists of a leg consisting of high-side and low-side switches connected in series via the DC motor terminals (M1, M2, M3, M4). A DC motor terminal is connected to a second terminal (T2), which is the opposite end of the DC rotating machine from the first terminal. The switch for the DC rotating machine makes the voltages (Vm1, Vm2, Vm3, Vm4) of the DC motor terminals variable by switching. The control unit operates the inverter switching elements and the switches for the DC rotary machine.

In one aspect of the present invention, the control unit turns on the low-potential-side DC rotary machine switch connected to the second terminal when energizing the DC rotary machine in the positive direction from the first terminal to the second terminal. Alternatively, the low potential side and high potential side DC rotating machine switches connected to the second terminal are switched so that the voltage of the second terminal is lower than the voltage of the first terminal, and the multiphase winding set Operation is performed to increase the neutral point voltage (Vn1). In addition, when energizing the DC rotating machine in the negative direction from the second terminal of the DC rotating machine to the first terminal, the control unit turns on the switch for the DC rotating machine on the high potential side connected to the second terminal, or The low-potential-side and high-potential-side DC rotating machine switches to be connected are switched so that the voltage of the second terminal is higher than the voltage of the first terminal, and the neutral point voltage of the multiphase winding set is lowered. to operate. The reference numerals in the claims correspond to the first to tenth embodiments in which two DC rotating machines are driven in one phase of one set of three-phase winding sets, or four DC rotating machines in total are driven in two phases. However, description of reference numerals corresponding only to other embodiments is omitted. In addition, regarding the reference numerals of the inverter switching element and the DC rotating machine switch, for example, "MU1H" and "MU1L" are collectively described as "MU1H/L".

The control unit of the present invention operates the switches for the DC rotary machine while operating the inverter switching elements to drive the multiphase rotary machine, and operates the switches connected to the same single phase of the multiphase winding set. A plurality of DC rotating machines can be driven simultaneously. Further, for example, in a configuration in which two DC rotating machines are connected to the same one-phase phase current path of a set of three-phase winding sets, a minimum of four DC rotating machine switches is required. Therefore, the number of switches can be reduced as compared with the prior art of Patent Document 1.

Supplementing the circuit configuration of the present invention, in a configuration including a plurality of multiphase power converters and a plurality of multiphase winding sets, the second terminal of the DC rotating machine is connected only to the switch for the DC rotating machine, and the first terminal is not directly connected to a polyphase winding set other than the polyphase winding set to which is connected. That is, the inverter switching element of a polyphase power converter different from the polyphase power converter to which the DC rotating machine is connected does not double as the DC rotating machine switch for that DC rotating machine. In short, the DC rotating machine switch is provided independently of the inverter switching element. With this configuration, by turning off the switch for the DC rotating machine, it is possible to stop only the energization to the DC rotating machine even when the inverter switching element is on.

The multiphase rotating machine is, for example, a rotating machine for steering assist torque output of an electric power steering system (901) or a reaction torque output of a steer-by-wire system (902).

The DC rotating machine includes a steering position system actuator that varies the steering position, specifically, a tilt actuator (720) and a telescopic actuator (730) of the steering column.

1 is a diagram of an EPS system to which an ECU (rotating machine control unit) of each embodiment is applied; FIG. 1 is a diagram of an SBW system to which an ECU (rotating machine control unit) of each embodiment is applied; FIG. Schematic diagrams for explaining (a) tilt operation, (b) telescopic operation, and (c) operation of a seat actuator. The figure which shows the connection structural example of a connector. FIG. 2 is a circuit configuration diagram of the first embodiment (three-phase motor x 1, DC motor x 2). The circuit block diagram of 2nd Embodiment (three-phase motor x1, DC motor x4). The circuit block diagram of 3rd Embodiment (with a three-phase motor relay and a DC motor relay). The circuit block diagram of 4th Embodiment (power supply relay individual, noise prevention element individual). The circuit block diagram of 5th Embodiment (power supply separate). FIG. 11 is a circuit configuration diagram of the sixth embodiment (individual power relays, common to negative direction power relays); The circuit block diagram of 7th Embodiment (power supply relay individual, negative direction power supply common). The circuit block diagram of 8th Embodiment (common to a power supply relay and a noise prevention element). The circuit block diagram of 9th Embodiment (DC motor relay common at the time of negative direction energization). FIG. 11 is a circuit configuration diagram of the tenth embodiment (common to DC motor relays when energized in the forward direction); FIG. 3 is a control block diagram of a three-phase control unit; Control block diagrams of (a) one example and (b) another example of a DC control unit. 4 is a flowchart showing the overall operation of an ECU; 4 is a flowchart of phase current calculation processing; Phase voltage and DC motor terminal voltage calculation processing <first and third patterns> - flowchart of branch number 1; Same as the above processing <first and second patterns> - branch number 2 (one side drive) flowchart. Same as the above process <second, fourth, fifth pattern> - flowchart of branch number 1; FIG. 10 is a flowchart of the same process <second pattern>—branch number 3 (simultaneous drive); A flowchart of the same process <third pattern> - branch number 2 (single drive). Same as the above processing <fourth pattern> - branch number 2 (single drive) flowchart. FIG. 10 is a flow chart of the same process <4th pattern>—branch number 3 (simultaneous drive); Schematic diagrams for explaining the concept of phase voltage and DC motor terminal voltage calculation processing for (a) first, second, and fifth patterns, (b) third pattern, and (b) fourth pattern. Waveform of the phase current flowing in the inverter. Waveforms of the phase currents energized in the three-phase winding set. Waveforms of (a) voltage command and (b) post-operation voltage command centered on VM in a configuration in which VH and VL are constant. Waveforms of the voltage command after neutral point voltage shift during (a) positive direction energization and (b) negative direction energization of the same. FIG. 3 is a control block diagram of a three-phase control unit in a configuration example in which VH and VL are variable; Waveforms of (a) voltage command and (b) post-operation voltage command centered on VM in a configuration in which VH and VL are variable. Waveforms of the voltage command after neutral point voltage shift during (a) positive direction energization and (b) negative direction energization of the same. Phase voltage, DC motor terminal voltage calculation processing <fifth pattern> - branch number 2 (one side drive) flowchart. FIG. 10 is a flowchart of the same process <5th pattern>—branch number 3 (simultaneous drive); The waveform of the post-neutral point voltage shift voltage command corresponding to the <fifth pattern>. 4 is a flowchart showing the operation immediately after the vehicle switch is turned on; FIG. 7 is a diagram showing current paths in S761 of FIG. 37 in the configuration of FIG. 6; 4 is a flowchart for switching between driving and stopping a DC motor while driving a three-phase motor; Flowchart of fail-safe threshold switching (example 1). Flowchart of fail-safe threshold switching (example 2). 4 is a time chart showing control example 1 for driving and stopping the DC motor during driving of the three-phase motor; 5 is a time chart showing control example 2 for driving and stopping the DC motor during driving of the three-phase motor; Axial sectional view of a two-system electromechanical integrated motor. FIG. 44 is a cross-sectional view along the XLV-XLV line. The schematic diagram which shows the structure of a three-phase double winding rotating machine. The circuit block diagram of 11th Embodiment (two systems, DC motor x 2 (one side)). The circuit block diagram of 12th Embodiment (two systems, two power supplies). The circuit block diagram of other embodiment.

A plurality of embodiments of a rotary machine control device will be described below with reference to the drawings. The rotating machine control device of each embodiment is applied to an electric power steering system (hereinafter "EPS system") or a steer-by-wire system (hereinafter "SBW system") of a vehicle, and functions as an EPS-ECU or SBW-ECU. In the following embodiments, EPS-ECU and SBW-ECU are collectively referred to as "ECU". Further, the first to twelfth embodiments will be collectively referred to as "this embodiment". In a plurality of embodiments, substantially the same configurations are denoted by the same reference numerals, and descriptions thereof are omitted.

[System configuration]
First, referring to FIGS. 1 to 3, a system configuration to which an ECU is applied as a "rotating machine control device" in this embodiment will be described. FIG. 1 shows an EPS system 901 in which a steering mechanism and a steering mechanism are mechanically connected. FIG. 2 shows an SBW system 902 in which the steering mechanism and steering mechanism are mechanically separated. 1 and 2, only one side of the tire 99 is illustrated, and the illustration of the tire on the opposite side is omitted.

As shown in FIG. 1, EPS system 901 includes steering wheel 91, steering shaft 92, intermediate shaft 95, rack 97, and the like. The steering shaft 92 is contained in the steering column 93, and has one end connected to the steering wheel 91 and the other end connected to the intermediate shaft 95. As shown in FIG.

A rack 97 is provided at the end of the intermediate shaft 95 on the side opposite to the steering wheel 91 to convert rotation into reciprocating motion and transmit it by means of a rack and pinion mechanism. As the rack 97 reciprocates, the tires 99 are steered via the tie rods 98 and knuckle arms 985 . Universal joints 961 and 962 are provided in the middle of the intermediate shaft 95 . This absorbs the displacement of the steering column 93 due to tilting and telescopic movements.

A torque sensor 94 is provided in the middle of the steering shaft 92 and detects the driver's steering torque Ts based on the torsional displacement of the torsion bar. In the EPS system, the ECU 10 controls driving of the three-phase motor 800 based on the steering torque Ts detected by the torque sensor 94 and the vehicle speed V detected by the vehicle speed sensor 14 to output a desired steering assist torque. Thus, in the EPS system 901, the rotating machine for steering assist torque output is used as a "polyphase rotating machine". Each signal to the ECU 10 is communicated using CAN, serial communication, or the like, or sent as an analog voltage signal.

In the second and twelfth embodiments, four DC motors 710 to 740 are provided as "DC rotating machines", and in the first, third to eleventh embodiments, two DC motors are provided as "DC rotating machines". DC motors 710, 720 are provided. Here, a configuration in which four DC motors 710 to 740 are provided will be described. The tilt actuator 710 and the telescopic actuator 720 are included in the “steering position system actuator” that varies the steering position, and are provided on the steering column 93 .

When the driver operates the tilt switch 12 to input an "up/down" instruction to the ECU 10, the ECU 10 instructs the tilt actuator 710 to perform a tilt operation. Then, as shown in FIG. 3A, the tilt actuator 710 adjusts the tilt angle and moves the steering wheel 91 up and down. When the vehicle switch 11 is turned on to start the vehicle, it moves to a driving position stored in advance, and when the vehicle switch 11 is turned off to stop the vehicle, it moves to the side where the driver's space is widened. The vehicle switch 11 corresponds to an ignition switch or a push switch of an engine vehicle, a hybrid vehicle, or an electric vehicle.

When the driver operates the telescopic switch 13 to input an instruction to "extend/retract" to the ECU 10, the ECU 10 instructs the telescopic actuator 720 to perform telescopic operation. Then, as shown in FIG. 3B, the telescopic actuator 720 adjusts the telescopic length and moves the steering wheel 91 back and forth. When the vehicle switch 11 is turned on to start the vehicle, it moves to a driving position stored in advance, and when the vehicle switch 11 is turned off to stop the vehicle, it moves to the side where the driver's space is widened.

Further, a first sheet motor 730 and a second sheet motor 740 are provided as sheet system actuators for moving each part of the sheet 17 . As shown in FIG. 3(c), the seat actuators include those that slide the cushion 171 forward and backward or in the height direction and recline the backrest 172. As shown in FIG. This specification does not specify which sheet motor moves which part in which direction. Any two types of DC motors may be selected as the first sheet motor 730 and the second sheet motor 740 among the motors of the respective parts of the seat.

Next, as shown in FIG. 2 , in the SBW system 902 in which the steering mechanism and the steering mechanism are mechanically separated, the intermediate shaft 95 does not exist with respect to the EPS system 901 . A steering torque Ts of the driver is electrically transmitted to the steering motor 890 via the ECU 10 . Rotation of the steering motor 890 is converted into reciprocating motion of the rack 97 , and the tire 99 is steered via the tie rod 98 and the knuckle arm 985 . Although not shown in FIG. 2, there is a steering motor ECU that drives the steering motor 890 in response to the driver's steering wheel input.

Also, the SBW system 902 does not allow the driver to directly sense reaction forces to the steering. Therefore, the ECU 10 controls the driving of the three-phase motor 800, rotates the steering wheel 91 so as to apply a reaction force to the steering, and gives the driver an appropriate steering feeling. Thus, in the SBW system 902, a rotating machine for reaction torque output is used as a "polyphase rotating machine".

In the SBW system 902 of FIG. 2, four DC motors 710-740 as "DC rotating machines" are used in the same way as in the EPS system 901 of FIG. In the following explanation of the control of the three-phase motor 800 and the DC motors 710 to 740 by the ECU 10, there is no difference between the EPS system 901 and the SBW system 902.

The DC motor type actuator used in the present embodiment may be a tilt, telescopic actuator, a seat actuator, a steering wheel storage actuator, a steering lock actuator, a steering vibration actuator, or the like. The steering lock actuator is provided near the steering wheel 91 and locks the steering wheel 91 so as not to rotate when the vehicle is parked. Based on the ON/OFF signal of the vehicle switch 11, the ECU 10 instructs the steering lock actuator to release or relock the steering lock.

In a vehicle equipped with the lane keep determination circuit 15, the lane keep flag F is generated when the lane keep determination circuit 15 determines that the vehicle has deviated from the lane or is likely to depart from the lane. When the lane keep flag F is input, the ECU 10 causes the steering vibration actuator to vibrate the steering wheel 91 to alert the driver. Note that the steering lock actuator may also function as the steering vibration actuator.

Regarding the configuration of the three-phase motor 800, a unit including the three-phase winding sets 801 and 802 and the configuration of the inverter or the like corresponding to the winding sets is called a "system". The first to tenth embodiments are single-system configurations, and the eleventh and twelfth embodiments are dual-system configurations in which each component is provided redundantly. Since the one-system motor structure is a commonly known technique, the description thereof will be omitted, and the two-system motor structure will be described later. At the end of the code or symbol of the two-system configuration, "1" is added to the configuration of the first system, and "2" is added to the configuration of the second system. In the one-system configuration, the codes and symbols of the first system in the two-system configuration are used. In the column of [Description of Codes], only typical codes corresponding to the first to tenth embodiments of the one-system configuration are described.

Next, with reference to FIG. 4, the connection configuration of the devices will be described. The three-phase motor 800 of this embodiment is configured as a "mechanical and electrical integrated motor" in which the ECU 10 is integrally configured on one side in the axial direction. On the other hand, the four DC motors 710-740 are connected to the ECU 10 via connectors, respectively. In other words, while the connection between the three-phase motor 800 and the ECU 10 is fixed, each of the DC motors 710 to 740 and the ECU 10 is configured to be connectable as an option according to needs, and the connector on the ECU 10 side Depending on the option, the circuit board may be common without being mounted.

FIG. 4 shows an example of connector connection configuration. In this configuration example, a power system connector 591, a signal system connector 592, and a torque sensor connector 593 are separately provided. A power line (PIG) from a DC power supply and a ground line are connected to the power system connector 591 . The signal system connector 592 is connected to a control power supply line (IG), a CAN communication line, and wiring of each of the DC motors 710 to 740 . The torque sensor connector 593 is connected with the power supply line, signal line, and ground line of the torque sensor 94 collectively.

Motor lines (M+, M−), position sensor power lines, position sensor signal lines, and ground lines are connected to the tilt actuator 710 and the telescopic actuator 720 . A configuration that does not use a position sensor by determining whether a predetermined position has been reached by torque or current and time, or by applying a constant current or voltage according to the on/off of the tilt switch 12 and telescopic switch 13. can also be FIG. 4 shows an example in which signals are received from the tilt switch 12 and the telescopic switch 13 by CAN communication. Since the wiring of the seat motors 730 and 740 is the same, illustration of each wire is omitted. If the motor does not require a position sensor, only the motor lines (M+, M-) are connected.

Although the motor wires (M+, M-) of the DC motors 710 to 740 are of the power system, they can be connected together with the signal system connector 592 because the motor current is smaller than that of the three-phase motor 800. If the current of the DC motors 710 to 740 is large, a separate connector may be used, or a connector common to the power system connector 591 for the power line (PIG) and ground line from the DC power supply may be used. Also, a separate connector may be provided for each of the DC motors 710-740.

[Circuit configuration for driving a single-system three-phase motor]
Next, configuration examples of the ECU 10 for driving the one-system three-phase motor 800 will be described as first to tenth embodiments with reference to circuit configuration diagrams of FIGS. The code for the ECU uses "10" in all the embodiments regardless of the difference in configuration. Of the elements shown in each figure, the ECU 10 is the part other than the three-phase winding set 801 of the three-phase motor 800 and the DC motors 710 to 740 .

The first embodiment is the basic configuration of the present invention, and drives one three-phase motor 800 and two DC motors 710 and 720 connected to the same single phase of the three-phase winding set 801. This is the minimum configuration for In the second embodiment, a total of four DC motors 710-740 are connected to each two phases of the three-phase winding set 801, corresponding to the system configuration of FIGS. 1-3. In the third and subsequent embodiments, applied configurations are added based on the configuration of the first embodiment.

(First embodiment)
FIG. 5 shows the overall configuration of the ECU 10 of the first embodiment. A three-phase winding set 801 of a three-phase motor 800 is configured by connecting U1-phase, V1-phase, and W1-phase windings 811, 812, and 813 at a neutral point N1. The voltage at the neutral point N1 is assumed to be a neutral point voltage Vn1. Note that the reference numeral "800" for the three-phase motor and the reference numerals "811, 812, 813" for the three-phase windings are shown only in FIG. 5 and omitted from FIGS. As shown in FIG. 46 relating to the description of the two-system configuration, which will be described later, each phase of the three-phase motor 800 generates a back electromotive force proportional to the product of the rotation speed and the sine value of the phase. The electrical angle θ of the three-phase motor 800 is detected by a rotation angle sensor.

The ECU 10 includes one inverter 601 as a "polyphase power converter," four DC motor switches MU1H, MU1L, MU2H, and MU2L as "DC rotary machine switches," and a control unit 30. The inverter 601 is connected to the positive electrode of the power source Bt1 via the high potential line BH1, and is connected to the negative electrode of the power source Bt1 via the low potential line BL1. The power source Bt1 is, for example, a battery with a reference voltage of 12 [V]. Also, the DC voltage input from the power supply Bt1 to the inverter 601 is referred to as "input voltage Vr1". A capacitor C1 is provided between the high potential line BH1 and the low potential line BL1 on the power source Bt1 side of the inverter 601 .

Inverter 601 converts the DC power of power source Bt1 into three-phase AC power by the operation of a plurality of bridge-connected inverter switching elements IU1H, IU1L, IV1H, IV1L, IW1H, and IW1L on the high and low potential sides. Inverter 601 applies a voltage to each phase winding 811 , 812 , 813 of three-phase winding set 801 .

Specifically, the inverter switching elements IU1H, IV1H, and IW1H are upper arm elements provided on the high potential side of the U1, V1, and W1 phases, respectively, and the inverter switching elements IU1L, IV1L, and IW1L are the U1, V1, and V1 phases, respectively. This is the lower arm element provided on the low potential side of the W1 phase. Hereinafter, the same-phase upper arm element and lower arm element are collectively referred to as "IU1H/L, IV1H/L, IW1H/L". Each switch used in this embodiment, including the inverter switching elements IU1H/L, IV1H/L, and IW1H/L, is, for example, a MOSFET. Each switch may be a field effect transistor, an IGBT, or the like other than a MOSFET.

Current sensors SAU1, SAV1, SAW1 for detecting phase currents Iu1, Iv1, Iw1 flowing through the respective phases are installed between the lower arm elements IU1L, IV1L, IW1L of each phase of the inverter 601 and the low potential line BL1. there is The current sensors SAU1, SAV1, and SAW1 are composed of shunt resistors, for example. For the phase currents Iu1, Iv1, and Iw1 flowing through the inverter 601, the phase currents supplied to the three-phase winding set 801 are denoted as Iu1#, Iv1#, and Iw1#. The relationship between both phase currents will be described later.

A DC motor switch as a "DC rotating machine switch" corresponding to the DC motor 710 is composed of a high potential side switch MU1H and a low potential side switch MU1L, which are connected in series via a DC motor terminal M1. be. Like the inverter switching elements, the high-potential-side and low-potential-side switches are collectively referred to as "MU1H/L" for DC motor switches. A DC motor switch corresponding to the DC motor 720 is composed of high potential side and low potential side switches MU2H/L connected in series via a DC motor terminal M2. The DC motor switches MU1H/L and MU2H/L other than those of the fifth embodiment are provided between the high potential line BH1 and the low potential line BL1 in parallel with the inverter 601 with respect to the power source Bt1 shared with the inverter 601. there is

A branch point Ju of the U1-phase current path of the three-phase winding set 801 is connected to a first terminal T1 that is one end of the DC motors 710 and 720 . The second terminals T2 of the DC motors 710 and 720 opposite to the first terminals T1 are connected to the DC motor terminals M1 and M2 of the DC motor switches MU1H/L and MU2H/L, respectively. . Therefore, the DC motor switch MU1H/L is connected to the DC motor 710, and the DC motor switch MU2H/L is connected to the U1 phase of the three-phase winding set 801 via the DC motor 720. FIG. The "U" in the DC motor switch codes "MU1H/L" and "MU2H/L" means the U1 phase, "1" is the first DC motor 710, and "2" is the second DC motor. 720.

In the DC motors 710 and 720, the direction of current flowing from the first terminal T1 to the second terminal T2 is defined as the positive direction, and the direction of current flowing from the second terminal T2 to the first terminal T1 is defined as the negative direction. A voltage Vx1 is applied between the first terminal T1 and the second terminal T2 of the DC motor 710, and a voltage Vx2 is applied between the first terminal T1 and the second terminal T2 of the DC motor 720. . DC motors 710 and 720 rotate forward when energized in the positive direction, and rotate in reverse when energized in the negative direction. For example, when the DC motor 710 is energized, a back electromotive force E1 is generated in proportion to the rotational speed ω1. In other words, if the constant of proportionality is E, the back electromotive force E1 is represented by the formula "E1=-Eω1". The symbols "T1, T2" of the first terminal and the second terminal are described only in FIG. 5, and are omitted in FIG. 6 and subsequent figures.

The DC motor switches MU1H/L and MU2H/L change the voltage Vm1 at the DC motor terminal M1 and the voltage Vm2 at the DC motor terminal M2 by switching such as duty control. Here, since the currents supplied to DC motors 710 and 720 are smaller than the phase currents flowing to three-phase motor 800, DC motor switches MU1H/L and MU2H/L are inverter switching elements IU1H/L and IV1H/L. , IW1H/L.

Supplementing the circuit configuration of the present embodiment, in a configuration including a plurality of inverters and a plurality of three-phase winding sets, the second terminal of the DC motor is connected only to the DC motor switch, and the first terminal is connected to the three-phase switch. It is not directly connected to a three-phase winding set that is separate from the phase winding set. In other words, the inverter switching element of the inverter other than the inverter to which the DC motor is connected does not double as the DC motor switch for that DC motor. In short, the DC motor switches are provided independently of the inverter switching elements. With this configuration, by turning off the DC motor switch, it is possible to stop only the energization to the DC motor even when the inverter switching element is on.

The control unit 30 acquires the electrical angle θ of the three-phase motor 800 and the three-phase currents Iu1, Iv1, and Iw1. Control unit 30 ^controls inverter switching ^elements IU1H/L ^{, IV1H} / L, IW1H/L and DC motor switches MU1H/L and MU2H/L are operated. The details of the control configuration of the control unit 30 will be described later with reference to FIGS. 15 and 16. FIG. Also, in the circuit configuration diagrams after FIG. 6, illustration of the control unit 30 and input signals is omitted.

(Second embodiment)
In the second embodiment shown in FIG. 6, a total of four DC motors 710 to 740 are connected to the U1 phase and V1 phase of the three-phase winding set 801 . Here, the names of the respective DC motors are described according to the system configuration of FIGS. 1 to 3. FIG. First terminals of the tilt actuator 710 and the telescopic actuator 720 are connected to the branch point Ju of the U1-phase current path of the three-phase winding set 801 . First terminals of the first sheet motor 730 and the second sheet motor 740 are connected to the branch point Jv of the V1-phase current path of the three-phase winding set 801 .

In the second embodiment, four sets of DC motor switches MU1H/L, MU2H/L, MV3H/L, and MV4H/L are provided corresponding to the four DC motors 710-740. In addition to the configuration of the first embodiment, the second terminal of the first sheet motor 730 is connected to the DC motor terminal M3 of the DC motor switch MV3H/L. A second terminal of the second sheet motor 740 is connected to the DC motor terminal M4 of the DC motor switch MV4H/L. Applied voltages Vx1 and Vx2 of DC motor relays 710 and 720 are collectively shown in the following diagrams. In addition, FIG. 6 collectively shows the applied voltages Vx3 and Vx4 of the DC motor relays 730 and 740 .

The "V" in the DC motor switch codes "MV3H/L" and "MV4H/L" means the V1 phase, "3" is the third DC motor 730, and "4" is the fourth DC motor. means 740. The DC motor switches MU1H/L, MU2H/L, MV3H/L, and MV4H/L change the voltages Vm1, Vm2, Vm3, and Vm4 of the DC motor terminals M1, M2, M3, and M4 by switching such as duty control. and

Hereinafter, one DC motor selected to be energized from among a plurality of DC motors, or two or more DC motors connected to the same single phase will be referred to as a "specific DC motor". The ECU 10 can energize the "specific DC motor" at the same time that the three-phase motor 800 is energized. DC currents supplied to the DC motors 710, 720, 730 and 740 selected as the specific DC motors are denoted as I1, I2, I3 and I4. The DC motors 710, 720, 730, 740 rotate forward or reverse depending on whether the DC currents I1, I2, I3, I4 are positive or negative. Also, when the specific DC motor is energized, a back electromotive voltage is generated in proportion to the number of revolutions. Back electromotive voltages generated in the respective DC motors 710, 720, 730 and 740 are denoted as E1, E2, E3 and E4.

(Modification of Second Embodiment)
In the second embodiment, in contrast to the first embodiment in which two DC motors 710 and 720 are connected to the U1 phase of the three-phase winding set 801, third and fourth DC motors 730 and 740 are further connected. It is connected to the V1 phase. In a modification, the third DC motor 730 may be connected to the V1 phase and the fourth DC motor 740 may be connected to the W1 phase. Alternatively, the third DC motor 730 may be further connected to the U1 phase, in which case the fourth DC motor 740 may be connected to any of the U1, V1, and W1 phases. Further, a form in which the third and subsequent DC motors are connected to the second system three-phase winding set 802 will be described later as a modification of the eleventh embodiment or a twelfth embodiment.

(Third embodiment)
Compared to the first embodiment, the third embodiment shown in FIG. 7 further includes three-phase motor relays MmU1, MmV1, MmW1 and DC motor relays MU1r, MU1R, MU2r, MU2R. Each motor relay is composed of a semiconductor switching element, a mechanical relay, or the like. In each embodiment shown in FIG. 7 and subsequent figures, each motor relay is composed of a MOSFET having a parasitic diode.

Three-phase motor relays MmU 1 , MmV 1 , and MmW 1 are provided in each phase current path between inverter 601 and three-phase winding set 801 . Specifically, in phase U1 to which DC motors 710 and 720 are connected, three-phase motor relays MmU1, MmV1, and MmW1 are provided on the three-phase motor 800 side of branch point Ju to DC motors 710 and 720 in the phase current path. ing.

For example, when energizing the three-phase motor 800, the control unit 30 turns on the three-phase motor relays MmU1, MmV1, and MmW1. On the other hand, when the three-phase motor 800 is not energized, the control unit 30 turns off the three-phase motor relays MmU1, MmV1, and MmW1. The three-phase motor relays MmU1, MmV1, and MmW1 can cut off the current from the three-phase motor 800 to the inverter 601, that is, the current due to the back electromotive force when turned off. Further, even if the inverter switching element IU1H is short-circuited, for example, the back electromotive force can cut off the current flowing from the three-phase motor 800 to the inverter 601 .

DC motor relays MU1r, MU1R, MU2r, and MU2R are provided closer to DC motors 710 and 720 than branch point Ju of the U1-phase current path. Here, the DC motor relays MU1r and MU2r that cut off the current in the positive direction when turned off are referred to as "positive DC motor relays", and the DC motor relays MU1R and MU2R that cut off the current in the negative direction when turned off are referred to as "negative direction relays." It is called a DC motor relay.

In the example of FIG. 7, the forward DC motor relays MU1r and MU2r are connected in series to the branch point Ju side, and the negative direction DC motor relays MU1R and MU2R are connected in series to the DC motors 710 and 720 so that the source terminals of the MOSFETs are adjacent to each other. be. The positive direction motor relay MU1r and the negative direction motor relay MU1R connected in series with the DC motor 710 are collectively referred to as "MU1r/R". Similarly, the sign of the positive and negative motor relays connected in series with the DC motor 720 is denoted as "MU2r/R".

In the third embodiment, in addition to DC motor switches MU1H/L and MU2H/L, DC motor relays MU1r/R and MU2r/R can be used to switch between energization and cutoff of DC motors 710 and 720. FIG. For example, even if the DC motor switch MU1H on the high potential side of the DC motor 710 is short-circuited, the DC motor 710 can be stopped safely by turning off the DC motor relay MU1r/R.

(power relay and anti-noise element)
The ECU 10 of fourth to tenth embodiments below further includes a power relay and a noise prevention element. The power supply relay is composed of a semiconductor switching element, a mechanical relay, or the like, and can cut off power supply from the power supply Bt1 to the load when the power supply is turned off. For example, if the power relay is composed of a MOSFET, current flows in one direction even when the parasitic diode is turned off, so it is necessary to distinguish in which direction the current can be cut off.

In this specification, the direction in which the current flows when the electrodes of the power source Bt1 are connected in the normal direction is called the forward direction, and the power relay that cuts off the current in the forward direction when turned off is called the "forward direction power relay". The direction in which the current flows when the electrodes of the power source Bt1 are connected in the opposite direction to the normal direction is called the negative direction, and the power relay that cuts off the current in the negative direction when turned off is called the “negative direction power relay”. A negative direction power relay is generally called a "reverse connection prevention relay" or a "reverse connection protection relay". ”.

The symbol of the positive direction power relay provided on the current path from the power source Bt1 to the inverter 601 is denoted by "P1r", and the symbol of the negative direction power relay is denoted by "P1R". In general, the positive direction power relay P1r is connected in series with the power source Bt1 side, and the negative direction power relay P1R is connected in series with the inverter 601 side. The positive direction power relay P1r and the negative direction power relay P1R connected in series are collectively referred to as "P1r/R". In addition, in the configuration in which another power relay is provided on the current path from the power source Bt1 to the DC motor switches MU1H/L and MU2H/L, the symbols of the separate positive power relay and negative power relay are respectively "Pdr", "PdR" and collectively "Pdr/R".

The anti-noise elements are coils and capacitors that function as noise filters. Reference numerals of the noise prevention elements provided at the input portion of the inverter 601 are denoted as "L1" and "C1". In addition, in the configuration in which another noise prevention element is provided at the input portion of the DC motor switches MU1H/L and MU2H/L, the reference numerals of the other noise prevention elements are described as "Ld" and "Cd".

(Fourth embodiment)
In the fourth embodiment shown in FIG. 8, power supply relays for both positive and negative directions, and coils and capacitors as noise prevention elements are individually provided for the inverter 601 and the DC motor switches MU1H/L and MU2H/L. . That is, a power relay P1r/R, a coil L1 and a capacitor C1 are provided between the power source Bt1 and the inverter 601 . A power relay Pdr/R, a coil Ld and a capacitor Cd are provided between the power source Bt1 and the DC motor switches MU1H/L and MU2H/L.

The power relay Pdr/R on the DC motor switch side cuts off the energization from the power source Bt1 to the DC motors 710 and 720, and the inverter side power relay P1r/R cuts off the energization from the power source Bt1 to the three-phase motor 800. do. Here, since the current supplied to the DC motors 710 and 720 is smaller than the phase current flowing to the three-phase motor 800, the power relay Pdr/R on the switch side for the DC motor is higher than the power relay P1r/R on the inverter side. A switch with a small current capacity is used.

(Fifth embodiment)
In the fifth embodiment shown in FIG. 9, the power supply connection configuration is different from that in the fourth embodiment. In the fifth embodiment, the inverter 601 and the DC motor switches MU1H/L and MU2H/L are connected to individual power supplies Bt1 and Btd. The DC voltage input from the power supply Btd to the DC motor switches MU1H/L and MU2H/L is referred to as "input voltage Vrd". The individual power sources Bt1 and Btd may be branched from the main common power source via separate wiring or fuses. A dashed line between the positive electrode of the power source Bt1 and the positive electrode of the power source Btd indicated by (*) marks in FIG. 9 indicates that the two power sources Bt1 and Btd are connected to the main common power source. With this configuration, it is possible to mutually suppress or isolate the effects of power supply noise, power supply voltage fluctuations, and the like.

(Sixth and seventh embodiments)
In the sixth and seventh embodiments shown in FIGS. 10 and 11, the forward power relay and the noise prevention element are connected to the inverter 601 and the DC motor switches MU1H/L and MU2H/L in the same manner as in the fourth embodiment. are provided separately. However, the negative direction power relay PR1 is provided in common to the inverter 601 and the DC motor switches MU1H/L and MU2H/L. The common negative direction power relay P1R is provided on the negative electrode side of the power source Bt1 in the sixth embodiment, and is provided on the positive electrode side of the power source Bt1 in the seventh embodiment. In this way, the positive direction power relays P1r, Pdr and the negative direction power relay P1R may be arranged differently.

(Eighth embodiment)
In the eighth embodiment shown in FIG. 12, in contrast to the fourth embodiment, a power supply relay P1r/R for both positive and negative directions, and a coil L1 and a capacitor C1 as noise prevention elements are connected to an inverter 601 and a DC motor switch MU1H/L. It is provided in common for MU2H/L. This configuration can reduce the number of elements.

(Ninth embodiment)
In the ninth embodiment shown in FIG. 13, instead of eliminating the negative direction DC motor relays MU1R and MU2R in the eighth embodiment, a common negative direction relay McomR is provided on the high potential line BH1. A common negative direction relay McomR can cut off the current flowing in the negative direction of DC motors 710 and 720 when turned off. This configuration can reduce the number of negative direction relays.

(Tenth embodiment)
In the tenth embodiment shown in FIG. 14, instead of eliminating the forward DC motor relays MU1r and MU2r in the ninth embodiment, a common forward relay Mcomr is provided on the low potential line BL1. A common forward relay Mcomr can interrupt the current flowing in the forward direction of the DC motors 710, 720 when off. This configuration can reduce the number of forward relays.

[ECU control configuration]
Next, the control configuration of the ECU 10 will be described. In the description of this part, the two DC motors 710 and 720 connected to the U1 phase are driven as the same one phase in the above embodiment, and the three-phase motor relays MmU1, MmV1, MmW1 and the DC motor relay Consider the third to eighth embodiments with MU1r/R, MU2r/R. Even if the phase to be connected is the V1 phase or the W1 phase, the symbols can be appropriately read and interpreted.

A detailed configuration of the control unit 30 will be described with reference to FIGS. 15 and 16. FIG. The control unit 30 includes a microcomputer, a drive circuit, and the like, and includes a CPU, ROM, RAM, and I/O (not shown), and a bus line connecting these components. The control unit 30 performs software processing by executing a program stored in advance in a substantial memory device such as a ROM (that is, a readable non-temporary tangible recording medium) by the CPU, or hardware processing by a dedicated electronic circuit. to perform control by

The control unit 30 controls the operation of inverter switching elements IU1H/L, IV1H/L, IW1H/L, DC motor switches MU1H/L, MU2H/L, DC motor relays MU1r/R, MU2r/R, and three-phase motor relays. Opens and closes MmU1, MmV1, and MmW1.

The controller 30 includes a three-phase controller 301 and a DC controller 40 . As shown in FIG. 15, the three-phase control unit 301 includes a current limit value calculation unit 311, a temperature estimation calculation unit 321, a phase current calculation unit 331, a three-phase to two-phase conversion unit 341, a current deviation calculator 351, and a controller 361. , a two-to-three phase converter 371 and a phase voltage/DC motor terminal voltage calculator 381 .

The dq-axis current command values Id ^* and Iq ^* calculated based on the steering torque Ts detected by the torque sensor 94 are input to the three-phase control unit 301 . A current limit value calculation unit 311 calculates dq-axis current command values Id1 ^{** and} Iq1 ^** after current limitation based on the dq-axis current command values Id* and Iq ^* and the estimated temperature H_est1. In order to prevent the inverter switching elements IU1H/L, IV1H/L, IW1H/L, etc. from exceeding the heat-resistant temperature due to temperature rise, the higher the estimated temperature H_est1, the lower the current limit value is set.

Based on phase currents Iu1, Iv1, and Iw1, temperature estimation calculation unit 321 calculates the temperature rise due to energization from the product (I ² R) of the current squared value and the resistance, and estimates the substrate temperature of inverter 601 . Generally, in three-phase motor control, the temperature rise is calculated based on the dq-axis current after coordinate transformation, but in this embodiment, the specific DC motor is also energized, so the temperature rise is calculated based on the current corresponding to the temperature estimation part. do. For example, the electric circuit is estimated based on the phase currents Iu1, Iv1, Iw1, and the coil is estimated based on the power supply current calculated based on the phase currents Iu1, Iv1, Iw1. Since it is necessary to use the phase current before subtracting the energized current as the temperature of the motor, a configuration different from the general three-phase motor control is adopted.

Based on the phase currents Iu1, Iv1, and Iw1 flowing through the inverter 601, the phase current calculation unit 331 supplies motor phase currents Iu1#, Iv1#, and Iw1# to the three-phase winding set 801 and to the specific DC motor. Calculate the DC currents I1 and I2 to be applied. The motor phase currents Iu1#, Iv1#, and Iw1# are output to the three-phase to two-phase conversion section 341 . DC current I1 or I2 calculated by phase current calculator 331 is output to DC controller 40 . Details of the phase current calculation will be described later with reference to FIG. 18 and the like.

The three-phase to two-phase conversion unit 341 coordinates-converts the motor phase currents Iu1#, Iv1#, Iw1# using the electrical angle θ, and feeds back the dq-axis currents Id1, Iq1 to the current deviation calculator 351 . A current deviation calculator 351 subtracts the dq-axis currents Id1 and Iq1 from the dq-axis current command values Id1 ^** and Iq1 ^** to calculate current deviations ΔId1 and ΔIq1. The controller 361 calculates the dq-axis voltage commands Vd1 and Vq1 by PI control or the like so that the current deviations ΔId1 and ΔIq1 approach zero. The two-to-three-phase conversion unit 371 performs coordinate conversion of the dq-axis voltage commands Vd1 and Vq1 using the electrical angle θ to calculate three-phase voltage commands Vu1, Vv1 and Vw1.

A phase voltage/DC motor terminal voltage calculation unit 381 calculates post-operation phase voltages Vu1# and Vv1 based on, for example, three-phase voltage commands Vu1, Vv1 and Vw1 and DC motor applied voltages Vx1 and Vx2 input from the DC control unit 40. #, Vw1# and DC motor terminal voltages Vm1 and Vm2 are calculated. However, depending on the embodiment, other calculations are also possible. Details of phase voltage and DC motor terminal voltage calculation will be described later with reference to FIGS.

As shown in FIG. 16( a ), the DC controller 40 has a current deviation calculator 45 and a controller 46 . A current deviation calculator 45 subtracts the DC currents I1 and I2 calculated by the phase current calculator 331 from the DC current command values I1 ^* and I2 ^* for the specific DC motor to calculate current deviations ΔI1 and ΔI2. The controller 46 calculates the voltages Vx1 and Vx2 applied to the DC motors 710 and 720 by PI control or the like so that the current deviations ΔI1 and ΔI2 approach 0, and the phase voltages of the three-phase control unit 301 and the DC motor terminal voltages Output to the calculation unit 381 . Further, as shown in FIG. 16B, without calculating the current deviation, the voltages Vx1 and Vx2 applied to the DC motors 710 and 720 are calculated from the DC current command values I1 ^* and I2 ^* by map calculation or the like. good too.

Next, the overall operation of the ECU 10 will be described with reference to the flowchart of FIG. In the description of the flow charts below, the symbol "S" indicates a step. Steps that are substantially the same as those in the above flowchart are assigned the same step numbers, and descriptions thereof are omitted. The routine of FIG. 17 starts when the vehicle switch 11 is turned on. S01 will be explained in the second and subsequent routines. In the first round after the start, that is, in the initial routine, NO is determined in S01, and the process proceeds to S11.

In the first routine, YES is determined in S11, and the process proceeds to S12. The control unit 30 drives the tilt actuator 710 and the telescopic actuator 720 in S12 to move the tilt and telescopic to the storage positions. Also, the control unit 30 releases the steering lock in S13. In the second round and subsequent routines, NO is determined in S11, and S12 and S13 are skipped.

The control unit 30 turns on the three-phase motor relays MmU1, MmV1, MmW1 and the DC motor relays MU1r/R, MU2r/R in S14 so that the three-phase motor 800 or the DC motors 710, 720 can be driven according to the torque request. state.

In S15-S22, a specific DC motor is selected from the two DC motors 710 and 720. FIG. In S15, the control unit 30 determines whether the absolute value |Ts| of the steering torque is less than the torque threshold Ts_th (eg, 5 [Nm]). Here, the steering torque Ts is defined as being positive in the left turning direction and negative in the right turning direction, depending on the direction of the torque applied to the steering wheel 91 . Since there is basically no difference in characteristics depending on the direction of rotation, the absolute value |Ts| of the steering torque is compared with the torque threshold value Ts_th including the steering torque Ts in both directions.

When the absolute value |Ts| of the steering torque is equal to or greater than the torque threshold Ts_th, that is, when the driver is steering the vehicle, it is determined NO in S15. Since it is preferable not to move the tilt or telescopic during steering, the DC motors 710 and 720 are not energized, and the process returns to before S01. On the other hand, when the absolute value |Ts| of the steering torque is less than the torque threshold value Ts_th, that is, when the driver is not substantially steering the vehicle, YES is determined in S15, and the process proceeds to S17.

In S17, it is determined whether the vehicle speed V is less than the vehicle speed threshold value V_th (for example, 30 [km/h]). When the vehicle speed V is equal to or greater than the vehicle speed threshold value V_th and the vehicle is traveling at high speeds when the determination in S17 is NO, it is preferable not to move the tilt or telescopic. Therefore, the tilt actuator 710 and the telescopic actuator 720 are not energized, and the process returns to before S01. On the other hand, when the vehicle speed V is less than the vehicle speed threshold value V_th and the vehicle is traveling at a low speed when S17 is YES, energization of the tilt actuator 710 and the telescopic actuator 720 is permitted.

If there is a tilt input from the tilt switch 12, YES is determined in S18, and the control unit 30 drives the tilt actuator 710 in S22. If NO in S18 and there is a telescopic input from the telescopic switch 13, YES is determined in S19, and the control unit 30 drives the telescopic actuator 720 in S23.

After the DC motors 710 and 720 have been driven in S22 and S23, or if NO is determined in S15 or S17, the process returns to before S01 and it is determined whether or not the vehicle switch 11 has been turned off. If the vehicle switch 11 remains on and the determination in S01 is NO, the routine after S11 is repeated. When the vehicle switch 11 is turned off and YES is determined in S01, the control unit 30 turns off the three-phase motor relays MmU1, MmV1, MmW1 and the DC motor relays MU1r/R, MU2r/R in S02. After that, in S03, the control unit 30 locks the steering and ends the process.

Next, phase current calculation processing by the phase current calculator 331 will be described with reference to the flowchart of FIG. 18 and the current waveform diagrams of FIGS. 27 and 28 . Here, one of DC motors 710 and 720 is energized as a "specific DC motor". The control unit 30 applies Kirchhoff's law to the current flowing from the inverter 601 to the three-phase winding set 801, and determines the motor phase current Iu1# supplied to the three-phase motor 800 and the current supplied to the specific DC motor 710. I1 or the current I2 supplied to the specific DC motor 720 is calculated.

Here, the phase to which the specific DC motor is connected is defined as "specific phase", and the phases other than the specific phase are defined as "non-specific phase". In this example, the U1 phase is the specific phase, and the V1 and W1 phases are the non-specific phases. In the following formulas, the last number "a" is omitted.

If the tilt actuator 710 is driven as the specific DC motor, YES is determined in S32, and the process proceeds to S35B. In S35B, the motor phase currents Iu1#, Iv1#, and Iw1# energized to the three-phase winding set 801 and the current I1 energized to the tilt actuator 710 are obtained by equations (1.1b) to (1.4b). calculated. It should be noted that the current I2 supplied to the telescopic actuator 720 is 0 as shown in Equation (1.5b).

Iu1#=-Iv1-Iw1 (1.1b)
Iv1#=Iv1 (1.2b)
Iw1#=Iw1 (1.3b)
I1=Iu1-Iu1# (1.4b)
I2=0 (1.5b)

In equation (1.1b), from the current values Iv1 and Iw1 detected by the current sensors SAV1 and SAW1 of the non-specific phases V1 and W1, according to Kirchhoff's law, the current value flowing through the specific phase U1 Iu1# is calculated as an estimated current value. In equation (1.4b), current I1 flowing through specific DC motor 710 is calculated from estimated current value Iu1# and current value Iu1 detected by current sensor SAU of the U1 phase, which is the specific phase.

When the telescopic actuator 720 is driven as the specific DC motor, NO is determined in S32, YES is determined in S33, and the process proceeds to S35C. Formulas (1.1c) to (1.3c) of S35C are the same as formulas (1.1b) to (1.3b) of S35B, and formulas (1.4b) and (1.5b) of S35B are Replaced by formulas (1.4c) and (1.5c).

Iu1#=-Iv1-Iw1 (1.1c)
Iv1#=Iv1 (1.2c)
Iw1#=Iw1 (1.3c)
I1=0 (1.4c)
I2=Iu1-Iu1# (1.5c)

FIG. 27 shows waveforms of the inverter phase currents Iu1, Iv1, and Iw1 flowing through the inverter 601. As shown in FIG. FIG. 28 shows waveforms of motor phase currents Iu1#, Iv1#, and Iw1# that are applied to three-phase winding set 801 in S35B and S35C. The inverter phase current Iu1 is offset with respect to the motor phase current Iu1# indicated by the two-dot chain line, and this offset corresponds to the DC current I1 or I2. When the DC motors 710 and 720 are energized simultaneously, this offset amount corresponds to the sum of the DC currents I1 and I2. The current of at least one of DC motors 710 and 720 may be detected, and DC currents I1 and I2 may be calculated from the sum of the detected current and DC currents I1 and I2. Alternatively, on the premise that the same current is flowing, values obtained by halving the sum may be calculated as the DC currents I1 and I2.

If the determination in S33 is NO, none of the DC motors 710 and 720 are driven, and the process proceeds to S35D. In S35D, motor phase currents Iu1#, Iv1#, and Iw1# applied to three-phase winding set 801 are calculated by equations (1.1d) to (1.3d). Also, the currents I1 and I2 supplied to the DC motors 710 and 720 are 0 as shown in equations (1.4d) and (1.5d).

Iu1#=Iu1 (1.1d)
Iv1#=Iv1 (1.2d)
Iw1#=Iw1 (1.3d)
I1=0 (1.4d)
I2=0 (1.5d)

In another embodiment, when the DC motor connected to the V1 phase is energized, the V1 phase is the specific phase, and the U1 and W1 phases are the non-specific phases. In this case, the estimated current value Iv1# of the specific phase is calculated according to Kirchhoff's law, and the current flowing through the specific DC motor is calculated from the estimated current value Iv1# and the detected current value Iv1 of the specific phase.

Also, when the DC motor connected to the W1 phase is energized, the W1 phase becomes the specific phase, and the U1 and V1 phases become non-specific phases. In this case, the estimated current value Iw1# of the specific phase is calculated according to Kirchhoff's law, and the current flowing through the specific DC motor is calculated from the estimated current value Iw1# and the detected current value Iw1 of the specific phase.

Next, with reference to FIGS. 19 to 26, flowcharts, schematic diagrams, voltage waveform diagrams, etc. of FIGS. 29 to 36, a plurality of patterns of arithmetic processing by the phase voltage and DC motor terminal voltage calculator 381 will be described. Branch number 1 of each pattern is processing for selecting an actuator to be driven. Branch number 2 is voltage calculation processing when one of the tilt actuator 710 or telescopic actuator 720 is driven, and branch number 3 is voltage calculation processing when both the tilt actuator 710 and telescopic actuator 720 are driven simultaneously. The figure with the branch number 1 and the figures with the branch numbers 2 and 3 are connected via connection symbols J1 to J5. J1 is for the first pattern, and the number following "J" indicates the number of the pattern.

Regarding the flowchart of each pattern, when the processing is common for each branch number 1 to 3, the diagram of the pattern described above is used. Also, "actuator" is written as "Act" in part of the flow chart. 26(a) or (b) and FIG. 30 are referred to by the first to fourth patterns, and FIGS. 26(c) and 36 are referred to by the fifth pattern. In FIG. 26, DC motor terminal voltages Vm1 and Vm2 corresponding to DC motors 710 and 720 are collectively denoted as "Vm", and applied voltages Vx1 and Vx2 are collectively denoted as "Vx".

Further, in the processing of branch numbers 2 and 3, for example, when the input voltage Vr1 or the control reference voltage Vref of the DC motor switches MU1H/L, MU2H/L or the inverter 601 is 12 [V], VH=10 [ V], VM=6 [V], and VL=2 [V], VH, VM, and VL are set as default values. Furthermore, the highest voltage VHH used in the third and fourth patterns is 12 [V] or a voltage slightly lower than 12 [V] (for example, 11.76 [V]), and the lowest voltage VLL is 0 [V]. Or a voltage slightly higher than 0 [V] (for example, 0.24 [V]). In terms of DUTY ratio, the highest voltage VHH corresponds to 98-100% and the lowest voltage VLL corresponds to 0-2%.

Normally, all DC motor switches MU1H/L and MU2H/L are turned off at the initial stage. Hereinafter, "to turn off the switch" includes not only the case of turning off from the ON state to the OFF state, but also the case of maintaining the initial OFF state. In this embodiment, the three-phase motor 800 and the DC motors 710 and 720 can be simultaneously energized by the calculations of the following first to fifth patterns, and the three-phase motor 800 and the DC motor 710 can be energized within the constraints of the power supply voltage. , 720 can be increased.

<First pattern>
The processing of the first pattern is shown in FIGS. 19 and 20. FIG. First, with reference to FIG. 19, the drive actuator selection processing for branch number 1 will be described. The first pattern is a basic form assuming that either the tilt actuator 710 or the telescopic actuator 720 is driven, or neither is driven. In S31 of FIG. 19, it is determined whether or not the output voltage of the three-phase motor 800 is less than a predetermined value, and if YES, the process proceeds to S32. If the output voltage of the three-phase motor 800 is equal to or higher than the predetermined value and it is determined NO in S31, the control unit 30 gives priority to ensuring the output voltage of the three-phase motor 800 and energizes the DC motors 710 and 720. Not performed.

If the tilt actuator 710 is to be driven, YES is determined in S32, and the process proceeds to S36B and S37B. At S36B, the DC motor relay MU1r/R is turned on and MU2r/R is turned off, and at S37B, one side of the tilt actuator 710 is driven.

If the telescopic actuator 720 is to be driven, it is determined NO in S32 and YES in S33, and the process proceeds to S36C and S37C. At S36C, the DC motor relay MU1r/R is turned off and MU2r/R is turned on, and at S37C, one side of the telescopic actuator 720 is driven.

If NO is determined in S31 or S33, none of the DC motors 710, 720 are driven, and the process proceeds to S36D, S37D. At S36D, the DC motor relay MU1r/R is turned off and MU2r/R is turned off, and at S37D normal control, that is, energization of only the three-phase motor 800 is performed.

Next, with reference to FIG. 20, the branch number 2 one-side drive processing will be described. As shown in FIG. 26A, in the first, second, and fifth patterns, the control unit 30 determines the post-operation voltage Vu1# and the applied voltage Vx, and then determines the DC motor terminal voltage Vm.

If energized in the forward direction, YES is determined in S41, and the process proceeds to S51F. In S51F, the neutral point voltage Vn1 is calculated according to equation (2.1). Thus, the control unit 30 adjusts the neutral point voltage Vn1 to be higher.
Vn1=-Vu1+VH (2.1)

When energizing in the negative direction, NO is determined in S41, YES is determined in S42, and the process proceeds to S51R. In S51R, the neutral point voltage Vn1 is calculated according to equation (2.2). Thus, the control unit 30 adjusts the neutral point voltage Vn1 to be low.
Vn1=-Vu1+VL (2.2)

In the first pattern, the formula number (2.3) is omitted. If there is no energization in either the positive direction or the negative direction, it is determined NO in S41 and NO in S42, and the process proceeds to S51N. In S51N, the neutral point voltage Vn1 is calculated according to equation (2.4).
Vn1=VM (2.4)

After S51F, S51R, and S51N, the process commonly proceeds to S54. In S54, the control unit 30 adds the neutral point voltage Vn1 to the voltage commands Vu1, Vv1, and Vw1 of each phase according to equations (3.1) to (3.3), and obtains the post-operation voltages Vu1#, Vv1#, and Vw1. Calculate #. Here, the phase voltage/DC motor terminal voltage calculator 381 in the control block diagram shown in FIG. 15 calculates the phase voltage using VH and VL as fixed values regardless of the phase voltage amplitude. In the following description of the phase voltage calculation, the “phase voltage/DC motor terminal voltage calculator 381” will be abbreviated as the “phase voltage calculator 381”.

As shown in FIG. 29(a), the voltage commands Vu1, Vv1, Vw1 before the phase voltage calculation process output by the two-to-three-phase converter 371 are sinusoidal with 0 [V] at the center. When the DC motors 710 and 720 are stopped, the phase voltage calculator 381 outputs a post-operation voltage command centered on VM (6 [V]), as shown in FIG. 29(b).

When DC motors 710 and 720 are driven, phase voltage calculator 381 shifts neutral point voltage Vn1 of three-phase motor 800 . As shown in FIG. 30A, when the U1 phase is energized in the positive direction, VH, which is the post-operation voltage Vu1# of the energized phase, is constant at 10 [V]. As shown in FIG. 30(b), when the U1 phase is energized in the negative direction, VL, which is the post-operation voltage Vu1# of the energized phase, is constant at 2 [V].

Vu1#=Vu1+Vn1 (3.1)
Vv1#=Vv1+Vn1 (3.2)
Vw1#=Vw1+Vn1 (3.3)

Although FIG. 30 shows an example in which the phase voltage amplitude of the waveform is 12 [V], the maximum value of the phase voltage amplitude is about 11 [V] considering the ON time of the lower arm element for current detection. VH in the DC motor terminal voltage calculation and the upper limit of the output voltage to the three-phase motor in S31 of FIG. 19 may be determined so that .

In FIG. 30, an example in which the upper limit of the phase voltage amplitude of the waveform is 12 [V] and the lower limit is 0 [V] is described. Even if VH in the DC motor terminal voltage calculation and the upper limit of the output voltage to the three-phase motor in S31 of FIG. good.

Further, a configuration in which control unit 30 adjusts neutral point voltage Vn1 according to the voltage applied to three-phase motor 800 will be described with reference to FIGS. 31 to 33. FIG. In the control block diagram of FIG. 31, an amplitude calculator 373 is added to FIG. The amplitude calculator 373 calculates the phase voltage amplitude using the following equation based on the dq-axis voltage commands Vd1 and Vq1. As indicated by the two-dot chain line, the amplitude calculator 373 may calculate the phase voltage amplitude based on the dq-axis current command values Id1 ^** and Iq1 ^** , or based on the detected current value and the rotation speed. A phase voltage amplitude may be calculated.
Phase voltage amplitude=√(2/3)×√(Vd1 ² +Vq1 ² )

The phase voltage calculator 381 calculates VH and VL using the following equations. Vmax is 12 [V], which is the input voltage Vr1 or the reference voltage Vref for control, or a voltage considering current detection by the current sensors SAU1, SAV1, SAW1 on the low potential side (for example, 93% of 12 [V] = 11.16 [V]). Vmin is 0 [V] or a voltage considering the pre-driver output (for example, 4% of 12 [V]=0.48 [V]).
VH=Vmax-(√3)×phase voltage amplitude VL=Vmin+(√3)×phase voltage amplitude

32 and 33 show examples in which the phase voltage amplitude increases with a constant gradient over three electrical angle periods (1080 [deg]). As shown in FIG. 32(a), the voltage commands Vu1, Vv1, and Vw1 before the phase voltage calculation processing output from the two-to-three-phase conversion unit 371 are sinusoidal with 0 [V] as the center and whose amplitude gradually increases. be. When the DC motors 710 and 720 are stopped, the phase voltage calculator 381 outputs a post-operation voltage command centered on VM (6 [V]), as shown in FIG. 32(b).

When DC motors 710 and 720 are driven, phase voltage calculator 381 shifts neutral point voltage Vn1 of three-phase motor 800 . As shown in FIG. 33A, when the U1 phase is energized in the positive direction, VH, which is the post-operation voltage Vu1# of the energized phase, changes from 12 [V] to about 10 [V] as the phase voltage amplitude increases. V]. The maximum value of the V1-phase and W1-phase voltages Vv1# and Vw1# is 12 [V]. As shown in FIG. 33(b), when the U1 phase is energized in the negative direction, VH, which is the post-operation voltage Vu1# of the energized phase, changes from 0 [V] to about 2 [V] as the phase voltage amplitude increases. V]. The minimum value of the V1-phase and W1-phase voltages Vv1# and Vw1# is 0 [V].

Returning to FIG. 20, in S55, the control unit 30 switches the inverter switching elements IU1H/L, IV1H/L, and IW1H/L so as to output the post-operation voltages Vu1#, Vv1#, and Vw1#.

In S61, when the tilt actuator 710 is driven on one side, the control unit 30 calculates the DC motor terminal voltage Vm1 by equation (4.1), and when the telescopic actuator 720 is driven on one side, the DC motor terminal voltage Vm1 is calculated by equation (4.2). A terminal voltage Vm2 is calculated.
Vm1=Vu1#-Vx1 (4.1)
Vm2=Vv1#-Vx2 (4.2)

In S65, the control unit 30 switches the DC motor switch MU1H/L or MU2H/L so as to output the DC motor terminal voltage Vm1 or Vm2.

After S54, the control unit 30 performs further flat-up modulation processing or flat-down modulation processing on the post-operation phase voltages Vu1#, Vv1#, and Vw1#, and outputs the phase voltages after the modulation processing in S55. Inverter switching elements IU1H/L, IV1H/L, and IW1H/L may be switched so as to operate.

<Second pattern>
The processing of the second pattern is shown in FIGS. 20-22. A second pattern is obtained by adding a case where both the tilt actuator 710 and the telescopic actuator 720 are simultaneously driven to the first pattern. In FIG. 21 showing the drive actuator selection process of branch number 1, S36A and S37A are added to FIG. 19 to proceed when YES in S32 and YES in S33. At S36A, the DC motor relay MU1r/R is turned on and MU2r/R is turned on, and at S37A, the tilt actuator 710 and the telescopic actuator 720 are simultaneously driven.

FIG. 20 of the first pattern is used for the one-sided driving process. Next, with reference to FIG. 22, the simultaneous drive processing for branch number 3 will be described. "T" is added to the end of the step number for steps related to simultaneous driving.

If both are energized in the forward direction, YES is determined in S41T, and the process proceeds to S51F. In S51F, the neutral point voltage Vn1 is calculated by the same equation (2.1) as for the one-side drive. If both are energized in the negative direction, it is determined NO in S41T and YES in S42T, and the process proceeds to S51R. In S51R, the neutral point voltage Vn1 is calculated by the same equation (2.2) as in the one-side drive.

If one is energized in the positive direction and the other is energized in the negative direction, it is determined NO in S41T, NO in S42T, and YES in S43T, and the process proceeds to S51X. In S51X, the neutral point voltage Vn1 is calculated by equation (2.3).
Vn1=-Vu1+VM (2.3)

If there is no energization in either the positive direction or the negative direction, NO is determined in S43T, and the process proceeds to S51N. In S51N, the neutral point voltage Vn1 is calculated by the same equation (2.4) as in the one-side drive. Subsequent S54 and S55 are the same as the one-side drive. In S61T, DC motor terminal voltages Vm1 and Vm2 are calculated using both equations (4.1) and (4.2). In S65T, the controller 30 switches the DC motor switches MU1H/L and MU2H/L to output the DC motor terminal voltages Vm1 and Vm2.

<Third pattern>
The processing of the third pattern is shown in FIGS. 19 and 23. FIG. As shown in FIG. 26B, in the third pattern, the controller 30 determines the DC motor terminal voltage Vm and the applied voltage Vx, and then determines the post-operation voltage Vu1#. For the processing of branch number 1, FIG. 19 of the first pattern is used.

When energizing in the positive direction in FIG. 23, YES is determined in S41, and the process proceeds to S44F. In S44F, when the tilt actuator 710 is driven on one side, the control unit 30 calculates the DC motor terminal voltage Vm1 from the equation (5.1f), and when the telescopic actuator 720 is driven on one side, the DC motor terminal voltage Vm1 is calculated from the equation (5.2f). A terminal voltage Vm2 is calculated.
Vm1=VLL (5.1f)
Vm2=VLL (5.2f)

When energizing in the negative direction, NO is determined in S41, YES is determined in S42, and the process proceeds to S44R. In S44R, when the tilt actuator 710 is driven on one side, the control unit 30 calculates the DC motor terminal voltage Vm1 from the equation (5.1r), and when the telescopic actuator 720 is driven on one side, the DC motor terminal voltage Vm1 is calculated from the equation (5.2r). A terminal voltage Vm2 is calculated.
Vm1=VHH (5.1r)
Vm2=VHH (5.2r)

If there is no energization in either the positive direction or the negative direction, it is determined NO in S41 and NO in S42, and the process proceeds to S44N. In S44N, when the tilt actuator 710 is driven on one side, the control unit 30 calculates the DC motor terminal voltage Vm1 from the equation (5.1n), and when the telescopic actuator 720 is driven on one side, the DC motor terminal voltage Vm1 is calculated from the equation (5.2n). A terminal voltage Vm2 is calculated.
Vm1=VM (5.1n)
Vm2=VM (5.2n)

In S46, the control unit 30 switches or turns on/off the DC motor switch MU1H/L or MU2H/L so as to output the DC motor terminal voltage Vm1 or Vm2. The specific on/off states of the DC motor switches MU1H/L and MU2H/L are shown in brackets of S44F, S44R, and S44N.

In other words, a switching operation with a duty ratio of 100% that outputs the maximum voltage VHH corresponds to "always on the switch on the high potential side" and "always off on the switch on the low potential side". A switching operation with a duty ratio of 0% that outputs the lowest voltage VLL corresponds to "always off of the high potential side switch" and "always on of the low potential side switch". A switching operation with a duty ratio of 50% that outputs the intermediate voltage VM corresponds to "always off of the switch on the high potential side" and "always off on the switch on the low potential side".

By only performing on/off switching without switching the DC motor switches MU1H/L and MU2H/L, it is possible to use transistors and mechanical relays with slow switching speeds, resulting in an inexpensive configuration. can.

Next, in S52, when the tilt actuator 710 is driven on one side, the control unit 30 calculates the neutral point voltage Vn1 according to the equation (6.1), and when the telescopic actuator 720 is driven on one side, the voltage Vn1 is expressed by the equation (6.2). The neutral point voltage Vn1 is calculated by
Vn1=Vm1+Vx1-Vu1 (6.1)
Vn1=Vm2+Vx2-Vv1 (6.2)

After S52, in S54 similar to the first and second patterns, the control unit 30 adds the neutral point voltage Vn1 to the voltage commands Vu1, Vv1, and Vw1 of each phase, and obtains the post-operation voltages Vu1#, Vv1#, Calculate Vw1#. The post-operation voltage Vu1# becomes "Vm1+Vx1" or "Vm2+Vx2". Note that the solid top modulation process or the bottom solid modulation process is not applied to the third pattern. Then, in S55 similar to the first and second patterns, the control unit 30 switches the inverter switching elements IU1H/L, IV1H/L, and IW1H/L so as to output the post-operation voltages Vu1#, Vv1#, and Vw1#. switch.

As described above, for example, when the specific DC motor 710 is energized in the positive direction, the control unit 30 turns on the low-potential-side DC motor switch MU1L connected to the second terminal, or connects the DC motor switch MU1L to the second terminal T2. The low-potential-side and high-potential-side DC motor switches MU1H/L are switched so that the voltage of the second terminal T2 becomes lower than the voltage of the first terminal T1, and the neutral of the three-phase winding set 801 is switched. An operation is performed to increase the point voltage Vn1. In the second pattern, when simultaneously energizing a plurality of specific DC motors 710 and 720 connected to the same single phase (U1 phase in this example) of the three-phase winding set 801, the control unit 30 rotates in the forward direction. The DC motor to be energized is switched in the same manner as when energized in the forward direction.

For example, when energizing the specific DC motor 710 in the negative direction, the control unit 30 turns on the high potential side DC motor switch MU1H connected to the second terminal, or turns on the low potential side DC motor switch MU1H connected to the second terminal T2. The DC motor switches MU1H/L on the potential side and the high potential side are switched so that the voltage of the second terminal T2 becomes higher than the voltage of the first terminal T1, and the neutral point voltage Vn1 of the three-phase winding set 801 is switched. be operated to lower the In the second pattern, when simultaneously energizing a plurality of specific DC motors 710 and 720 connected to the same single phase (U1 phase in this example) of the three-phase winding set 801, The DC motor to be energized is switched in the same manner as in the negative direction energization described above.

<Fourth pattern>
The processing of the fourth pattern is shown in FIGS. 21, 24 and 25. FIG. As shown in FIG. 26(c), in the fourth pattern, the control unit 30 does not directly use the applied voltage Vx, but determines the DC motor terminal voltage Vm and the post-operation voltage Vu1# according to the positive/negative of the current flow direction. It should be noted that the positive/negative direction of current flow is based on applied voltages Vx1 and Vx2 and current commands I1 ^* and I2 ^* . In the fourth pattern, since the applied voltages Vx1 and Vx2 are not used, the amount of calculation of the control section 30 can be reduced. Further, if the DC motor switch MU1H/L or MU2H/L is simply turned on/off, the operation is simplified, making it easier to find an abnormality.

For the processing of branch number 1, FIG. 21 of the second pattern is used. In the one-side driving process of branch number 2 shown in FIG. 24, S41, S42, S51F, S51R, S51N, S54, and S55 are the same as those in FIG. 20 for the first and second patterns. After S55, if the current is applied in the positive direction, the process proceeds to S64F. If the current is applied in the negative direction, the process proceeds to S64R. If the current is not applied in the positive or negative direction, the process proceeds to S64N.

At S64F, S64R and S64N, the control unit 30 calculates the DC motor terminal voltages Vm1 and Vm2 in the same manner as S44F, S44R and S44N of the third pattern. Furthermore, in S66, the control unit 30 causes the DC motor switch MU1H/L or MU2H/L to switch or turn ON/OFF so as to output the DC motor terminal voltage Vm1 or Vm2, as in S46 of the third pattern. turn off.

In the simultaneous driving process of branch number 3 shown in FIG. 25, S41T, S42T, S43T, S51F, S51R, S51X, S51N, S54, and S55 are the same as those of the second pattern shown in FIG. After S55, when both are energized in the positive direction, the process proceeds to S64FF, and when both are energized in the negative direction, the process proceeds to S64RR.

When one is energized in the positive direction and the other is energized in the negative direction, and the tilt actuator 710 is in the positive direction, YES is determined in S63, and the process proceeds to S64FR. When one is energized in the positive direction and the other is energized in the negative direction, and the telescopic actuator 720 is in the positive direction, NO is determined in S63, and the process proceeds to S64RF. If there is no energization in either the positive direction or the negative direction, the process proceeds to S64NN.

In S64FF, the control unit 30 calculates the DC motor terminal voltage Vm1 using the equation (7.1f), and calculates the DC motor terminal voltage Vm2 using the equation (7.2f).
Vm1=VLL (7.1f)
Vm2=VLL (7.2f)

At S64RR, the control unit 30 calculates the DC motor terminal voltage Vm1 from the equation (7.1r), and calculates the DC motor terminal voltage Vm2 from the equation (7.2r).
Vm1=VHH (7.1r)
Vm2=VHH (7.2r)

At S64FR, the control unit 30 calculates the DC motor terminal voltage Vm1 from the equation (7.1f), and calculates the DC motor terminal voltage Vm2 from the equation (7.2r).
Vm1=VLL (7.1f)
Vm2=VHH (7.2r)

In S64RF, the control unit 30 calculates the DC motor terminal voltage Vm1 using the equation (7.1r), and calculates the DC motor terminal voltage Vm2 using the equation (7.2f).
Vm1=VHH (7.1r)
Vm2=VLL (7.2f)

At S64NN, the control unit 30 calculates the DC motor terminal voltage Vm1 from the equation (7.1n), and calculates the DC motor terminal voltage Vm2 from the equation (7.2n).
Vm1=VM (7.1n)
Vm2=VM (7.2n)

In S66T, the control unit 30 switches or turns on/off the DC motor switches MU1H/L and MU2H/L so as to output the DC motor terminal voltages Vm1 and Vm2. The concept of switching on/off is the same as in S46 of the third pattern.

<Fifth pattern>
The processing of the fifth pattern is shown in FIGS. 21, 34 and 35. FIG. Also refer to the voltage waveforms in FIG. As shown in FIG. 36, in the fifth pattern, the post-operation voltage Vu1# of the U1 phase is not set to a constant voltage, but is shifted by a constant VH, VL or VM with respect to the voltage command Vu1. That is, the control unit 30 determines the DC motor terminal voltage Vm1 such that the difference between the post-operation voltage Vu1# and the DC motor terminal voltage Vm1 becomes the applied voltage Vx1.

For the processing of branch number 1, FIG. 21 of the second pattern is used. In the one-side driving process of branch number 2 shown in FIG. 34, when energizing in the positive direction, in S53F, the neutral point voltage Vn1 is calculated by equation (8.1). When energizing in the negative direction, in S53R, the neutral point voltage Vn1 is calculated according to equation (8.2).

Vn1=VH (8.1)
Vn1=VL (8.2)

S51N in the case of no energization in either the positive direction or the negative direction is the same as in FIG. 20 for the first and second patterns. After S53F, S53R, and S51N, S54, S55, S61, and S65 are the same as in FIG. 20 for the first and second patterns. After S54, the control unit 30 may further perform flat top modulation processing or flat bottom modulation processing before proceeding to S55.

In the simultaneous driving process of branch number 3 shown in FIG. 35, when both are energized in the positive direction, YES is determined in S41T, and the process proceeds to S53F. In S53F, the neutral point voltage Vn1 is calculated by the same equation (8.1) as in the one-side drive. If both are energized in the negative direction, it is determined NO in S41T and YES in S42T, and the process proceeds to S51R. In S53R, the neutral point voltage Vn1 is calculated by the same equation (8.2) as for the one-side drive.

If one is energized in the positive direction and the other is energized in the negative direction, it is determined NO in S41T, NO in S42T, and YES in S43T, and the process proceeds to S53X. In S53X, the neutral point voltage Vn1 is calculated by equation (8.3).
Vn1=VM (8.3)

S51N in the case where neither the positive direction nor the negative direction is energized is the same as in FIG. 22 for the second pattern. After S53F, S53R, S53X, and S51N, S54, S55, S61T, and S65T are the same as in FIG. 22 of the second pattern.

Since the arithmetic processing of each pattern described above applies a voltage to the DC motors 710 and 720 when there is a voltage margin for shifting the neutral point voltage Vn1, the DC motors 710 and 720 are applied to the three-phase motor 800. On the other hand, the smaller the output, the better. Further, it is preferable that the DC motors 710 and 720 have smaller electric current than the three-phase motor 800, have a large resistance, and have a large time constant.

Next, the operation immediately after the vehicle switch is turned on will be described with reference to the flowchart of FIG. 37 and the circuit configuration diagram of FIG. FIG. 38 shows a state of energizing the tilt actuator 710 and the telescopic actuator 720 in the configuration of FIG. 6 of the second embodiment. Here, it is assumed that there are no DC motor relays MU1r/R, MU2r/R, MV3r/R, and MV4r/R. In a configuration with the DC motor relays MU1r/R, MU2r/R, MV3r/R, and MV4r/R, the DC motor relays MU1r/R, MU2r/R, MV3r/R, and MV4r/R are activated at least when the corresponding DC motor is energized. shall be turned on.

In this embodiment, there is a demand to move the seat position, tilt and telescopic positions to the stored positions as quickly as possible immediately after the vehicle switch is turned on as shown in S01 in FIG. Therefore, when the steering torque absolute value |Ts| In the following specification, "the seat motors 730, 740 are at the memory position" is omitted from the phrase "the seat motors 730, 740 are at the memory position" and will be written as "the seat motors 730, 740 are at the memory position."

Completion flag 1 in FIG. 37 is off when the first sheet motor 730 is at a position other than the storage position, and is turned on when the first sheet motor 730 reaches the storage position. The completion flag 2 is off when the second sheet motor 740 is at a position other than the storage position, and is turned on when the second sheet motor 740 reaches the storage position. Completion flag 3 is off when the tilt is outside the storage position, and is on when the tilt reaches the storage position. Completion flag 4 is off when the telescopic is outside the storage position, and is on when the telescopic reaches the storage position. At S71 immediately after the vehicle switch is turned on, the completion flags 1 to 4 are all set to off as initial values.

In S72, the control unit 30 turns off all the high potential side DC motor switches MU1H, MU2H, MV3H and MV4H, turns on the low potential side DC motor switches MU1L, MU2L, MV3L and MV4L, and turns on the DC motor switches MU1L, MU2L, MV3L and MV4L. The inverter switching elements IU1H and IV1H on the high potential side of the phase to which 710 to 740 are connected are turned on, and the inverter switching elements IU1L and IV1L on the low potential side are turned off. S73 and subsequent steps are described on the premise of this initial state. In this way, the three-phase motor 800 is not energized, and the DC motors 710 to 740 are simultaneously energized.

Alternatively, the control unit 30 turns on all the high potential side DC motor switches MU1H, MU2H, MV3H, and MV4H, and turns off the low potential side DC motor switches MU1L, MU2L, MV3L, and MV4L, and The inverter switching elements IU1H and IV1H on the high potential side of the phase to which the DC motors 710 to 740 are connected may be turned off, and the inverter switching elements IU1L and IV1L on the low potential side may be turned on.

Further, if it is desired to change the energizing direction of each of the DC motors 710 to 740 depending on conditions such as seat position, tilt or telescopic position, the following may be done. First, the inverter switching elements IU1H and IV1H on the high potential side and the inverter switching elements IU1L and IV1L on the low potential side are switched at the same DUTY ratio such as 50%. Then, depending on the direction in which the DC motors are to be energized, the high potential side DC motor switches MU1H, MU2H, MV3H, and MV4H are turned off, and the low potential side DC motor switches MU1L, MU2L, MV3L, and MV4L are turned on. , turn on the inverter switching elements IU1H and IV1H on the high potential side, and turn off the inverter switching elements IU1L and IV1L on the low potential side.

Power supply to the three-phase motor 800 is stopped by switching the inverter switching elements IU1H/L and IV1H/L of each phase at the same DUTY ratio, or by turning off the inverter switching elements on the high potential side and the low potential side. , DC motor switches MU1H/L, MU2H/L, MV3H/L, and MV4H/L are switched or switched to change the DC motor terminal voltages Vm1, Vm2, Vm3, and Vm4, thereby energizing the three-phase motor 800. Each of the DC motors 710 to 740 can be energized at the same time.

In S73, it is determined whether the first sheet motor 730 has reached the storage position or whether the completion flag 1 is ON. If YES in S73, the DC motor switch MV3L is turned off in S741. At this time, the completion flag 1 is on. If NO in S73, the MV3L is kept on in S742, and the energization of the first sheet motor 730 is continued.

In S75, it is determined whether the second sheet motor 740 has reached the storage position or whether the completion flag 2 is ON. If YES in S75, the DC motor switch MV4L is turned off in S761. At this time, the completion flag 2 is on. FIG. 38 shows the current paths at this point. If NO in S75, the MV4L is kept on in S762, and energization of the second sheet motor 740 is continued.

In S77, it is determined whether the tilt has reached the storage position or whether the completion flag 3 is ON. If YES in S77, the DC motor switch MU1L is turned off in S781. At this time, the completion flag 3 is on. If NO in S77, MU1L is maintained in the ON state in S782, and energization of the tilt actuator 710 is continued.

In S79, it is determined whether the telescopic has reached the storage position or whether the completion flag 4 is ON. If YES in S79, the DC motor switch MU2L is turned off in S801. At this time, the completion flag 4 is on. In the case of NO in S79, MU2L is kept on in S802, and energization of the telescopic actuator 720 is continued.

At S81, it is determined whether all of the completion flags 1 to 4 are ON. If all completion flags 1 to 4 are ON and S81 is YES, the process ends. On the other hand, if any of the completion flags 1 to 4 is off, NO is determined in S81, the process returns to S73, and the determination steps of S73, S75, S77, and S79 are repeated. Although not shown, the inverter switching element IV1H is turned off after the completion flags 1 and 2 are turned on, and the inverter switching element IU1H is turned off after the completion flags 3 and 4 are turned on.

Next, with reference to FIGS. 39 to 43, control for driving and stopping the DC motor during driving of the three-phase motor will be described. In this part of the description, only "710" is used as the reference for the DC motor. When the two specific DC motors 710 and 720 connected in the same phase are energized at the same time, the total current flowing through each DC motor 710 and 720 is interpreted as DC current. Also, although not mentioned in the above description, the control unit 30 detects an abnormality such as an overcurrent abnormality in the inverter 601 or the three-phase motor 800 .

FIG. 39 shows a flowchart for switching between driving and stopping the DC motor 710 while the three-phase motor 800 is being driven. The control unit 30 switches between driving and stopping the DC motor 710 by manipulating the neutral point voltage Vn1 based on a predetermined condition described below. In S91, it is determined whether the vehicle switch 11 is off, that is, when the vehicle is stopped. If YES, the control unit 30 ends the process. If the vehicle switch 11 is on and S91 is NO, the process proceeds to S92.

In S92, as "on determination", the start of energization to the DC motor 710 is determined based on the AND conditions of the following items. If the conditions for all items are satisfied, YES is determined in S92, and the process proceeds to "ON processing" in S93 to S95. If even one item does not satisfy the condition, the process returns to before S91.
[1] Drive signal = ON.
[2] The phase voltage amplitude is smaller than the threshold Vth1 and the phase current amplitude is smaller than the threshold Ith1.
[3] No abnormality detected in inverter 601 or three-phase motor 800, that is, normal.

The drive signal [1] is used when the vehicle is initially driven, when the tilt switch 12 is input by the driver, or when a command signal to drive the DC motor 710 is notified from another ECU. turned on. In the case of the DC motor 720, the drive signal is turned on when the telescopic switch 13 is input.

[2] indicates that the output of the inverter 601 has a margin. When the phase voltage amplitude is smaller than the threshold value Vth1 and the phase current amplitude is smaller than the threshold value Ith1, it is determined that the power supply to the three-phase motor 800 is small and that there is enough power to be distributed to the DC motor 710 . The phase voltage amplitude may be a value that correlates with the amplitude of the phase voltage command, and the phase current amplitude may be a value that correlates with the amplitude of the actual phase current. For example, the number of revolutions of the three-phase motor 800 may be used as a value correlated with the phase voltage amplitude and the phase current amplitude. A current command value may be used as the phase current amplitude. All of [1], [2], and [3] may be determined, or only a part of them may be determined. Alternatively, the determination may be made based on the absolute value |Ts| of the steering torque and the vehicle speed V described in FIG.

In S93 of ON processing, the fail-safe threshold value switching flag for the fail-safe threshold value in the abnormality detection of the inverter 601 or the three-phase motor 800 is turned ON. As a result, the control unit 30 increases the threshold for judging an overcurrent for the three-phase current by the amount of the current expected to flow through the DC motor 710 . In addition to the fail-safe threshold for abnormality detection for the three-phase motor 800, a fail-safe threshold for abnormality detection of the circuit and the DC motor 710 may be set. At S94, the current detection switching flag is turned on. In S95, the "DC motor energization start process" corresponding to the period from time t1 to t3 in FIGS. 42 and 43 is executed, and the DC motor 710 is driven.

In this manner, the control unit 30 switches the fail-safe threshold value in abnormality detection between when the DC rotary machine DC motor 710 is driven and when it is not driven. 40 and 41 show flow chart examples 1 and 2 of fail-safe threshold switching. In example 1 shown in FIG. 40, if the fail-safe threshold switching flag is off in S930, the fail-safe threshold is set to A in S931, and if the fail-safe threshold switching flag is on, the fail-safe threshold is set to B (> A).

In Example 2 shown in FIG. 41, if the fail-safe threshold switching flag is off in S930, it is determined whether the absolute value of the three-phase current sum (|Iu1+Iv1+Iw1|) is greater than C in S933. If the fail-safe threshold switching flag is ON, it is determined in S934 whether the absolute value (|Iu1+Iv1+Iw1|) of the three-phase current sum is greater than (C+D). If YES in S933, the controller 30 increments the abnormality counter in S935. In the case of YES in S934, the controller 30 increments the abnormality counter in S936.

For the processing when the current detection switching flag is turned on, the flowchart of phase current calculation in FIG. 18 is referred to. That is, when the current detection switching flag is ON, the motor phase currents Iu#, Iv#, Iw# and DC currents I1, I2 are calculated by the equations of S35B and S35C. On the other hand, when the current detection switching flag is off, the motor phase currents Iu#, Iv#, and Iw# are calculated by the equation of S35D.

Returning to FIG. 39, in S96, as "off determination", the end of energization to the DC motor 710 is determined based on the OR conditions of the following items. If even one item satisfies the condition, YES is determined in S96, and the process proceeds to "off processing" in S97 to S99. If none of the conditions are met, the process returns to S96.
[1] Drive signal = off.
[2] The phase voltage amplitude is greater than the threshold Vth2, or the phase current amplitude is greater than the threshold Ith2.
[3] An abnormality in inverter 601 or three-phase motor 800 has been detected.

The drive signal [1] is turned off when the tilt switch 12 is turned off by a driver operation, or when a command signal to stop the DC motor 710 is notified from another ECU. In the case of the DC motor 720, the drive signal is turned off when the telescopic switch 13 is turned off.

[2] indicates that the output of the inverter 601 has no margin. When the phase voltage amplitude is greater than the threshold Vth2 or the phase current amplitude is greater than the threshold Ith2, it is determined that the power supply to the three-phase motor 800 is large and there is no margin for the output to be distributed to the DC motor 710 . On/off hysteresis may be provided by setting Vth1<Vth2 and Ith1<Ith2 for thresholds for ON determination and OFF determination. All of [1], [2], and [3] may be determined, or only a part of them may be determined. Alternatively, the determination may be made based on the absolute value |Ts| of the steering torque and the vehicle speed V described in FIG.

In the off process, the process is performed in the reverse order of the on process. In S97, the "power-on completion process for the DC motor" corresponding to the period from time t4 to t6 in FIGS. 42 and 43 is executed, and the DC motor 710 is stopped. At S98, the current detection switching flag is turned off. At S99, the fail-safe threshold switching flag is turned off. As a result, the threshold changed while the DC motor 710 is being energized is returned to the original value. After that, the process returns to before S91, and the routine is repeated.

In the flowchart of FIG. 39, the sequence in which the OFF determination is executed after the completion of the ON process is described. Conversely, if the ON determination is satisfied during the energization termination process for the DC motor, the process may proceed to the ON process. Further, in order to avoid switching between ON and OFF, it may be arranged such that after the OFF process, the second ON determination is not accepted for a predetermined period (for example, about several 100 ms).

42 and 43 show control examples 1 and 2 when the DC motor 710 is driven and stopped while the three-phase motor 800 is being driven. /OFF and changes in the DC current I1 flowing through the DC motor 710. FIG. As indicated by the vertical axis of each phase voltage, each phase voltage may be converted into a DUTY ratio with 12 [V] as 100%. Also, the switch for the low-potential side DC motor is abbreviated as "lower switch", and only the symbol "MU1L" is described.

First, ignoring minor differences between control examples 1 and 2, the overall operation will be described. Mainly, when the driving of the DC motor 710 is stopped, the control unit 30 reduces the current on the inverter 601 side and then turns off the lower switch MU1L. Therefore, as described with reference to FIG. 39, for example, when the phase voltage amplitude is equal to or greater than the threshold value Vth1 at the time of ON determination, the control unit 30 does not energize the DC motor 710 . Further, when the phase voltage amplitude exceeds the threshold value Vth2 while the DC motor 710 is being energized, the control unit 30 terminates the energization of the DC motor 710 . It should be noted that the thresholds Vth1 and Vth2 are preferably set to voltage values with some leeway in consideration of the time required for starting and stopping.

The average value or average equivalent value of each phase voltage in the three-phase motor 800 decreases from 6 [V] to VLx near 0 [V] (for example, about 1 [V]) at time t1, and then decreases at time t2. When the switch MU1L is turned on, the voltage rises from VLx and reaches VHx near 12 [V] (for example, about 11 [V]) at time t3. At this time, the DC current increases from 0 to the maximum value I ₁₀₀ as the voltage of each phase changes, and then is maintained at that state.

When it is determined that energization of DC motor 710 is finished, control unit 30 operates inverter switching elements IU1H/L, IV1H/L, and IW1H/L at time t4 to reduce each phase voltage. Then, at time t6 after time t5 when the average value of each phase voltage or the average equivalent value has decreased to VLx, the control unit 30 turns off the lower switch MU1L. In simple words, the control unit 30 turns off the lower switch MU1L after reducing the current so that the current on the inverter 601 side gradually decreases.

Thus, when the DC motor 710 is stopped, the control unit 30 operates the inverter switching elements IU1H/L, IV1H/L, and IW1H/L to reduce the voltage on the first terminal T1 side of the DC motor 710. , the lower switch MU1L is turned off, and energization of the DC motor 710 is terminated. As a result, even if a switch with a relatively small current capacity is used as the DC motor switch MU1H/L, it is possible to avoid overloading the lower switch MU1L when the current is stopped. In addition, transistors and mechanical relays with slow switching operations can be used on the premise that high-speed switching operations are not performed.

Next, control example 1 and control example 2 differ in phase voltage calculation of the energized phase U1 in the period immediately before the lower switch MU1L is turned on and the period before and after it is turned off, ie, the period from time t1 to t2 and from time t5 to t7. In Control Example 1, the neutral point voltage Vn1 is shifted so that the phase voltage Vu1# of the U1 phase, which is the energized phase, is kept constant. In this case, U1-phase voltage Vu1# does not completely reach 0 [V] at times t2 and t6 when lower switch MU1L is turned on or off. A DC current I1 corresponding to a constant phase voltage Vu1# flows during a period from time t5 to time t6 before the lower switch MU1L is turned off.

On the other hand, in control example 2, the neutral point voltage Vn1 is shifted while the three-phase voltage is a sine wave during the periods of time t1 to t2 and time t5 to t7. Then, as shown in the bottom enlarged view, the timing at which the U1 phase voltage Vu1# is exactly 0 [V] (or the U1 phase DUTY ratio is exactly 0 [%]), The control unit 30 turns on or off the lower switch MU1L at the timing when the current becomes 0 considering the delay of the time constant. Then, the control unit 30 starts increasing the voltage of each phase after a minute time δT has elapsed from the time t2. During the period from time t5 to time t6 before the lower switch MU1L is turned off, a DC current I1 corresponding to the sinusoidal phase voltage Vu1# flows. In Control Example 2, the voltage applied from the inverter 601 can be ideally set to 0 when the lower switch MU1L is turned on or off.

[Circuit configuration for driving a two-system, three-phase motor]
Next, an embodiment in which a two-system three-phase motor 800 is driven will be described. First, with regard to the structure of the three-phase motor 800, a configuration example of a "electromechanically integrated motor" in which the ECU 10 is integrally configured on one side in the axial direction will be described with reference to FIGS. 44 and 45. FIG. In the form shown in FIG. 44 , the ECU 10 is arranged coaxially with the axis Ax of the shaft 87 on the side opposite to the output side of the three-phase motor 800 . Note that, in another embodiment, the ECU 10 may be configured integrally with the three-phase motor 800 on the output side of the three-phase motor 800 . The three-phase motor 800 is a brushless motor and includes a stator 840, a rotor 860, and a housing 830 containing them.

Stator 840 has a stator core 844 fixed to housing 830 and two sets of three-phase winding sets 801 and 802 assembled to stator core 844 . Lead wires 851 , 853 , and 855 extend from each phase winding that constitutes a first system three-phase winding set (hereinafter “first three-phase winding set”) 801 . Lead wires 852 , 854 , and 856 extend from each phase winding that constitutes a three-phase winding set (hereinafter referred to as “second three-phase winding set”) 802 of the second system. Each phase winding is wound in each slot 848 of stator core 844 .

The rotor 860 has a shaft 87 supported by a rear bearing 835 and a front bearing 836, and a rotor core 864 in which the shaft 87 is fitted. Rotor 860 is provided inside stator 840 and is rotatable relative to stator 840 . A permanent magnet 88 for rotation angle detection is provided at one end of the shaft 87 .

The housing 830 has a bottomed tubular case 834 including a rear frame end 837 and a front frame end 838 provided at one end of the case 834 . The case 834 and the front frame end 838 are fastened together with bolts or the like. The lead wires 851 and 852 of the three-phase winding sets 801 and 802 are inserted through the lead wire insertion hole 839 of the rear frame end 837 and extended to the ECU 10 side to be connected to the board 230 .

The ECU 10 includes a cover 21, a heat sink 22 fixed to the cover 21, a substrate 230 fixed to the heat sink 22, and various electronic components mounted on the substrate 230. The cover 21 protects the electronic components from external shocks and prevents dust, water, and the like from entering the ECU 10 . The cover 21 has a connector portion 214 for external connection of a power supply cable or a signal cable from the outside, and a cover portion 213 . The power supply terminals 215 and 216 of the external connection connector section 214 are connected to the board 230 via paths (not shown). Note that the connectors are denoted by different reference numerals from those in FIG.

The board 230 is, for example, a printed board, is provided at a position facing the rear frame end 837 and is fixed to the heat sink 22 . On the substrate 230, electronic components for two systems are provided independently for each system. The number of substrates 230 is not limited to one, and may be two or more. Of the two main surfaces of the substrate 230 , the surface facing the rear frame end 837 is the motor surface 237 , and the opposite surface, that is, the surface facing the heat sink 22 is the cover surface 238 .

A plurality of switching elements 241 , 242 , rotation angle sensors 251 , 252 , custom ICs 261 , 262 , etc. are mounted on the motor surface 237 . A plurality of switching elements 241 and 242 correspond to IU1H/L and the like in each block diagram of the ECU, and constitute three-phase upper and lower arms of each system. The rotation angle sensors 251 and 252 are arranged so as to face a permanent magnet 88 provided at the tip of the shaft 87 . Custom ICs 261 and 262 and microcomputers 291 and 292 have control circuits for the ECU 10 . The rotation angle sensors 251, 252, microcomputers 291, 292, etc. may not be provided two each for each system, but may be provided one for each of the two systems.

Microcomputers 291 and 292 , capacitors 281 and 282 , inductors 271 and 272 and the like are mounted on the cover surface 238 . In particular, the first microcomputer 291 and the second microcomputer 292 are arranged on the cover surface 238 on the same side of the substrate 230 with a predetermined gap therebetween. The capacitors 281 and 282 smooth the power input from the power supply and prevent outflow of noise caused by switching operations of the switching elements 241 and 242 and the like. The inductors 271, 272 and the capacitors 281, 282 correspond to L1, C1, etc. in each configuration diagram of the ECU, and constitute a "noise prevention element" functioning as a noise filter.

As shown in FIG. 46, a three-phase motor 800 is a three-phase double winding rotating machine in which two sets of three-phase winding sets 801 and 802 are coaxially provided. A voltage is applied to the U1-phase, V1-phase, and W1-phase windings 811 , 812 , and 813 of the first three-phase winding set 801 from a first system inverter (hereinafter “first inverter”) 601 . A voltage is applied to the U2-phase, V2-phase, and W2-phase windings 821 , 822 , and 823 of the second three-phase winding set 802 from an inverter (hereinafter “second inverter”) 602 of the second system.

The first three-phase winding set 801 and the second three-phase winding set 802 have the same electrical characteristics, and are arranged, for example, on a common stator 840 with an electrical angle of 30 [deg] shifted from each other. In that case, the back electromotive voltage generated in each phase of the first system and the second system is based on the voltage amplitude A, the rotation speed ω, and the phase θ, for example, formulas (9.1) to (9.3), (9 .4a) to (9.6a).

Eu1=-Aω sin θ (9.1)
Ev1=-Aω sin(θ-120) (9.2)
Ew1=-Aωsin(θ+120) (9.3)
Eu2=-Aωsin(θ+30) (9.4a)
Ev2=-Aωsin(θ-90) (9.5a)
Ew2=-Aωsin(θ+150) (9.6a)

If the phase relationship between the two systems is reversed, for example, the phase (θ+30) of the U2 phase becomes (θ−30). Furthermore, a phase difference equivalent to 30 [deg] is generalized and expressed as (30±60×k) [deg] (k is an integer). Alternatively, the second system may be arranged in phase with the first system. In that case, the back electromotive force generated in each phase of the second system is represented by equations (9.4b) to (9.6b) instead of equations (9.4a) to (9.6a).

Eu2=-Aωsin(θ-30) (9.4b)
Ev2=-Aωsin(θ+90) (9.5b)
Ew2=-Aωsin(θ-150) (9.6b)

Next, configuration examples of the ECU 10 that drives the two-system, three-phase motor 800 will be described as eleventh and twelfth embodiments with reference to FIGS. 47 and 48 . A three-phase motor 800 is a combination of the first three-phase winding set 801 and the second three-phase winding set 802 . Let Vn2 be the symbol of the operating voltage at the neutral point of the second three-phase winding set 802 . Reference numeral "800" for the three-phase motor and reference numerals "821, 822, 823" for the three-phase windings of the second three-phase winding set 802 are shown only in FIG. 47 and omitted from FIG.

The ECU 10 of the eleventh and twelfth embodiments has two inverters 601 and 602 . The symbols of the inverter switching elements, current sensors, motor relays, etc. of the second system are represented by replacing the symbol "1" of the first system with "2". Regardless of the configuration of the power supply, the DC voltage input to second inverter 601 is referred to as "input voltage Vr2".

The control unit 30 in the two-system configuration includes three-phase control units of the first system and the second system according to FIG. 15 and a DC control unit according to FIG. In the two-system configuration, the total number and distribution of DC motors connected to each phase of the first system and the second system are determined according to needs. The distribution of DC motors is determined in consideration of power balance between systems, heat generation balance, use frequency and use timing balance, and the like.

(Eleventh embodiment)
In the eleventh embodiment shown in FIG. 47, the first inverter 601 and the second inverter 602 are connected to a common power source Bt1, and two DC motors 710 and 720 are connected to the U1 phase of the first three-phase winding set 801. is connected. DC motor relays MU1r/R and MU2r/R are provided between the branch point Ju of the U1-phase current path and the first terminals of the DC motors 710 and 720, respectively. On the other hand, the DC motor is not connected to the second three-phase winding set 802 . In the eleventh embodiment, since the DC motor is connected only to some of the multiple systems, the roles of each system are shared.

(Modified example of the eleventh embodiment)
47, one or more DC motors may be connected to any phase of the second system. For example, similar to the first system, a configuration in which two DC motors are connected to the U2 phase of the second system improves the balance between the systems.

In addition, as in a configuration in which two or more DC motors are connected to the U1 phase of the first system and one DC motor is connected to the U2 phase of the second system, the number of DC motors connected to the first system The number may be greater than the number of DC motors connected to the second system. For example, by arranging a large number of DC motors for relatively small power actuators such as the steering position system in the first system and arranging a few DC motors for relatively large power actuators such as the seat system in the second system, It is possible to match the power balance of the system. However, since the steering position actuator and the seat actuator are rarely used at the same time, they may be arranged together in the same system. Further, it is more preferable to arrange or wire the DC motors that operate simultaneously in the same phase, and to arrange or wire them so that the energization direction becomes the same when they operate simultaneously.

(12th embodiment)
In the twelfth embodiment shown in FIG. 48, the first inverter 601 and the second inverter 602 are connected to separate first power supply Bt1 and second power supply Bt2. The second inverter 602 is connected to the positive electrode of the second power source Bt2 via the high potential line BH2, and is connected to the negative electrode of the second power source Bt2 via the low potential line BL2. Power supply relays P1r/R and P2r/R and capacitors C1 and C2 are individually provided at the input portions of the inverters 601 and 602, respectively. Thus, the twelfth embodiment is a so-called "complete two-system" redundant configuration. In the twelfth embodiment, for example, when one power supply fails, the three-phase motor 800 can be driven in a single system drive mode using only the other normal power supply.

Two DC motors 710 and 720 are connected to the U1 phase of the first system, and two DC motors 750 and 760 are connected to the U2 phase of the second system. Both positive and negative DC motor relays MU1r/R and MU2r/R are connected to the first system U1-phase DC motors 710 and 720, and the second system U2-phase DC motors 750 and 760 are connected to both positive and negative directions. DC motor relays MU5r/R and MU6r/R are connected. Similarly to the DC motors 710, 720 connected to the U1 phase of the first system, counter electromotive voltages generated in the respective DC motors 750, 760 connected to the U2 phase of the second system are denoted by E5 and E6.

The application of each DC motor 750, 760 may be selected as appropriate. For example, the DC motors 750 and 760 may be seat actuators, steering wheel storage actuators, or steering lock actuators. Alternatively, a steering position actuator such as a tilt or telescopic actuator may be provided as the DC motors 750 and 760 on the second system side.

[effect]
(1) The ECU 10 of the present embodiment (here, the symbols of the first embodiment are used) operates the inverter switching elements IU1H/L, IV1H/L, and IW1H/L to drive the three-phase motor 800. Meanwhile, by operating the DC motor switches MU1H/L and MU2H/L, a plurality of DC motors 710 and 720 connected to the same single phase of the three-phase winding set 801 can be driven simultaneously.

In addition, in the configuration in which the two DC motors 710 and 720 are connected to the same single phase current path of the set of three-phase winding sets 801 as in the first embodiment, the minimum number of DC motors is four. It is sufficient if there are switches MU1H, MU1L, MU2H, and MU2L. Therefore, the number of switches can be reduced as compared with the prior art of Patent Document 1.

(2) The control unit 30 switches on and off the high-potential-side and low-potential-side DC motor switches according to the direction in which the DC motor is energized, and raises or lowers the neutral point voltage Vn1 of the three-phase motor 800. Operate to lower. Thereby, the controller 30 can appropriately control the energization of the specific DC motor.

(3) In the second embodiment, two DC motors are connected to each of the two phases of the three-phase winding set 801, for a total of four DC motors. In the twelfth embodiment, two DC motors are connected to each phase of two sets of three-phase winding sets 801 and 802, for a total of four DC motors. In other words, a total of three or more DC motors are connected in each case.

In addition, a configuration in which three or more DC motors are connected to one phase of one set of three-phase winding sets, two or more DC motors are connected to one phase of one set of three-phase winding sets, and A total of three or more DC motors can be connected in a configuration in which one DC motor is connected to another phase. Also, when a plurality of DC motors are connected to the same phase, the plurality of DC motors can be energized at the same time. In this way, by connecting a total of three or more DC motors to the phase current paths of the three-phase winding sets, the range of applications for simultaneous driving of multiple actuators is further expanded.

(4) The ECU 10 of this embodiment has a plurality of current sensors SAU1, SAV1, and SAW1 that detect the current flowing through each phase of the inverter 601 . The control unit 30 calculates the current flowing through the specific DC motor from the detection values of the non-specific phase and specific phase current sensors and the estimated current value of the specific phase based on Kirchhoff's law. Thereby, the controller 30 can appropriately control the energization of the specific DC motor.

(5) The ECU 10 of the present embodiment is suitably applied as a device that controls driving of the steering assist motor of the EPS system 901 or the reaction force motor of the SBW system 902 as the three-phase motor 800 . In that case, it is effective to use a steering position system actuator for varying the steering position, specifically the tilt actuator 710 or the telescopic actuator 720, as the DC motor.

(Other embodiments)
(a) As in the third and fourth patterns of the phase voltage and DC motor terminal voltage calculation processing, the DC motor terminal voltages Vm1 and Vm2 are only for ON/OFF switching of the DC motor switches MU1H/L and MU2H/L. , and the voltage value should be variable. Then, on the premise that high-speed switching operation is not performed, a transistor or a mechanical relay that switches slowly may be used. In addition, the inverter switching element connected to the DC motor may carry a larger current than the other inverter switching elements. It may be placed in a place where heat is not concentrated or in a place with good heat dissipation.

(b) For the DC motor switches MU1H/L and MU2H/L, switches having current capacities equal to or greater than those of the inverter switching elements IU1H/L, IV1H/L and IW1H/L may be used. Also, the DC motor switch side power relay Pdr/R may use a switch having a current capacity equal to or greater than that of the inverter side power relay P1r/R. In addition, the dead time for preventing the simultaneous ON of each upper and lower switch may be set individually according to each switch and the magnitude of the flowing current, and the voltage for compensating for the dead time is the set dead time Each up/down switch may be individually set according to the amount of current that flows. Polarity determination of the compensation voltage for the dead time is determined by the sign of the current flowing through each upper and lower switch.

(c) For the DC motors 710 and 720 of the third embodiment and the like, assuming a terminal ground fault, only the positive direction DC motor relays MU1r and MU2r may be provided without providing the negative direction DC motor relays MU1R and MU2R. Also, the direction of series connection of the forward DC motor relays MU1r, MU2r and the negative direction DC motor relays MU1R, MU2R may be the direction in which the drain terminals of the MOSFETs are adjacent to each other, contrary to FIG.

(d) The three-phase motor relays MmU1, MmV1, MmW1 or DC motor relays MU1r/R, MU2r/R may be mechanical relays or bidirectional relays. If the three-phase motor relays MmU1, MmV1, and MmW1 are mechanical relays or bidirectional relays, they may be provided in two phases. In FIG. 7, the source terminals of the three-phase motor relays MmU1, MmV1 and MmW1 face the inverter, but the drain terminals of the three-phase motor relays MmU1, MmV1 and MmW1 may face the inverter.

(e) The current sensor is not limited to detecting the current flowing between the lower arm element of the inverter and the low potential line BL1, and may directly detect the phase current.

(f) In the eleventh and twelfth embodiments, the positive direction power relay, the negative direction power relay and the noise prevention element corresponding to the inverter 601 of the first system and the DC motor switches MU1H/L and MU2H/L are the third embodiment. It is configured according to the form. On the other hand, the configuration of each system may be configured according to the fourth to eighth embodiments. The two systems may have the same configuration or may have different configurations.

(g) As shown in FIG. 49, the DC motor switch may be composed of double-throw switches MU1DT and MU2DT. The double-throw switches MU1DT and MU2DT can switch the connection between the DC motor terminals M1 and M2 and the high-potential side contact and the low-potential side contact.

(h) The two direct-current motors are not limited to independent forms, and may be stepping motors having two-phase windings.

(i) The number of phases of the multiphase rotating machine is not limited to three, but may be two, or four or more, that is, generalized N phases (N is an integer equal to or greater than 2). Also, the polyphase rotating machine may include three or more polyphase winding sets.

(j) The rotating machine control device of the present invention is not limited to a steering assist motor or a reaction force motor in a steering system of a vehicle, and a DC motor for a steering position system actuator, a seat system actuator, etc. It can be applied as various rotating machine control devices that use a motor together. Further, the steering assist motor or the reaction motor may not be of the electromechanical integrated type, but may be of the electromechanical separate type in which the motor main body and the ECU are connected by a harness.

The structure of the present invention is more effective in motors for vehicles in which various motors are arranged close to each other. It can be applied to a combination of a wiper motor, a window motor, a side mirror motor, an electric water pump motor and an electric fan motor, and the like.

The present invention is not limited to such embodiments, and can be embodied in various forms without departing from the scope of the invention.

The controller and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by the computer program. may be Alternatively, the controls and techniques described in this disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control units and techniques described in this disclosure can be implemented by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. It may also be implemented by one or more dedicated computers configured. The computer program may also be stored as computer-executable instructions on a computer-readable non-transitional tangible recording medium.

10...ECU (rotating machine control device), 30...control section,
601 ... Inverter (polyphase power converter),
710: DC motor, tilt actuator (DC rotating machine),
720: DC motor, telescopic actuator (DC rotating machine),
730: DC motor, first sheet motor (DC rotating machine),
740 ... DC motor, second sheet motor (DC rotating machine),
800... three-phase motor (polyphase rotating machine),
801... three-phase winding set (polyphase winding set), 811-813... each phase winding,
Bt1: power supply,
IU1H/L, IV1H/L, IW1H/L ... inverter switching elements,
MU1H/L, MU2H/L, MV3H/L, MV4H/L -- DC motor switches (DC rotary machine switches).

Claims (25)

One or more multiphase rotating machines (800) including one or more sets of multiphase winding sets (801), and one end of one or more phase current paths of at least one set of the multiphase winding sets A rotating machine control device capable of driving a plurality of DC rotating machines (710, 720, 730, 740) to which a first terminal (T1) is connected,
the first terminals of any two or more of the plurality of DC rotating machines are connected to the same single-phase current path of the multiphase winding set,
A plurality of bridge-connected inverter switching elements (IU1H/L, IV1H/L, IW1H/L) are connected to the positive and negative electrodes of a power source (Bt1) via a high potential line (BH1) and a low potential line (BL1), respectively. ) converts the DC power of the power supply into multiphase AC power and applies a voltage to each phase winding (811, 812, 813) of the multiphase winding set. (601) and
A high potential side connected in series via DC motor terminals (M1, M2, M3, M4) connected to a second terminal (T2), which is the end opposite to the first terminal of the DC rotating machine and a leg consisting of a switch on the low potential side, and switches for DC rotating machines (MU1H/L, MU2H/L, MU2H/L, MV3H/L, MV4H/L) and
a control unit (30) that operates the inverter switching element and the DC rotary machine switch;
with
The control unit
When energizing in the positive direction from the first terminal of the DC rotating machine to the second terminal, the switch for the DC rotating machine on the low potential side connected to the second terminal is turned on, or the second terminal is turned on. switching the DC rotating machine switches on the low potential side and the high potential side connected to , so that the voltage of the second terminal is lower than the voltage of the first terminal, and Operate to increase the sex point voltage (Vn1),
When energizing in the negative direction from the second terminal of the DC rotating machine to the first terminal, the switch for the DC rotating machine on the high potential side connected to the second terminal is turned on, or the second terminal is turned on. switching the DC rotating machine switches on the low potential side and the high potential side connected to the second terminal so that the voltage of the second terminal is higher than the voltage of the first terminal, and A rotating machine control device that operates to lower the sex point voltage . 2. The rotating machine control device according to claim 1 , wherein the control section can adjust the neutral point voltage according to the voltage applied to the multiphase winding set. The rotating machine control device according to claim 1 or 2 , wherein the control unit switches between driving and stopping the DC rotating machine by manipulating the neutral point voltage based on a predetermined condition. One or more multiphase rotating machines (800) including one or more sets of multiphase winding sets (801), and one end of one or more phase current paths of at least one set of the multiphase winding sets A rotating machine control device capable of driving a plurality of DC rotating machines (710, 720, 730, 740) to which a first terminal (T1) is connected,
the first terminals of any two or more of the plurality of DC rotating machines are connected to the same single-phase current path of the multiphase winding set,
A plurality of bridge-connected inverter switching elements (IU1H/L, IV1H/L, IW1H/L) are connected to the positive and negative electrodes of a power source (Bt1) via a high potential line (BH1) and a low potential line (BL1), respectively. ) converts the DC power of the power supply into multiphase AC power and applies a voltage to each phase winding (811, 812, 813) of the multiphase winding set. (601) and
A high potential side connected in series via DC motor terminals (M1, M2, M3, M4) connected to a second terminal (T2), which is the end opposite to the first terminal of the DC rotating machine and a leg consisting of a switch on the low potential side, and switches for DC rotating machines (MU1H/L, MU2H/L, MU2H/L, MV3H/L, MV4H/L) and
a control unit (30) that operates the inverter switching element and the DC rotary machine switch;
a plurality of current sensors (SAU1, SAV1, SAW1) that detect a current flowing through each phase of the polyphase power converter;
with
One of the plurality of DC rotating machines selected to be energized, or two or more of the DC rotating machines connected to the same phase are defined as a specific DC rotating machine, and the specific DC rotating machine is connected. If the phase is defined as a specific phase and the phase other than the specific phase is defined as a non-specific phase,
When the control unit energizes the specific DC rotating machine,
calculating a current value flowing through the specific phase as an estimated current value according to Kirchhoff's law from the current value detected by the current sensor of the non-specific phase;
A rotary machine control device that calculates a current flowing through the specific DC rotary machine from the estimated current value and the current value detected by the current sensor of the specific phase. 5. The rotating machine control device according to claim 4 , wherein the current sensor is installed between the low-potential-side switching element of each phase of the polyphase power converter and the low-potential line. One or more multiphase rotating machines (800) including one or more sets of multiphase winding sets (801), and one end of one or more phase current paths of at least one set of the multiphase winding sets A rotating machine control device capable of driving a plurality of DC rotating machines (710, 720, 730, 740) to which a first terminal (T1) is connected,
the first terminals of any two or more of the plurality of DC rotating machines are connected to the same single-phase current path of the multiphase winding set,
A plurality of bridge-connected inverter switching elements (IU1H/L, IV1H/L, IW1H/L) are connected to the positive and negative electrodes of a power source (Bt1) via a high potential line (BH1) and a low potential line (BL1), respectively. ) converts the DC power of the power supply into multiphase AC power and applies a voltage to each phase winding (811, 812, 813) of the multiphase winding set. (601) and
A high potential side connected in series via DC motor terminals (M1, M2, M3, M4) connected to a second terminal (T2), which is the end opposite to the first terminal of the DC rotating machine and a leg consisting of a switch on the low potential side, and switches for DC rotating machines (MU1H/L, MU2H/L, MU2H/L, MV3H/L, MV4H/L) and
a control unit (30) that operates the inverter switching element and the DC rotary machine switch;
with
The control unit detects an abnormality in the polyphase power converter or the polyphase rotating machine, and switches a fail-safe threshold value in the abnormality detection depending on whether the DC rotating machine is driven or not driven. machine controller. The rotating machine control device according to any one of claims 1 to 6 , wherein the number of the DC rotating machines is the same as the number of legs constituting the DC rotating machine switch. When simultaneously energizing a plurality of DC rotating machines connected to the same single-phase phase current path of the multiphase winding set, the control unit:
For a DC rotating machine that is energized in the positive direction from the first terminal to the second terminal of the DC rotating machine, the switch for the DC rotating machine on the low potential side connected to the second terminal is turned on. Alternatively, switching the DC rotating machine switches on the low potential side and the high potential side connected to the second terminal so that the voltage of the second terminal becomes lower than the voltage of the first terminal,
For a DC rotating machine that is energized in a negative direction from the second terminal of the DC rotating machine to the first terminal, the switch for the DC rotating machine on the high potential side connected to the second terminal is turned on. Alternatively, switching the DC rotating machine switches on the low potential side and the high potential side connected to the second terminal so that the voltage of the second terminal is higher than the voltage of the first terminal,
The rotating machine control device according to any one of claims 1 to 7 . DC rotary machine relays (MU1r/R, MU2r) on the DC rotary machine side of the branch points (Ju, Jv) to the DC rotary machine in the phase current path from the polyphase power converter to the polyphase rotary machine. / R ) is provided. A multiphase rotary machine relay (MmU1, MmV1, MmW1) is provided in one or more phases between the multiphase power converter and the multiphase winding set,
In the phase to which the DC rotating machine is connected, the polyphase rotating machine side of the branch point (Ju, Jv) to the DC rotating machine in the phase current path from the polyphase power converter to the polyphase rotating machine The rotary machine control device according to any one of claims 1 to 9 , wherein the polyphase rotary machine relay is provided in the. The rotary machine control device according to any one of claims 1 to 10 , wherein the polyphase power converter and the DC rotary machine switch are connected to individual power sources (Bt1, Btd). The rotary machine control device according to any one of claims 1 to 11 , wherein the DC rotary machine switch has a current capacity smaller than that of the inverter switching element. A negative-direction power relay (P1R) capable of interrupting power supply from the power supply when the electrodes of the power supply are connected in a direction opposite to the normal direction is provided in the multiphase power converter and the switch for the DC rotating machine. The rotary machine control device according to any one of claims 1 to 12 , wherein the rotating machine control device is provided in common with respect to the A positive direction power relay (P1r) capable of interrupting power supply from the power supply when the electrodes of the power supply are connected in the normal direction is further common to the polyphase power converter and the switch for the DC rotating machine. 14. The rotary machine control device according to claim 13 , provided in the . Power supply relays (P1r, P1R, Pdr, PdR) capable of interrupting power supply from the power supply are provided individually for the polyphase power converter and the DC rotating machine switch,
The rotating machine control device according to any one of claims 1 to 12 , wherein the power relay on the DC rotating machine switch side has a smaller current capacity than the power relay on the polyphase power converter side. The rotation according to any one of claims 1 to 15 , wherein a noise prevention element (L1, C1) functioning as a noise filter is provided in common for the polyphase power converter and the DC rotating machine switch. machine controller. Noise prevention elements (L1, C1, Ld, Cd ) functioning as noise filters are individually provided for the polyphase power converter and the switch for the DC rotary machine. The rotating machine control device according to . The rotating machine control device according to any one of claims 1 to 17 , wherein the polyphase rotating machine is a three-phase double-winding rotating machine in which two sets of three-phase winding sets are coaxially provided. 19. The rotary machine control device according to claim 18 , wherein the DC rotary machine is connected to the same number of two sets of three-phase winding sets. 19. The rotary machine control device according to claim 18 , wherein the DC rotary machine is connected to two sets of three-phase winding sets in different numbers, or is connected to only one of the three-phase winding sets. 19. The rotary machine control device according to claim 18 , wherein the polyphase power converter or the DC rotary machine switch has two systems. A rotating machine control device according to any one of claims 1 to 21 , comprising a plurality of said polyphase power converters connected to individual power supplies (Bt1, Bt2). The control unit
When the DC rotating machine is energized and the polyphase rotating machine is not energized,
turning on the inverter switching element on the high potential side of the phase connected to the energized DC rotating machine, and turning off the inverter switching element on the low potential side;
Turning off the DC rotating machine switch on the high potential side and turning on the DC rotating machine switch on the low potential side, or turning on the DC rotating machine switch on the low potential side and the high potential side connected to the second terminal is switched so that the voltage of the second terminal is lower than the voltage of the first terminal,
or
turning off the inverter switching element on the high potential side of the phase connected to the energized DC rotating machine, turning on the inverter switching element on the low potential side; and
The DC rotating machine switch on the high potential side is turned on, the DC rotating machine switch on the low potential side is turned off, or the DC rotating machine switch on the low potential side and the high potential side connected to the second terminal is turned off. is switched so that the voltage of the second terminal is higher than the voltage of the first terminal,
or
switching the inverter switching elements of each phase connected to the energized DC rotating machine so that the terminal voltage of each phase becomes the same voltage;
When energizing in the positive direction from the first terminal of the DC rotating machine to the second terminal, the switch for the DC rotating machine on the low potential side connected to the second terminal is turned on, or the second terminal is turned on. Switching the DC rotating machine switches on the low potential side and the high potential side connected to the second terminal so that the voltage of the second terminal is lower than the voltage of the first terminal,
When energizing in the negative direction from the second terminal of the DC rotating machine to the first terminal, the switch for the DC rotating machine on the high potential side connected to the second terminal is turned on, or the second terminal is turned on. Switching the DC rotating machine switches on the low potential side and the high potential side connected to the second terminal so that the voltage of the second terminal is higher than the voltage of the first terminal,
The rotating machine control device according to any one of claims 1 to 22 . The polyphase rotating machine is a rotating machine for steering assist torque output of an electric power steering system (901) or for reaction torque output of a steer-by-wire system ( 902 ). The rotating machine control device according to . 25. The rotary machine control device according to claim 24 , wherein the DC rotary machine includes a steering position system actuator (730, 740) for varying a steering position.

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