JP5152573B2 - Control device for rotating electrical machine - Google Patents

Description

  The present invention controls a rotating electrical machine comprising: a voltage converting unit that converts the output of a DC power source to generate a driving voltage; and a frequency converting unit that controls the rotating electrical machine and converts the driving voltage into an AC voltage. Relates to the device.

  In recent years, hybrid vehicles and electric vehicles that use motors as power sources have been put into practical use as vehicles effective in suppressing global warming, and development has been promoted to achieve higher output, lower fuel consumption, and lower costs. It has been. However, there is a trade-off relationship described below between these high output, low fuel consumption, and low cost.

  In order to achieve high output, it is effective to increase the output torque of the motor, and one means for this is to increase the drive voltage for driving the motor. In order to increase the drive voltage, the boost ratio in the boost circuit that generates the drive voltage must be increased. Therefore, it is necessary to select a component having excellent withstand voltage characteristics for a booster circuit or an inverter that converts a boosted voltage generated by the booster circuit into an AC voltage. As a result, the cost related to the components increases. Further, when the boosting ratio in the booster circuit is increased, the conversion efficiency is deteriorated and the surge voltage generated in components used in the booster circuit and the inverter is increased. In order to reduce such a surge voltage, it is necessary to slow down the switching speed. However, when the switching speed is slowed, the switching loss increases. Therefore, fuel consumption is deteriorated.

  Therefore, as one of means for realizing low fuel consumption, the switching loss is reduced. In order to reduce the switching loss, it is preferable to increase the switching speed. However, when the switching speed is increased, surge voltage generated in components used in the booster circuit and the inverter increases. For this reason, it is necessary to reduce the boost ratio in the booster circuit. As a result, the output torque of the motor becomes small and high output cannot be realized. Regarding the inverter for driving a motor, several techniques for improving such a problem have already been disclosed (for example, Patent Documents 1 and 2).

  The power supply device described in Patent Document 1 relates to a technique that achieves both reduction of surge voltage and loss that occur during switching of a switching element included in an inverter that drives a three-phase motor. In this power supply device, the power supply voltage supplied to the switching element is changed according to the temperature of the switching element so that the surge voltage does not exceed the withstand voltage characteristic that changes according to the temperature of the switching element. Therefore, since the resistance value of the gate resistance can be determined based on the withstand voltage characteristic on the normal temperature side having high withstand voltage characteristics, the resistance value of the gate resistance can be reduced. For this reason, the switching speed can be increased.

  Moreover, the control apparatus of the electric vehicle of patent document 2 is related with the technique which reduces switching loss, suppressing the surge voltage which arises in IGBT with which the drive inverter of a motor is provided below to an allowable surge withstand pressure | voltage. This control device changes the gate resistance according to the temperature based on the temperature of the IGBT detected by the IGBT temperature detecting means. The resistance value of the gate resistance is changed according to the temperature so as to be equal to or lower than an allowable surge voltage that changes according to the temperature of the IGBT. Therefore, since the gate resistance suitable for the temperature of the IGBT is set, the switching loss can be reduced according to the temperature.

JP 2007-143293 A JP 2001-169407 A

As described above, the techniques disclosed in Patent Documents 1 and 2 are intended only for the inverter for driving the motor. For this reason, when a boost converter and an inverter are provided, the following problems may occur.
In the power supply device described in Patent Document 1, since the power supply voltage is changed according to the temperature of the switching element included in the inverter, the surge voltage may be increased depending on the temperature of the switching element of the boost converter that generates the power supply voltage. May exceed the withstand voltage of the switching element, and the switching element may deteriorate and be damaged.

  In the control device described in Patent Document 2, the switching speed in the drive inverter can be optimized by changing the switching speed in accordance with the temperature of the IGBT included in the drive inverter. However, when a booster circuit is provided in front of the drive inverter, the switching speed of a switching element such as an IGBT provided in the booster circuit cannot be changed. Therefore, it is not easy to improve fuel efficiency by improving the efficiency of the entire control device.

  The present invention has been made in view of the above problems, and an object thereof is to realize high output in a control device for a rotating electrical machine including a voltage converter such as a boost converter and a frequency converter such as an inverter. In addition, an object of the present invention is to provide a control device for a rotating electrical machine that can reduce costs.

In order to achieve the above object, a characteristic configuration of a control device for a rotating electrical machine according to the present invention includes: a voltage conversion unit that converts a DC power supply output to generate a driving voltage; and the rotating electrical machine as a control target. A frequency conversion unit for converting to an AC voltage, and based on the element temperature of the first switching element included in the voltage conversion unit, the limit value of the drive voltage in the voltage conversion unit is determined as the first limit value Based on the first limit value determination unit and the element temperature of the second switching element included in the frequency conversion unit, the second limit value determination that determines the limit value of the drive voltage in the frequency conversion unit as the second limit value parts and, e Bei common limit value determining section, the determining the lower limit value of the first limit value and the second limit value as the common limit value, the first limit value and the second limit value High The switching speed of the voltage converter or the switching element, wherein the frequency conversion unit has a limiting value lies in accelerating according to a difference between the limit value and the common limit.

With such a characteristic configuration, the voltage conversion unit generates the first switching element included in the voltage conversion unit and the second switching element included in the frequency conversion unit based on the element breakdown voltage determined according to the element temperature. By determining the limit value of the driving voltage, the voltage applied to each switching element exceeds the device withstand voltage even when the withstand voltage of the first switching element and the second switching element changes according to the respective element temperatures. It can be controlled so that there is no. For this reason, since the drive voltage according to the element temperature of both the 1st switching element and the 2nd switching element which changes according to the driving | running state of a control apparatus is supplied to each switching element, the voltage added to each switching element is element withstand voltage | voltage. A high voltage can be supplied to the switching element within a range not exceeding. Therefore, high output of the rotating electrical machine can be achieved. Furthermore, since it is not necessary to set the element withstand voltage based on the situation where the temperature condition is bad, that is, the condition where the element temperature is very low, it is not necessary to use a switching element having an excellent withstand voltage characteristic, and the cost can be reduced. It becomes possible.
In addition, with such a characteristic configuration, the switching speed of the first switching element can be increased according to the difference between the common limit value and the first limit value. Alternatively, the switching speed of the second switching element can be increased according to the difference between the common limit value and the second limit value. Therefore, the switching loss of the switching element can be reduced and the efficiency can be further increased. Further, according to this feature configuration, the switching speed is calculated based on only the first limit value, the second limit value, and the common limit value determined based on the element temperature of each switching element. It is possible to reduce the processing load related to the above.
In the present application, the “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator functioning as both a motor and a generator as necessary.

  The first limit value is determined by subtracting an estimated value of a surge voltage generated according to a current flowing through the first switching element from an element withstand voltage determined according to an element temperature of the first switching element, The second limit value is preferably determined by subtracting an estimated value of a surge voltage generated according to a current flowing through the second switching element from an element breakdown voltage determined according to an element temperature of the second switching element. .

  With such a configuration, the first limit value in the voltage conversion unit is determined from the element withstand voltage of the first switching element and the estimated value of the surge voltage estimated from the current flowing through the first switching element. The element withstand voltage of the first switching element can be surely not exceeded. In addition, since the second limit value in the frequency conversion unit is determined from the element breakdown voltage of the second switching element and the estimated value of the surge voltage estimated from the current flowing through the second switching element, the second switching value is surely set. It is possible not to exceed the element breakdown voltage of the element. Therefore, the limit value can be easily determined according to the energization state of each switching element.

  The drive voltage is determined according to a target torque and a rotation speed of the rotating electrical machine, and the voltage conversion unit preferably limits the drive voltage to the common limit value or less.

  With such a configuration, it is possible to generate a drive voltage according to the target torque and the rotation speed within a range not exceeding the common limit value. For this reason, it becomes possible to drive the rotating electrical machine appropriately without exceeding the element breakdown voltage.

  For example, the switching speed of the switching element can be changed by changing the voltage applied to the control resistor connected to the control terminal of the switching element or the resistance value of the control resistor by the driver driving the switching element. Is possible.

  With such a configuration, the switching speed of the switching element can be easily changed.

  Further, the rotating electrical machine is a first rotating electrical machine, and the frequency converter that controls the first rotating electrical machine is a first frequency converting unit, in addition to the first rotating electrical machine, a second A second frequency converter that converts the drive voltage into an AC voltage, and a third switching element included in the second frequency converter. A third limit value determining unit that determines a limit value of the drive voltage in the second frequency conversion unit as a third limit value based on an element temperature, and the common limit value determining unit includes the first limit value determining unit, It is preferable to determine the lowest limit value among the one limit value, the second limit value, and the third limit value as the common limit value.

  Thus, even if it is the structure provided with two rotary electric machines, if it is a control apparatus of this rotary electric machine, the effect similar to the above can be acquired.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a case where a control device 100 (hereinafter referred to as a control device) for a rotating electrical machine according to the present invention is applied to a hybrid vehicle will be described as an example. FIG. 1 is a schematic diagram schematically showing the configuration of the control device 100 according to the present embodiment. This control device 100 is connected to a high-voltage (for example, 210V) battery B1, a low-voltage (for example, 12V) battery B2, a first rotating electrical machine MG1, and a second rotating electrical machine MG2 provided in the hybrid vehicle. The The control device 100 is conventionally used when the first rotating electrical machine MG1 and the second rotating electrical machine MG2 are rotationally driven using the output of the high-voltage battery B1 and the output of the low-voltage battery B2. The first rotary electric machine MG1 and the second rotary electric machine MG2 are provided with a function of rotating and driving with high output and high efficiency without changing inexpensive parts. Hereinafter, the configuration of each unit of the control device 100 will be described.

  The high-voltage battery B1 and the low-voltage battery B2 are configured to output a predetermined voltage and current by connecting a plurality of battery cells of about several volts in series and parallel. The high-voltage battery B1 is used as a drive source for driving the first rotating electrical machine MG1 and the second rotating electrical machine MG2, and outputs a voltage of about 210V, for example. The output of the battery B1 is also used as a power source for electrical components (not shown) with relatively large power consumption such as an air conditioner provided in the hybrid vehicle. On the other hand, the low-voltage battery B2 is used as a power source for the driver 3 (described later), and outputs a voltage of about 12V, for example. The output of the battery B2 is also used as a power source for electrical components (not shown) with relatively low power consumption such as a microcomputer provided in the hybrid vehicle.

  The first rotating electrical machine MG1 and the second rotating electrical machine MG2 each have a function as a motor (electric motor) that receives the supply of electric power and generates rotational power, and a generator (electric power generation) that receives the supply of rotational power and generates electric power. Function). Therefore, in the following description, reference numerals MG1 and MG2 may be omitted when it is not particularly necessary to specify any rotating electrical machine. The electric power supplied when the rotating electrical machine functions as a motor is generated by the other rotating electrical machine functioning as the drive voltage generated by the voltage conversion unit 1 or the generator based on the output of the high-voltage battery B1 described above. Electric energy is used (details will be described later). Further, as the rotational power supplied when the rotating electrical machine functions as a generator, the rotational driving force generated by the engine provided in the hybrid vehicle or the rotational driving force transmitted from the wheel side during the inertia traveling of the vehicle is used.

  The control device 100 mainly includes a voltage conversion unit 1, a frequency conversion unit 2, a driver 3, a driver power supply unit 4, an element temperature detection unit 5, a current detection unit 6, a rotation angle detection unit 7, a TCU (trans-axle control). unit) 10 functional units. As described above, the control device 100 drives the first rotating electrical machine MG1 and the second rotating electrical machine MG2 to rotate.

  The first rotating electrical machine MG1 mainly functions as a motor that assists the driving force for traveling the hybrid vehicle. Further, at the time of deceleration of the hybrid vehicle, the first rotating electrical machine MG1 functions as a generator that regenerates the inertial force of the hybrid vehicle as electric energy.

  On the other hand, the second rotating electrical machine MG2 functions as a generator that generates power mainly by the rotational driving force from the engine, and charges the battery B1 or supplies electric power for driving the first rotating electrical machine MG1. However, when the hybrid vehicle travels at a high speed, the second rotating electrical machine MG2 may function as a motor. Such operations of the first rotating electrical machine MG1 and the second rotating electrical machine MG2 are controlled by the TCU 10.

  The rotary electric machine MG1 and the rotary electric machine MG2 include a rotor (not shown) including a permanent magnet and a stator that generates a magnetic field for applying a rotational force to the rotor. This stator includes three-phase stator coils s1u, s1v, s1w, and s2u, s2v, s2w composed of a U phase, a V phase, and a W phase. One end of each stator coil is connected in common at an electrically neutral point and Y-connected. The other end of each stator coil is connected to a frequency converter 2 described later.

  The voltage converter 1 converts the output of the DC power source to generate a drive voltage. The DC power source corresponds to the above-described high-voltage battery B1. Therefore, the output of the DC power supply corresponds to the voltage output from the battery B1. The driving voltage indicates a voltage supplied to the first rotating electrical machine MG1 and the second rotating electrical machine MG2 in order to rotationally drive the first rotating electrical machine MG1 and the second rotating electrical machine MG2. Therefore, the voltage converter 1 converts the output of the battery B1 to generate a drive voltage for rotationally driving the first rotating electrical machine MG1 and the second rotating electrical machine MG2. This drive voltage is determined according to the target torque and the rotational speed. The target torque is a torque that is required to be output by the rotating electrical machine in order for the hybrid vehicle to travel appropriately in accordance with the traveling state and the driver's operation (accelerator operation, brake operation, etc.). The rotation speed is the rotation speed detected by the rotation angle detector 7 such as a resolver.

  Here, the voltage conversion unit 1 includes a first smoothing capacitor 1a, a coil 1b, a pair of upper and lower switching elements 1c and 1d, a pair of upper and lower diodes 1e and 1f, a discharging resistor 1g, and a second smoothing capacitor 1h. Consists of The voltage conversion unit 1 in this embodiment functions as a boost converter when the rotating electrical machine functions as a motor. Therefore, the conversion of the output performed by the voltage conversion unit 1 refers to a boost conversion in which the voltage output from the battery B1 is set to a voltage higher than the voltage. Although details will be described later, the voltage conversion unit 1 functions as a step-down converter when the rotating electrical machine functions as a generator, and is suitable for regenerating electric energy (voltage) generated by the rotating electrical machine to the battery B1. It is also possible to perform step-down conversion that steps down the voltage.

  Here, as the switching elements 1c and 1d included in the voltage conversion unit 1, an IGBT (Insulated Gate Bipolar Transistor), a MOS-FET (Metal Oxide Semiconductor-Field Effect Transistor), or a bipolar transistor can be used. In the following description, unless otherwise specified, the switching elements 1c and 1d are described as IGBTs 1c and 1d.

  When the voltage converter 1 functions as a boost converter, the voltage output from the battery B1 is boosted to generate a drive voltage. In this case, the first smoothing capacitor 1a, the coil 1b, the IGBT 1d, the diode 1e, and the second smoothing capacitor 1h are mainly used.

  The first smoothing capacitor 1a removes a ripple component superimposed on the output of the battery B1. The coil 1b stores energy according to the ON operation of the IGBT 1d, and releases the stored energy according to the OFF operation. The IGBT 1d is ON / OFF controlled to store and release the energy of the coil 1b as described above. The IGBT 1d conducts between the collector and the emitter during the ON operation, and a collector current flows. When this collector current is flowing, energy is stored in the coil 1b. This ON / OFF control is performed by PWM (Pulse Width Modulation) control by the TCU 10 via a driver 3 (described later).

  When the IGBT 1d is turned off, the diode 1e superimposes the energy stored in the coil on the output from the battery B1, and causes a current to flow from the anode side to the cathode side. The second smoothing capacitor 1h stores energy by the current flowing through the diode 1e and performs smoothing. Therefore, a boosted voltage boosted from the voltage output from the battery B1 can be output from the power supply line 20 connected to one end of the second capacitor 1h. The discharging resistor 1g functions as a discharging unit that discharges the energy charged in the second smoothing capacitor 1h when the voltage converter 1 and the rotating electrical machine are stopped. As described above, the voltage conversion unit 1 converts the output of the battery B1 to generate a boosted voltage suitable for the drive voltage.

  Here, in PWM control when the voltage conversion unit 1 functions as a boost converter, the IGBT 1d is DUTY-controlled. This DUTY control is performed according to the step-up ratio, which is the ratio between the input voltage and the output voltage, and the output load. In the present embodiment, the input voltage corresponds to the output of the battery B1, and the output voltage corresponds to the drive voltage supplied to the rotating electrical machine. The step-up ratio is a ratio obtained by dividing the output voltage by the input voltage. For example, when the difference between the input voltage and the output voltage is small, the boost ratio is close to 1. In such a case, the on-duty of the IGBT 1d becomes small. On the other hand, when the difference between the input voltage and the output voltage is large, the boost ratio becomes large. In such a case, the on-duty of the IGBT 1d increases. Therefore, when the step-up ratio is greater than 1, the collector current of the IGBT 1d increases.

  The DUTY control is also performed according to the output load of the voltage conversion unit 1. The output load is a load connected to the output side of the voltage conversion unit 1. In the case of this embodiment, a rotary electric machine corresponds. This load fluctuates according to a change in current flowing in a stator coil provided in the rotating electrical machine. That is, when the current flowing through the stator coil is large, this corresponds to an increase in the output load of the voltage generator 1, and the on-duty of the IGBT 1d increases. On the other hand, when the current flowing through the stator coil is small, this corresponds to a reduction in the output load of the voltage generator 1, and the on-duty of the IGBT 1d is reduced. Therefore, when the output load of the voltage conversion unit 1 becomes heavy, the collector current of the IGBT 1d increases.

  Thus, the collector current of the IGBT 1d increases according to the boost ratio and the output load. Here, it is known that the IGBT generates a collector loss corresponding to the product of the collector-emitter voltage and the collector current, and the IGBT generates heat according to the collector loss. Therefore, as described above, when the collector loss of the IGBT 1d increases according to the boost ratio and the output load, the element temperature of the IGBT 1d increases. The collector loss includes not only the steady state loss of the IGBT but also the switching loss related to the turn-on and turn-off of the IGBT (described later).

  When the voltage conversion unit 1 functions as a step-down converter, the energy stored in the second smoothing capacitor 1h is stepped down to a voltage suitable for charging the battery B1 according to the rotation of the rotating electrical machine. In this case, the first smoothing capacitor 1a, the coil 1b, the switching element 1c, the diode 1f, and the second smoothing capacitor 1h are mainly used.

  The second smoothing capacitor 1h charges electrical energy generated by the generator function of the rotating electrical machine. The coil 1b stores energy according to the ON operation of the switching element 1c, and releases the stored energy according to the OFF operation. The IGBT 1c is ON / OFF controlled in order to store and release energy in the coil 1b as described above. The IGBT 1c conducts between the collector and the emitter during the ON operation, and a collector current flows. When this collector current is flowing, energy is stored in the coil 1b. Also in this case, the ON / OFF control is PWM-controlled by the TCU 10 via the driver 3 as in the case where the voltage conversion unit 1 functions as a boost converter.

  The diode 1f functions as a commutation diode that commutates the current corresponding to the energy released from the coil 1b during the OFF operation of the IGBT 1c via the first smoothing capacitor 1a. The first smoothing capacitor 1a stores energy by the current flowing from the coil 1b and performs smoothing. As described above, the voltage conversion unit 1 generates a step-down voltage suitable for a voltage according to regeneration to the battery B1 from a voltage according to electric energy output from the rotating electrical machine.

  Here, in the PWM control when the voltage conversion unit 1 functions as a step-down inverter, the IGBT 1c is DUTY-controlled. This DUTY control is performed according to a step-down ratio that is a ratio between the input voltage and the output voltage. In the case of this embodiment, the input voltage corresponds to a voltage corresponding to the electrical energy charged in the second capacitor 1h by the rotation of the rotating electrical machine. The output voltage corresponds to a voltage suitable for charging the battery B1. The step-down ratio is a ratio obtained by dividing the output voltage by the input voltage. For example, when the difference between the input voltage and the output voltage is small, the step-down ratio is close to 1. In such a case, the on-duty of the IGBT 1c increases. On the other hand, when the difference between the input voltage and the output voltage is large, the step-down ratio is greater than 1. In such a case, the on-duty of the IGBT 1c is reduced. Therefore, when the step-down ratio is reduced, the collector current of the IGBT 1c is increased.

  The frequency conversion unit 2 converts the drive voltage into an AC voltage with the rotating electrical machine as a control target. In the present embodiment, the rotating electrical machine includes a first rotating electrical machine MG1 and a second rotating electrical machine MG2. Therefore, the frequency conversion unit 2 includes the first frequency conversion unit 21 that controls the first rotating electrical machine MG1 and the second frequency conversion unit 22 that controls the second rotating electrical machine MG2. Here, the switching elements included in the first frequency conversion unit 21 and the second frequency conversion unit 22 will also be described as an example of using an IGBT unless otherwise specified, as in the case of the voltage conversion unit 1 described above. . The first frequency conversion unit 21 and the second frequency conversion unit 22 are similar in configuration, and therefore only the first frequency conversion unit 21 will be described below.

  The first frequency converter 21 includes high-side IGBTs 21a, 21b, and 21c that have collector terminals connected to the power supply line 20, and low-side IGBTs 21d, 21e, and 21f that have emitter terminals connected to the negative electrode side of the battery B1. And a total of six IGBTs 21a to 21f. For example, when only the IGBT 21a and the IGBT 21f are simultaneously turned on, each of the IGBTs configured as described above has a current corresponding to the voltage boosted by the voltage conversion unit 1 via the power supply line 20, and the IGBT 21a, the stator coil s1w, the stator. It flows through the coil s1v and the IGBT 21q. On the other hand, when only the IGBT 21b and the IGBT 21d are simultaneously turned on, a current corresponding to the voltage boosted by the voltage conversion unit 1 flows through the power supply line 20 through the IGBT 21b, the stator coil s1u, the stator coil s1w, and the IGBT 21d.

  Thus, the direction of the current flowing through the stator coil s1w differs between the case where only the IGBT 21a and the IGBT 21f are turned on and the case where only the IGBT 21b and the IGBT 21d are turned on. Therefore, an electromagnetic force corresponding to the direction in which the current flows acts on each stator coil, and an attractive force and a repulsive force are generated between the electromagnetic force and a permanent magnet provided in the rotor. Therefore, the rotor can obtain rotational force by sequentially turning on the upper and lower IGBTs formed by the high-side IGBT and the low-side IGBT selected from the IGBTs 21a to 21f. That is, the rotary electric machine MG1 can be driven to rotate. Thus, a collector current flows through each IGBT when a current flows through the stator coil. Here, as described above, in order to increase the output of the rotating electrical machine MG1, it is necessary to increase the current flowing through the stator coil. Therefore, the collector current of the IGBT also increases according to the increase in output required for the rotating electrical machine MG1. The output of the rotating electrical machine is determined according to the torque and the rotational speed of the rotating electrical machine, and corresponds to, for example, the power and power of the rotating electrical machine.

  The ON / OFF control of the IGBTs 21a to 21f is performed by PWM control. The collector currents of the IGBTs 21a to 21f increase when the on-duty increases according to the PWM control, and decrease when the on-duty decreases. The collector currents of the IGBTs 21 a to 21 f also change depending on the boosted voltage generated by the voltage conversion unit 1. That is, as the boosted voltage increases, the potential difference from the power supply line 20 to the negative electrode of the battery B1 increases, so that the collector currents of the IGBTs 21a to 21f also increase. On the other hand, when the boosted voltage is lowered, the potential difference from the power supply line 20 to the negative electrode of the battery B1 is reduced, so that the collector currents of the IGBTs 21a to 21f are also reduced. Such PWM control is controlled by the TCU 10 via the driver 3 (described later).

  As described above, the collector currents of the IGBTs 21a to 21f increase in accordance with the boosted voltage (boost ratio) generated by the voltage conversion unit 1 and the output required for the rotating electrical machine MG1. Therefore, collector losses of the IGBTs 21a to 21f are generated according to the boost ratio and the output required for the rotating electrical machine MG1, and the element temperature increases as the collector loss increases.

  The IGBTs 21a to 21f are provided with diodes 21l to 21q so that the cathode terminal is connected to the collector terminal and the anode terminal is connected to the emitter terminal, respectively. Here, energy is stored in each stator coil during energization. When the rotating electricity MG1 functions as a motor, the diodes 21l to 21q prevent the peripheral components from being adversely affected by the counter electromotive force generated due to the energy when the energization of each stator coil is stopped. It is arranged for this purpose.

  The diodes 21l to 21q constitute a bridge rectifier circuit together with the second smoothing capacitor 1h when the rotating electrical machine MG1 functions as a generator. When the rotating electrical machine MG1 functions as a generator, for example, when the energy stored by the current flowing from the stator coil s1w to the stator coil s1u is extracted, s1w, the diode 21l, the second smoothing capacitor 1h, the diode When current flows through 21p and s1u, electrical energy corresponding to the current is stored in the second smoothing capacitor 1h. And according to rotation of the rotary electric machine MG1, electric energy is also stored in the second smoothing capacitor 1h from other stator coils. This electric energy is used as electric power for driving the rotary electric machine MG2. In order to regenerate the electric energy to the battery B1, the voltage conversion unit 1 steps down the voltage based on the electric energy to a voltage suitable for charging the battery B1, so that a charging current flows through the battery B1. Become. Therefore, the battery B1 can be charged.

  Similarly to the first frequency conversion unit 21, the second frequency conversion unit 22 includes a plurality of IGBTs 22a to 22f and a plurality of diodes 22l to 22q. Since the function is the same as that of the first frequency converter 21, description thereof is omitted.

  The element temperature detection unit 5 detects the element temperature of the IGBT. The element temperature is not limited to that which means an IGBT chip, but may be the temperature of a resin mold in which the IGBT chip is enclosed. Here, as described above, the IGBT is provided in each of the voltage generation unit 1, the first frequency conversion unit 21, and the second frequency conversion unit 22. Therefore, the element temperature detection unit 5 is provided as each of the element temperature detection units 51 to 53 in order to detect the element temperature of the IGBT included in each functional unit.

  The element temperature detection unit 51 provided in the voltage conversion unit 1 detects the element temperatures of the IGBTs 1c and 1d. As described above, the collector current flows through the IGBT 1d when the voltage generation unit 1 functions as a step-up converter, and the collector current flows through the IGBT 1c when the voltage generation unit 1 functions as a step-down converter. As described above, the IGBT through which the collector current flows generates heat according to the collector-emitter voltage and the collector current. The element temperature detection unit 51 detects the element temperature of the IGBT that generates heat in this way. In the present embodiment, the element temperature of a plurality of IGBTs is detected by one element temperature detection unit 51. Therefore, it may be provided near the approximate center of the IGBTs 1c and 1d, or may be provided near either one of the IGBTs 1c and 1d, and may be obtained by correcting each element temperature based on the detection result. The detection result detected by the element temperature detection unit 51 is transmitted to the TCU 10 described later as element temperature information.

  The element temperature detection unit 52 provided in the first frequency conversion unit 21 detects the element temperatures of the IGBTs 21a to 21f. As described above, in these IGBTs 21a to 21f, when a current flows through a stator coil included in the rotating electrical machine MG1, a collector current flows through a pair of IGBTs selected from a high-side IGBT and a low-side IGBT. Therefore, the IGBT through which the collector current flows generates a collector loss according to the collector-emitter voltage and the collector current, and generates heat according to the collector loss. The element temperature detection unit 52 detects such an element temperature of the IGBT. In the present embodiment, the element temperature of a plurality of IGBTs is detected by one element temperature detection unit 52. Therefore, the element temperature detection unit 52 may be provided near the approximate center of the IGBTs 21a to 21f, or may be provided near any of the IGBTs, and each element temperature may be corrected and obtained based on the detection result. Also good. The detection result detected by the element temperature detection unit 52 is transmitted to the TCU 10 described later as element temperature information.

  The second frequency conversion unit 22 includes an element temperature detection unit 53. Since the configuration is the same as that of the element temperature detection unit 52 provided in the first frequency conversion unit 21, description thereof is omitted.

  The current detection unit 6 detects the current flowing through the stator coil of the rotating electrical machine. The current detection unit 6 includes a current detection unit 61 that detects a current flowing in the stator coil of the rotating electrical machine MG1, and a current detection unit 62 that detects a current flowing in the stator coil of the rotating electrical machine MG2. Although FIG. 1 shows a configuration in which the currents of all three phases are measured, since the three phases are in an equilibrium state and the sum of instantaneous values is zero, only the currents of the two phases are measured and the phase difference is measured. The remaining one-phase current may be calculated by calculation. The detection result detected by the current detector 6 is transmitted to the TCU 10 described later as current value information.

  The rotation angle detector 7 detects the rotation angle of the rotor of the rotating electrical machine. The rotation angle detection unit 7 includes a first rotation angle detection unit 71 that detects the rotation angle of the rotor of the rotary electric machine MG1, and a second rotation angle detection unit 72 that detects the rotation angle of the rotor of the rotary electric machine MG2. Composed. The rotation angle detection unit 7 converts the rotation angle of the rotor into an electrical angle θ and outputs a signal corresponding to the electrical angle θ to the TCU 10 as rotation angle information.

  The TCU 10 functions as a control unit, controls the voltage conversion unit 1 and the frequency conversion unit 2, and controls the first rotating electrical machine MG1 and the second rotating electrical machine MG2. In the above description, the voltage conversion unit 1 and the frequency conversion unit 2 have been described as being controlled by PWM control, but this PWM control is performed by the TCU 10. Further, the TCU 10 has a function of rotating the first rotating electrical machine MG1 and the second rotating electrical machine MG2 with high output and high efficiency so as to realize the object of the present invention. Below, the control which TCU10 performs is demonstrated.

  FIG. 2 is a diagram illustrating a functional configuration of the TCU 10. The TCU 10 includes a battery current estimation unit 10a, a first surge voltage estimation unit 10c, a first surge voltage map storage unit 10d, a first limit value determination unit 10e, a first element withstand voltage map storage unit 10f, and a first torque control value calculation unit. 10g, first current command value calculation unit 10h, first PWM control unit 10i, second surge voltage estimation unit 10j, second surge voltage map storage unit 10k, second limit value determination unit 101, second element withstand voltage map storage unit 10m A second torque control value calculation unit 10n, a second current command value calculation unit 10o, a second PWM control unit 10p, a third surge voltage estimation unit 10q, a third surge voltage map storage unit 10r, a third limit value determination unit 10s, Each functional unit includes a third element withstand voltage map storage unit 10t, a common limit value determination unit 10u, a voltage conversion PWM control unit 10v, and a switching speed determination unit 10w. In the TCU 10, the above-described functional units for performing various processes for controlling the control device 100 are constructed by hardware and / or software, with a CPU as a core member.

  The first torque control value calculation unit 10g calculates a target torque required for the rotating electrical machine MG1 in order to cause the hybrid vehicle to travel appropriately. The calculation of the target torque is performed according to the traveling state of the vehicle, the operation of the driver, and the like. A signal indicating the calculated target torque is transmitted as the first torque command value to the battery current estimation unit 10a and the first current command value calculation unit 10h.

  The first current command value calculation unit 10h calculates, as the first current command value, the current that flows through the stator coil of the rotating electrical machine MG1 based on the first torque command value and the rotational speed of the rotating electrical machine MG1. The rotational speed of the rotating electrical machine MG1 is calculated based on the rotational angle information transmitted from the first rotational angle detection unit 71 described above. The first current command value is transmitted to the first PWM control unit 10i, the second surge voltage estimation unit 10j, and the voltage conversion PWM control unit 10v.

  The 1st PWM control part 10i produces | generates the PWM control signal which performs PWM control of IGBT21a-21f with which the 1st frequency conversion part 21 is provided based on the above-mentioned 1st electric current command value. The PWM control signal generated by the first PWM control unit 10i is transmitted to a driver 32 (see FIG. 1) described later.

  The second surge voltage map storage unit 10k stores a second surge voltage map indicating a relationship between a surge voltage and a collector current generated in the IGBTs 21a to 21f included in the first frequency conversion unit 21. The surge voltage is a pulse voltage generated particularly when the IGBT is switched from ON to OFF. This surge voltage changes according to the collector current of the IGBT. An example of the second surge voltage map showing such a relationship is shown in FIG. As shown in FIG. 3, in the second surge voltage map, the horizontal axis represents the collector current and the vertical axis represents the surge voltage. As indicated by the solid line in FIG. 3, the surge voltage increases as the collector current increases. In the present embodiment, the voltage value of the surge voltage is used for the purpose of protecting the IGBT element breakdown voltage, as will be described in detail later. Therefore, the second surge voltage map defines the maximum value of the surge voltage that can be generated according to the collector current.

  The second surge voltage estimation unit 10j estimates the surge voltage generated in the IGBTs 21a to 21f included in the first frequency conversion unit 21 as the second surge voltage based on the first current command value. As described above, since the surge voltage changes according to the collector current of the IGBT, it is possible to estimate the surge voltage using the current indicated by the first current command value as the collector current. The second surge voltage estimation unit 10j estimates the second surge voltage based on the second surge voltage map stored in the second surge voltage map storage unit 10k. When the first current command value calculation unit 10h transmits that the first current command value is I0 [A], the second surge voltage estimation unit 10j receives the second surge voltage as shown in FIG. Using the map, it is estimated that the surge voltage generated in the IGBTs 21a to 21f is V01 [V]. The estimated value of the surge voltage estimated by the second surge voltage estimating unit 10j is transmitted to the second limit value determining unit 101 described later.

  The second element breakdown voltage map storage unit 10m stores a second element breakdown voltage map indicating the relationship between the element temperature and the element breakdown voltage of the IGBTs 21a to 21f included in the first frequency conversion unit 21. The element breakdown voltage refers to the breakdown voltage between the collector and the emitter of the IGBT, and is generally equivalent to that indicated by the absolute maximum rating. This element withstand voltage changes according to the element temperature of the IGBT. An example of the second element breakdown voltage map showing such a relationship is shown in FIG. As shown in FIG. 4, in the second element breakdown voltage map, the horizontal axis indicates the IGBT element temperature, and the vertical axis indicates the element breakdown voltage. As shown in FIG. 4, the device breakdown voltage decreases as the device temperature decreases.

  The second limit value determination unit 101 determines the drive voltage limit value in the first frequency conversion unit 21 as the second limit value based on the element temperatures of the IGBTs 21a to 21f included in the first frequency conversion unit 21. As described above, the element temperatures of the IGBTs 21a to 21f are detected by the element temperature detection unit 52 and transmitted to the second limit value determination unit 10l as element temperature information. The drive voltage is a voltage necessary for driving the rotary electric machine MG1, and corresponds to a boosted voltage generated by the voltage conversion unit 1. Here, as described above, a surge voltage is generated in the IGBT according to the collector current. The limit value is a limit value of the drive voltage that is set so that the sum of the drive voltage and the surge voltage does not exceed the element breakdown voltage of the IGBT. The second limit value is determined by subtracting the estimated value of the surge voltage generated according to the current (collector current) flowing through the IGBTs 21a to 21f from the element breakdown voltage determined according to the element temperature of the IGBTs 21a to 21f. The estimated value of the surge voltage is transmitted from the second surge voltage estimation unit 10j as described above.

  This will be specifically described with reference to FIG. When element temperature information indicating that the element temperatures of the IGBTs 21a to 21f are T0 [° C.] is transmitted, the second limit value determining unit 10l receives the second element breakdown voltage stored in the second element breakdown voltage map storage 10m. Based on the map, the element breakdown voltage at T0 [° C.] is specified to be V0 [V]. If the estimated value of the surge voltage transmitted from the second surge voltage estimation unit 10j is V01 [V], V1 [V] obtained by subtracting V01 [V] from V0 [V] is used as the second limit value. decide. The second limit value determined in this way is transmitted to the common limit value determination unit 10u as the drive voltage limit value in the first frequency converter 21.

  Further, the second torque control value calculation unit 10n, the second current command value calculation unit 10o, the second PWM control unit 10p, the third surge voltage estimation unit 10q, the third surge voltage map storage unit 10r, and the third limit value determination unit 10s. The third element breakdown voltage map storage unit 10t includes the first torque control value calculation unit 10g, the first current command value calculation unit 10h, the first PWM control unit 10i, the second surge voltage estimation unit 10j, and the second surge voltage map. The same processing as that of the storage unit 10k, the second limit value determination unit 101, and the second element breakdown voltage map storage unit 10m is performed. Therefore, only the differences are described below.

  Second torque control value calculation unit 10n calculates a target torque required for rotating electrical machine MG2. A signal indicating the calculated target torque is transmitted to the battery current estimation unit 10a and the second current command value calculation unit 10o as a second torque command value. The second current command value calculated by the second current command value calculation unit 10o is transmitted to the second PWM control unit 10p, the third surge voltage estimation unit 10q, and the voltage conversion PWM control unit 10v. Further, the PWM control signal generated by the second PWM control unit 10p is transmitted to the driver 33 described later.

  Further, the third limit value determination unit 10s determines the drive voltage of the second frequency conversion unit 22 based on the element temperatures of the IGBTs 22a to 22f included in the second frequency conversion unit 22 that controls the rotating electrical machine MG2. The limit value is determined as the third limit value. The third limit value determined by the third limit value determining unit 10s is transmitted to the common limit value determining unit 10u.

  The battery current estimation unit 10a estimates the battery current based on the total power required to drive the rotating electrical machine and the battery voltage output from the battery B1. The total power used here is the power obtained by multiplying the first torque command value of the rotating electrical machine MG1 and the rotational speed and the power obtained by multiplying the second torque command value of the rotating electrical machine MG2 and the rotational speed. Is the sum of As described above, the first torque command value is transmitted from the first torque control value calculation unit 10g, and the second torque command value is transmitted from the second torque control value calculation unit 10n. The battery current estimation unit 10a estimates the battery current by dividing the total power necessary for driving both the rotating electrical machine MG1 and the rotating electrical machine MG2 by the battery voltage. The battery current estimated by the battery current estimation unit 10a is transmitted to the first surge voltage estimation unit 10c.

  The first surge voltage map storage unit 10d stores a first surge voltage map indicating the relationship between the surge voltage and collector current of the IGBTs 1c and 1d included in the voltage conversion unit 1. As described above, the surge voltage is a pulse voltage generated particularly when the IGBT is turned from ON to OFF. This surge voltage changes according to the collector current of the IGBT. In the following description, it is assumed that the first surge voltage map is the same as that shown in FIG.

  The first surge voltage estimation unit 10c estimates the surge voltage generated in the IGBTs 1c and 1d as the first surge voltage based on the battery current described above. As described above, since the surge voltage changes according to the collector current of the IGBT, the surge voltage can be estimated from the collector current. Therefore, the first surge voltage estimation unit 10c estimates the first surge voltage based on the first surge voltage map stored in the first surge voltage map storage unit 10d. When the battery current estimation unit 10a transmits that the battery current is I0 [A], the first surge voltage estimation unit 10c uses the first surge voltage map as shown in FIG. It is estimated that the voltage is V01 [V]. The estimated value of the surge voltage estimated by the first surge voltage estimating unit 10c is transmitted to the first limit value determining unit 10e described later.

  The first element breakdown voltage map storage unit 10f stores a first element breakdown voltage map indicating the relationship between the element temperature of the IGBTs 1c and 1d and the element breakdown voltage. The element breakdown voltage refers to the breakdown voltage between the collector and the emitter of the IGBT, and is generally equivalent to that indicated by the absolute maximum rating. This element withstand voltage changes according to the element temperature of the IGBT. In the following description, it is assumed that the first element breakdown voltage map is the same as that shown in FIG.

  The first limit value determination unit 10e determines the limit value of the drive voltage in the voltage conversion unit 1 as the first limit value based on the element temperatures of the IGBTs 1c and 1d included in the voltage conversion unit 1. As described above, the element temperatures of the IGBTs 1c and 1d are detected by the element temperature detection unit 51 and transmitted as element temperature information to the first limit value determination unit 10e. The drive voltage is a voltage necessary for driving the rotary electric machines MG1 and MG2, and corresponds to a boosted voltage generated by the voltage conversion unit 1. Here, as described above, a surge voltage is generated in the IGBT according to the collector current. The limit value is a limit value that is set so that the collector-emitter voltage and the surge voltage do not exceed the device breakdown voltage of the IGBT. The first limit value is determined by subtracting the estimated value of the surge voltage generated according to the current flowing through the IGBT 1c, 1d from the element breakdown voltage determined according to the element temperature of the IGBT 1c, 1d. The estimated value of the surge voltage is transmitted from the first surge voltage estimation unit 10c as described above.

  This will be specifically described with reference to FIG. When element temperature information indicating that the element temperatures of the IGBTs 1c and 1d are T0 [° C.] is transmitted, the first limit value determination unit 10e stores the first element breakdown voltage stored in the first element breakdown voltage map storage 10f. Based on the map, the element withstand voltage V0 [V] at T0 [° C.] is specified. If the estimated value of the surge voltage transmitted from the first surge voltage estimating unit 10c is V01 [V], V1 [V] obtained by subtracting V01 [V] from V0 [V] is used as the first limit value. decide. The first limit value determined in this way is transmitted to the common limit value determination unit 10u as the drive voltage limit value in the voltage converter 1.

  The common limit value determining unit 10u determines the lowest limit value among the first limit value, the second limit value, and the third limit value as the common limit value. As described above, the first limit value is transmitted from the first limit value determination unit 10e as the drive voltage limit value in the voltage conversion unit 1. Further, the second limit value is transmitted from the second limit value determining unit 101 as a drive voltage limit value in the first frequency converting unit 21. Further, the third limit value is transmitted from the third limit value determining unit 10 s as the drive voltage limit value in the second frequency converting unit 22. The common limit value determining unit 10u determines the lowest limit value from among these as the common limit value. The determined common limit value is transmitted to a voltage conversion PWM control unit 10v and a switching speed determination unit 10w, which will be described later.

  The voltage conversion PWM control unit 10v performs PWM control of the IGBTs 1c and 1d included in the voltage conversion unit 1. The voltage conversion PWM control unit 10v receives the first current command value from the first current command value calculation unit 10h and the second current command value from the second current command value calculation unit 10o. The common limit value is also transmitted from the common limit value determination unit 10u. Further, an output voltage (corresponding to a driving voltage of the rotating electrical machine) is also transmitted from the power supply line 20 that is an output of the voltage conversion unit 1.

  Here, the voltage conversion PWM control unit 10v includes an error amplifier and a PWM comparator (both not shown). The error amplifier has a voltage based on an output voltage from the power supply line 20 (for example, a voltage obtained by resistance voltage division) and an output voltage determined based on the first current command value and the second current command value. Comparison with the reference voltage according to the target value is performed. In this comparison, it is preferable that a voltage based on the output voltage is input to the inverting terminal of the error amplifier and the above-described reference voltage is input to the non-inverting terminal of the error amplifier. The comparison result (output of the error amplifier) thus compared is input to the PWM comparator.

  In the PWM comparator, logic is set so as to limit the output voltage to a common limit value or less. For example, the output of the error amplifier described above is input to the first non-inverting terminal of the PWM comparator, and the voltage based on the common limit value (for example, the voltage obtained by resistance voltage division) is input to the second non-inverting terminal. To do. Then, a waveform (for example, a triangular wave or a sine wave having a predetermined frequency) that is the basis of PWM control is input to the inverting terminal of the PWM comparator. With such a configuration, the output voltage of the voltage conversion unit 1 can be limited to a common limit value or less. The output of the PWM comparator becomes a PWM control signal for performing ON / OFF control of the IGBTs 1c and 1d included in the voltage converter 1, and is transmitted to a driver 31 described later. The voltage conversion unit 1 generates the boosted voltage based on such a PWM control signal and while controlling the boosted voltage to be equal to or less than the common limit value as described above.

  As described above, the element breakdown voltage determined according to the element temperature of the IGBTs 1c and 1d included in the voltage conversion unit 1, the IGBTs 21a to 21f included in the first frequency conversion unit 21, and the IGBTs 22a to 22f included in the second frequency conversion unit 22. By determining the limit value of the drive voltage generated by the voltage conversion unit 1 based on the above, the device breakdown voltage of the IGBTs 1c, 1d, IGBTs 21a-21f, and IGBTs 22a-22f changes according to the respective device temperatures. However, the voltage applied to each switching element can be controlled so as not to exceed the element breakdown voltage. For this reason, since the drive voltage according to the element temperature of IGBT1c, 1d, IGBT21a-21f and IGBT22a-22f which changes according to the driving | running state of a control apparatus is supplied to each IGBT, the voltage added to each IGBT exceeds element withstand voltage | pressure. A high voltage can be supplied to the IGBT in a range that does not exist. Therefore, high output of the rotating electrical machine can be achieved. Furthermore, since it is not necessary to set the device withstand voltage based on the situation where the temperature condition is bad, that is, the device temperature is very low, it is not necessary to use an IGBT with excellent withstand voltage characteristics, and it is possible to reduce the cost. It becomes.

  The switching speed determination unit 10w changes the switching speed of the IGBT. The IGBT to be changed is an IGBT included in each functional unit (the voltage conversion unit 1, the first frequency conversion unit 21, and the second frequency conversion unit 22).

  For example, when the common limit value determining unit 10u determines that the limit value related to the second limit value is the common limit value, the first limit value and the third limit value are less than the common limit value. Therefore, the switching speed of the IGBT included in the function unit (the voltage conversion unit 1 and the second frequency conversion unit 22) determined using the first limit value and the third limit value as the limit value of the drive voltage is increased. Further, the switching speed of the IGBT included in the functional unit (first frequency conversion unit 21) having the limit value determined as the common limit value is also increased. By increasing the switching speed in this way, switching loss can be reduced. Therefore, the efficiency according to the control device 100 can be increased.

  In this way, the switching speed can be changed according to the difference between the limit value related to the functional unit and the drive voltage. In other words, if the target of increasing the switching speed is the IGBTs 1c and 1d included in the voltage conversion unit 1, the switching speed is increased according to the difference between the first limit value and the drive voltage. Moreover, if the object which accelerates | stimulates switching speed is IGBT21a-21f with which the 1st frequency conversion part 21 is provided, it will be accelerated according to the difference of a 2nd limit value and a drive voltage. Furthermore, if the target of increasing the switching speed is the IGBTs 22a to 22f included in the second frequency conversion unit 22, the switching speed is increased according to the difference between the third limit value and the drive voltage. The switching speed determination unit 10w transmits the switching speed information to the driver power supply unit 4 (described later) in order to change the switching speed of the IGBT to be changed. Here, when there is no difference between the limit value of each function unit and the drive voltage, the switching speed of the IGBT of the function unit having the limit value is not changed. In this case, switching speed information indicating that the switching speed is not changed is transmitted to the driver power supply unit 4 having the IGBT that is not to be changed.

  Returning to FIG. 1, the driver power supply 4 supplies power to the driver 3 that drives the IGBT. The driver power supply 4 supplies power to the driver power supply 41 that supplies power to the driver 3 that drives the IGBTs 1 c and 1 d of the voltage converter 1 and the driver 3 that drives the IGBTs 21 a to 21 f of the first frequency converter 21. And a driver power supply unit 43 that supplies power to the driver 3 that drives the IGBTs 22 a to 22 f of the second frequency conversion unit 22. Switching speed information is input to each of the driver power supply units 41 to 43 from the switching speed determining unit 10w. The driver power supply units 41 to 43 generate a power supply voltage corresponding to the switching speed of the switching speed information and supply power to the driver 3.

  FIG. 5 shows a circuit configuration of the driver power supply unit 4. Each of the driver power supply units 41 to 43 includes the same one. The driver power supply unit 4 includes a PWM control unit 4a, a coil 4b, a bipolar transistor 4c, a diode 4d, and a smoothing capacitor 4e. A low-voltage battery B2 and a collector terminal of the bipolar transistor 4c are connected to both ends of the primary side of the coil 4b. The emitter terminal of the bipolar transistor 4c is grounded, and the PWM control signal output from the PWM controller 4a is input to the base terminal. The PWM control unit 4a receives the output voltage V4 output from the cathode terminal of the diode 4d together with the switching speed information transmitted from the switching speed determination unit 10w.

  The PWM control unit 4a performs PWM control on the bipolar transistor 4c according to the switching speed information and the output voltage V4. That is, when the switching speed information includes information indicating that the switching speed is not changed, the PWM control unit sets the output voltage V4 of the driver power supply 4 to a preset voltage (for example, 15V). The bipolar transistor 4c is PWM controlled so that Further, when the switching speed information includes information indicating that the switching speed is changed, the PWM control unit sets the output voltage V4 of the driver power supply unit 4 to the switching speed included in the switching speed information. The bipolar transistor 4c is subjected to PWM control so that the corresponding voltage V4 (for example, 17V) is obtained. The output voltage V4 can be changed according to the ON DUTY of the bipolar transistor 4c. The output voltage V4 increases as the ON DUTY increases, and the output voltage V4 decreases as the ON DUTY decreases. .

  One end of the secondary side of the coil 4b is grounded, and the other end is connected to the anode of the diode 4d. The cathode of the diode 4d becomes the output voltage of the driver power supply unit 4, and a smoothing capacitor 4e is provided. The diode 4d is provided for rectifying the counter electromotive force of the coil 4b generated according to the PWM control of the bipolar transistor 4c, and the smoothing capacitor 4e is provided for smoothing the output voltage V4. The output voltage V4 is supplied to the driver 3 described later. Note that the output voltage V4 of each of the driver power supply units 41 to 43 can be set to a different voltage according to the switching speed information from the switching speed determining unit 10w. That is, the output voltage V4 of each driver power supply unit 41 to 43 is output according to the switching speed of the IGBT provided in the voltage conversion unit 1, the first frequency conversion unit 21, and the second frequency conversion unit 22.

  The driver 3 drives the IGBT. The driver 3 includes a driver 31 that drives the IGBTs 1c and 1d of the voltage converter 1, a driver 32 that drives the IGBTs 21a to 21f of the first frequency converter 21, and IGBTs 22a to 22f of the second frequency converter 22. It comprises a driver 33 for driving. The output voltage of each driver power supply unit 4 is input to each driver 3. That is, the output voltage of the driver power supply unit 41 is input to the driver 31, and the output voltage of the driver power supply unit 42 is input to the driver 32. The output voltage of the driver power supply unit 43 is input to the driver 33.

  Here, the TCU 10 is configured by, for example, a microcomputer that operates at a low voltage such as 2.5 V or 3.3 V. Therefore, depending on the current flowing through the IGBT and the electrical characteristics of the IGBT, the PWM control signal output from each of the first PWM control unit 10i, the second PWM control unit 10p, and the voltage conversion PWM control unit 10v may change each IGBT. There is a risk that the drive capacity for turning on will be insufficient and the collector current required will not flow. Therefore, the driver 3 is provided to increase the drive capability of the PWM control signal output from each of the first PWM control unit 10i, the second PWM control unit 10p, and the voltage conversion PWM control unit 10v.

  FIG. 6 shows a circuit configuration of the driver 3. FIG. 6 shows the driver 31, but basically the other drivers 32 and 33 are the same. Further, the description will be made assuming that the IGBT driven by the driver 31 is the IGBT 1d. The driver 31 includes a pair of bipolar transistors 3a and 3b that form a push-pull, and control resistors 3c and 3d. The push-pull high-side bipolar transistor 3a is an NPN transistor, and the low-side bipolar transistor 3b is a PNP-type transistor. The bipolar transistors 3a and 3b are connected as a base common and an emitter common. The output voltage V4 of the driver power supply 41 is supplied to the collector terminal of the bipolar transistor 3a. On the other hand, the collector terminal of the bipolar transistor 3b is grounded. Control resistors 3c and 3d are connected to an emitter terminal which is an emitter common. These midpoints 3e are connected to a gate terminal which is a control terminal of the IGBT 1d.

  If the PWM control signal transmitted from the voltage conversion PWM controller 10v is Hi, the bipolar transistor 3a is turned on (the bipolar transistor 3b is turned off), and the output voltage V4 is applied to the control resistors 3c and 3d. On the other hand, if the PWM control signal is Low, the bipolar transistor 3b is turned on (the bipolar transistor 3a is turned off), and the output voltage V4 is not applied to the control resistors 3c and 3d. The resistance values of the control resistors 3c and 3d are determined so that the voltage at the middle point 3e when the bipolar transistor 3a is turned on is equal to or higher than the threshold value for driving the IGBT 1d.

  With this configuration, the driver 31 can use the output voltage V4 of the driver power supply unit 41 to increase the driver ability to drive the IGBT 1d. As described above, when the switching speed determination unit 10w of the TCU 10 changes the switching speed, the driver power supply unit 41 increases the output voltage V4 from a preset voltage value. For this reason, the potential of the middle point 3e of the control resistors 3c and 3d is also increased. Therefore, since the drive voltage for driving the IGBT 1d is increased, the switching speed of the IGBT 1d is increased. The control device 100 thus changes the switching speed of the IGBT 1d by changing the output voltage V4 applied to the control resistors 3c and 3d connected to the gate terminal of the IGBT 1d. The configuration related to the driver power supply 41 and the driver 31 is the same for the other driver power supplies 42 and 43 and the drivers 32 and 33. Therefore, the description is omitted.

  As described above, the control device 100 can reduce the switching loss in each IGBT by increasing the switching speed of the IGBT of the functional unit having a margin with respect to the common limit value. Therefore, the efficiency according to the control device 100 can be increased.

Here, the processing related to the present control apparatus 100 is organized using the drawings.
When switching an n-channel IGBT, a PWM control signal as shown in FIG. 7A is applied to the gate terminal of the IGBT. However, in FIG. 7A, only a predetermined period of the PWM control signal is shown. When a PWM control signal as shown in (a) is applied to the gate terminal of the IGBT, the collector-emitter voltage is turned on in accordance with the PWM control signal shown in (a) as shown in (b). And turned off. In this case, a surge voltage is generated particularly during turn-off. On the other hand, a collector current flows as shown in FIG. If such a surge voltage exceeds the device breakdown voltage of the IGBT, the IGBT may be destroyed. For this reason, the TCU 10 determines the drive voltage limit values in the voltage conversion unit 1, the first frequency conversion unit 21, and the second frequency conversion unit 22 in consideration of such a surge voltage.

  This determination is made using the surge voltage map shown in FIG. 3 based on the collector current of the IGBT. If the collector current is I0 [A], the surge voltage generated in the IGBT is estimated to be V01 [V].

  On the other hand, the element temperature of the IGBT is measured by the element temperature detection unit 5. If the IGBT element temperature is T0 [° C.], the IGBT element withstand voltage at that temperature is V0 [V] as shown in the element withstand voltage map shown in FIG. Here, the TCU 10 determines the limit value at the temperature as V1 [V] by subtracting the estimated surge voltage V01 [V] from the element breakdown voltage. Such processing is performed on each functional unit of the voltage conversion unit 5, the first frequency conversion unit 21, and the second frequency conversion unit 22. The limit value of each functional unit is determined as a first limit value, a second limit value, and a third limit value, respectively.

  Then, the TCU 10 determines the lowest limit value among these limit values as the common limit value. Here, it is assumed that the second limit value is set as the common limit value. The voltage conversion unit 1 generates a boosted voltage from the output of the battery B1 by limiting the drive voltage generated by the voltage conversion unit 1 to a common limit value or less. The control device 100 uses the boosted voltage as a driving voltage for the rotating electrical machine and controls the voltage conversion unit 1, the first frequency conversion unit 21, and the second frequency conversion unit 22.

  Here, as described above, the collector-emitter voltage of the IGBT in this state has a waveform as shown in FIG. On the other hand, the collector current has a waveform as shown in FIG. Therefore, the switching loss can be estimated as the product of the collector-emitter voltage and the collector current, and corresponds to the area of the hatched region where (b) and (c) intersect. The calculation result is shown by (d) in FIG. In (d), the loss related to the collector-emitter saturation voltage when the IGBT is on is ignored.

  In order to reduce such switching loss, it is preferable to increase the switching speed. Therefore, the TCU 10 performs control so as to increase the switching speed of the functional unit having a limit value that is not the lowest limit value among the first limit value, the second limit value, and the third limit value. That is, control is performed so as to increase the switching speed of the IGBT provided in the voltage conversion unit 1 and the second frequency conversion unit 21.

  Here, the switching speed is increased according to the difference between the limit value and the drive voltage in each functional unit. For example, when the difference between the first limit value and the drive voltage in the voltage converter 1 is V02 [V], the surge voltage is calculated when the collector current is I0 [A] using the surge voltage map of FIG. Specifies a power supply voltage that becomes V02 [V] or less. In this case, the switching speed determination unit 10w specifies the power supply voltage supplied to the driver 31 as 17V, as indicated by the one-dot chain line in FIG. This 17 [V] is merely an example and is not limited. This power supply voltage is determined according to the characteristics of the IGBT.

  Then, the TCU 10 instructs the driver power supply unit 41 to change the driver power supply so that the IGBT included in the voltage conversion unit 1 is driven with the specified power supply voltage. When the power supply voltage supplied to the driver 31 is changed in this way, the PWM control signal applied to the IGBT 1c is more than that shown in FIG. 7A as shown in FIG. Speeded up. When the PWM control signal shown in FIG. 8A is applied, as shown in FIG. 8B, the collector-emitter voltage is turned on and off according to the PWM control signal shown in FIG. Turned off. In this case, a surge voltage is generated particularly during turn-off.

  This surge voltage is larger than that shown in FIG. On the other hand, a collector current flows as shown in FIG. However, even if the surge voltage increases, the IGBT 1c has no problem because it has a margin with respect to the surge voltage. As in FIG. 7, the switching loss corresponds to the area of the hatched region where (b) and (c) of FIG. 8 intersect. The calculation result is shown in FIG. As apparent from the fact that the area of FIG. 8D is smaller than the area of FIG. 7D, the switching loss is reduced as the switching speed is increased. Therefore, the efficiency can be increased when the entire control apparatus 100 is considered.

  In this way, since the present control device 100 supplies each IGBT with the drive voltage determined based on the IGBT element temperature that changes in accordance with the operation status of the control device 100, it does not exceed the device breakdown voltage of each IGBT. It is possible to perform switching at a high voltage in the range. Therefore, high output of the rotating electrical machine can be achieved. In addition, since the device withstand voltage is set according to the device temperature, it is not necessary to use an IGBT having excellent withstand voltage characteristics, so that the cost can be reduced. Furthermore, the switching speed can be increased according to the margin of the IGBT having a margin of device breakdown voltage. Therefore, the switching loss of each IGBT can be reduced and the efficiency can be further increased.

[Other Embodiments]
In the above embodiment, the case where the present control device 100 is applied to a hybrid vehicle has been described as an example. However, the scope of application of the present invention is not limited to this. For example, it is naturally possible to apply the control device 100 to an electric vehicle using only a rotating electrical machine as a power source. Even when the present invention is applied to an electric vehicle, the above-described effects can be obtained. Moreover, in the said embodiment, it demonstrated as an example in case a hybrid vehicle is provided with two rotary electric machines. However, the scope of application of the present invention is not limited to this. Even if the hybrid vehicle has one rotating electric machine, it is naturally possible to apply the control device 100 according to the present invention, and the above-described effects can be obtained.

  In the above embodiment, the switching speed of the IGBT has been described as being changed by changing the power supply voltage supplied from the driver power supply unit 4 to the driver 3. However, the scope of application of the present invention is not limited to this. For example, the resistance values of the control resistors 3c and 3d included in the driver 3 can be changed. Specifically, at least one of the control resistors 3c and 3d can be configured to include a resistor in parallel connection, and can be realized by connecting or disconnecting the resistor according to switching speed information. It is. Furthermore, when it is desired to control the resistance value flexibly, the resistor can be changed by using an electronically controlled potentiometer.

  In the said embodiment, the switching element with which the voltage converter 1 and the frequency converter 2 are provided was demonstrated as IGBT. However, the scope of application of the present invention is not limited to this. For example, it is possible to use a MOS-FET instead of the IGBT, and naturally use a bipolar transistor. Even when such an element is used, it is naturally possible to realize the rotating electrical machine control device 100 according to the present invention. When a MOS-FET is used as the switching element, in the above-described embodiment, “collector current” corresponds to “drain current”, and “collector-emitter voltage” becomes “drain-source voltage”. Equivalent to.

  In the above embodiment, the case where a plurality of rotating electrical machines are provided has been described as an example. However, the scope of application of the present invention is not limited to this. Even if there is only one rotating electrical machine, it is possible to configure the rotating electrical machine control apparatus 100 according to the present invention. In this case, the frequency conversion unit 2 also includes one, and the common limit value determination unit 10u determines the lower limit value of the first limit value in the voltage conversion unit 1 and the second limit value in the frequency conversion unit 2. It is preferable to determine the common limit value. Even with such a configuration, it is naturally possible to obtain the effects according to the present invention.

  In the said embodiment, the element temperature detection part 5 was demonstrated as one provided in the function part of the voltage conversion part 1, the 1st frequency conversion part 21, and the 2nd frequency conversion part 22, respectively. However, the scope of application of the present invention is not limited to this. For example, it is possible to provide the element temperature detection unit 5 in a one-to-one correspondence with each IGBT. Or it is also possible to comprise one each in the high side and low side of IGBT of each function part. In the case of such a configuration, it is preferable that the TCU 10 uses the highest temperature detection result from each element temperature detection unit 5 as element temperature information.

  In the above embodiment, the element temperature of the IGBT is described as being detected by the element temperature detection unit 5. However, the scope of application of the present invention is not limited to this. The element temperature can also be calculated. When the switching element is an IGBT or a bipolar transistor, the chip temperature can be calculated from the collector-emitter voltage, the collector current, and the thermal resistance of the mold enclosing the chip. When the switching element is a MOS-FET, the chip temperature can be calculated from the on-resistance, the drain current, and the thermal resistance of the mold enclosing the chip. It is naturally possible to calculate the chip temperature in this way and control the control device 100 according to the present invention based on the chip temperature.

  In the above embodiment, the first surge voltage map stored in the first surge voltage map storage unit 10d, the second surge voltage map stored in the second surge voltage map storage unit 10k, and the third surge voltage map storage unit. The third surge voltage map stored in 10r has been described as being provided separately. However, the scope of application of the present invention is not limited to this. For example, when the same IGBT is used in the voltage conversion unit 1, the first frequency conversion unit 21, and the second frequency conversion unit 22, the first surge voltage map storage unit 10d and the second surge voltage map are used. The storage unit 10k and the third surge voltage map storage unit 10r may be configured as a single surge voltage map storage unit in common and provided with a surge voltage map storage unit.

  In the said embodiment, the surge voltage estimated based on the surge voltage map demonstrated as a maximum value. However, the scope of application of the present invention is not limited to this. For example, the surge voltage map shows an average value of the surge voltage, and each surge voltage estimation unit 10c, 10j, 10q considers derating from the average value and estimates the maximum value of the surge voltage. It is also possible to do.

  In the embodiment described above, the relationship between the surge voltage and the collector current in each functional unit has been described on the assumption that the collector current is I0 [A] and the surge voltage at that time is V01 [V]. However, the scope of application of the present invention is not limited to this. I0 [A] and V01 [V] are merely examples, and it is natural that the surge voltage changes if the collector current of the IGBT provided in each functional unit changes. The control apparatus 100 which concerns on this invention estimates the surge voltage of IGBT in each function part according to the collector current of IGBT with which each function part is provided.

  In the above embodiment, it has been described that the driver 3 includes the bipolar transistors 3a and 3b, and the driver power supply unit 4 includes the bipolar transistor 4c. However, the scope of application of the present invention is not limited to this. For example, these bipolar transistors can naturally be constituted by IGBTs or MOS-FETs.

  In the above embodiment, the switching speed of the IGBT has been described as being increased according to the difference between the limit value and the drive voltage in each functional unit. However, the scope of application of the present invention is not limited to this. It is also possible to increase the switching speed by the following method.

  For example, when the control device 100 is configured to include the voltage converter 1 and the frequency converter 2, the first limit value in the voltage converter 1 and the second limit value in the frequency converter 2 are low. It is preferable to increase the switching speed of the IGBT of the voltage conversion unit 1 or the frequency conversion unit 2 having the higher limit value as the common limit value and the higher limit value according to the difference between the limit value and the common limit value. It is. With such a configuration, the switching speed is calculated based only on the first limit value, the second limit value, and the common limit value determined based on the element temperature of each switching element. Such a calculation processing load can be reduced. Of course, even when the frequency conversion unit 2 includes the first frequency conversion unit 21 and the second frequency conversion unit 22, it is naturally possible to increase the switching speed in the same manner.

  The present invention controls a rotating electrical machine comprising: a voltage converting unit that converts the output of a DC power source to generate a driving voltage; and a frequency converting unit that controls the rotating electrical machine and converts the driving voltage into an AC voltage. It can be used for the device.

The schematic diagram which showed roughly the structure of the control apparatus which concerns on this invention The figure which shows the functional composition of TCU Figure showing an example of a surge voltage map Figure showing an example of the device withstand voltage map The figure which shows the circuit constitution of the power supply for driver Diagram showing the circuit configuration of the driver Diagram showing surge voltage and switching loss at a given switching speed The figure which shows the surge voltage and switching loss when the switching speed of FIG. 7 is increased

Explanation of symbols

1: Voltage converters 1c, 1d: IGBT (first switching element)
2: Frequency converter 21: First frequency converter (frequency converter)
21a to 21f: IGBT (second switching element)
22: Second frequency converter (frequency converter)
22a to 22f: IGBT (third switching element)
3: Driver 4: Driver power supply 5: Element temperature detection unit 6: Current detection unit 7: Rotation angle detection unit 10: TCU
B1: High-voltage battery B2: Low-voltage battery 100: Control device (control device for rotating electrical machine)
MG1: Rotating electric machine MG2: Rotating electric machine

Claims (5)

A voltage converter that converts the output of the DC power source to generate a drive voltage;
A frequency converter that controls a rotating electrical machine and converts the drive voltage into an AC voltage;
A control device for a rotating electrical machine comprising:
A first limit value determining unit that determines a limit value of the drive voltage in the voltage conversion unit as a first limit value based on an element temperature of a first switching element included in the voltage conversion unit;
A second limit value determining unit that determines a limit value of the drive voltage in the frequency conversion unit as a second limit value based on the element temperature of the second switching element of the frequency conversion unit;
A common limit value determining unit that determines a lower limit value of the first limit value and the second limit value as a common limit value;
Bei to give a,
The switching speed of the switching element of the voltage conversion unit or the frequency conversion unit having the higher one of the first limit value and the second limit value as a limit value is the difference between the limit value and the common limit value. Rotating electric machine control device that speeds up according to . The first limit value is determined by subtracting an estimated value of a surge voltage generated according to a current flowing through the first switching element from an element withstand voltage determined according to an element temperature of the first switching element,
2. The second limit value is determined by subtracting an estimated value of a surge voltage generated according to a current flowing through the second switching element from an element breakdown voltage determined according to an element temperature of the second switching element. The control apparatus of the rotary electric machine as described in 2. The drive voltage is determined according to the target torque and the rotational speed of the rotating electrical machine,
The control device for a rotating electrical machine according to claim 1, wherein the voltage conversion unit limits the drive voltage to the common limit value or less. The rotation according to any one of claims 1 to 3, further comprising a driver that changes the switching speed by changing a voltage applied to a control resistor connected to a control terminal of the switching element or a resistance value of the control resistor. Electric control device. The rotating electrical machine is a first rotating electrical machine, and the frequency conversion unit that is controlled by the first rotating electrical machine is a first frequency converting unit,
In addition to the first rotating electrical machine, a second rotating electrical machine is provided, the second rotating electrical machine is a control target, the second frequency converting unit that converts the drive voltage into an AC voltage, and the second rotating electrical machine A third limit value determining unit that determines the limit value of the drive voltage in the second frequency conversion unit as a third limit value based on the element temperature of the third switching element included in the frequency conversion unit; ,
It said common limit value determining unit, the first limit value, the second limit value, and to any one of claims 1 to 4 for determining the lowest limit value of the third limit value as the common limit value The control apparatus of the rotary electric machine described.

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