JP6349846B2 - Rotating electrical machine control device and rotating electrical machine control system - Google Patents

Description

  The present invention relates to a control device for a variable field type rotating electrical machine and a rotating electrical machine control system.

  In Patent Document 1 below, a rotor of a motor generator includes an inner rotor having a permanent magnet and an outer rotor having a permanent magnet and arranged to be relatively rotatable outside the inner rotor. And the induced voltage constant can be changed by manipulating the rotational phase of both rotors. The engine drive target torque is changed according to the change of the induced voltage constant to balance the power generation torque and the output torque.

JP 2008-94182 A

  However, the conventional technology does not sufficiently consider the loss generated in the generator, and there is a problem that the power generation efficiency is not necessarily high. For example, when the engine and the generator are directly connected as in a general series hybrid configuration, the generator is always stopped when the engine is stopped, so there is no need to consider drag loss when the engine is stopped. In a hybrid vehicle or the like having a configuration as shown in FIG. 1, a generator is driven when the vehicle travels with the engine stopped. For this reason, when the engine is stopped, the dragging loss of the generator is suppressed, and when the engine is cranked and started by the generator, the generator functions as a motor to increase its torque. In order to control the generator torque from moment to moment according to the situation, it is necessary to dynamically change the induced voltage constant. Not considered.

  The objective of this invention is providing the control apparatus and rotary electric machine control system of a rotary electric machine which can further improve the electric power generation efficiency of a rotary electric machine.

  The present invention is a control device for controlling a variable field type rotating electrical machine, wherein the rotating electrical machine is connected to a crankshaft of an engine and generates electric power by the power of the engine, and at least the operating state of the engine Input means for inputting, switching means for switching the target field magnetic flux of the rotating electrical machine to either the maximum field magnetic flux or the minimum field magnetic flux based on the operating state, and the rotating electrical machine based on the target field magnetic flux Control means for outputting a control command for controlling the field magnetic flux to the target field magnetic flux.

  In one embodiment of the present invention, the switching means uses the minimum field magnetic flux as the target field magnetic flux when the engine is stopped and the maximum field magnetic flux as the target field magnetic flux when the engine is operating. It is characterized by that.

  In another embodiment of the present invention, the switching means sets the maximum field magnetic flux as the target field magnetic flux in the cranking state of the engine.

  In still another embodiment of the present invention, the control means controls the field magnetic flux of the rotating electrical machine to a maximum value prior to the start of cranking of the engine.

  The rotating electrical machine control system of the present invention includes a variable field type rotating electrical machine and a control device that controls the rotating electrical machine, the rotating electrical machine being connected to an engine crankshaft, and generating electric power by the engine power. The control device includes at least an input means for inputting an operating state of the engine, and based on the operating state, the target field magnetic flux of the rotating electrical machine is either a maximum field magnetic flux or a minimum field magnetic flux. And a control means for outputting a control command for controlling the field magnetic flux of the rotating electrical machine to the target field magnetic flux based on the target field magnetic flux.

  The rotating electrical machine control system of the present invention can be mounted on a vehicle such as a hybrid vehicle that runs on an engine and the rotating electrical machine.

  According to the present invention, the power generation efficiency of the rotating electrical machine can be further improved according to the driving situation of the mounted vehicle. Thereby, the fuel consumption of the vehicle can be improved.

1 is a system configuration diagram of a hybrid vehicle. It is a functional block diagram of ECU of embodiment. It is a functional block diagram of ECU of other embodiment. It is a graph which shows the relationship between a field current and a field magnetic flux. It is a timing chart of engine speed, engine torque, generator torque, and field current. It is a timing chart of engine speed, engine torque, generator torque, and field current. It is a functional block diagram of ECU of other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of a hybrid vehicle equipped with a variable field type rotating electrical machine. A generator 200 and a motor 300 are mounted as rotating electric machines. The generator 200 is connected to the crankshaft of the engine 100 via a planetary gear. The motor 300 is also connected to the planetary gear. The output shaft of the planetary gear is connected to a tire (drive wheel) 400 via a differential gear. The generator 200 and the motor 300 are each electrically connected to a battery (not shown), and power is transmitted and received. The generator 200 generates power using the power of the engine 100 and supplies the generated power to the motor 300 and the battery. The motor 300 generates a driving force for driving using the power from the battery and the power from the generator to drive the tire 400.

  The engine 100, the generator 200, the motor 300, and the tire 400 are connected by a power distribution mechanism, and change the output characteristics of the driving force for driving with respect to the accelerator operation amount according to the driving state of the vehicle. Is selectively switched between a mode for generating the power (EV traveling mode) and a mode for generating the driving force in both the motor 300 and the engine 100.

  At least the generator 200 of the generator 200 and the motor 300 is a variable field type rotating electric machine, and is a rotating electric machine with variable field magnetic flux (linkage magnetic flux of the stator). There are various types of variable field type rotating electrical machines, but any corresponding variable field type rotating electrical machine can be used in the present embodiment. For example, the rotor is composed of an inner rotor having a permanent magnet and an outer rotor having a permanent magnet and capable of rotating relative to the outside of the inner rotor, and the rotational phase of both rotors is operated by a rotation operation mechanism. The field magnetic flux may be variable. Alternatively, it includes a main rotor and a sub-rotor that are arranged radially opposite to the stator in a state adjacent to the rotation axis direction, and the main rotor and the sub-rotor are arranged to face each other with a gap in the rotation axis direction, and the sub-rotor is arranged as the main rotor As a configuration that allows relative rotation, the rotational phase of the sub-rotor may be manipulated by a rotational operation mechanism or a stator current to make the field magnetic flux variable.

  The electronic control unit (ECU) 500 includes a microcomputer including a CPU and a memory, and controls the generator 200 and the motor 300 by inputting various detection signals. In particular, the ECU 500 controls the field magnetic flux (stator linkage) so that the power generation efficiency of the generator 200 increases in accordance with the driving state of the hybrid vehicle, specifically, the engine 100 stop, cranking, and driving states. Varying the magnetic flux. ECU 500 operates in cooperation with a hybrid ECU that controls the entire hybrid vehicle, which will be described later.

  FIG. 2 shows a functional block diagram of ECU 500. 3 is a functional block diagram for controlling a generator 200. FIG.

  The ECU 500 includes a generator target field characteristic switching unit 502, a field characteristic control unit 504, and a generator torque control unit 506 as functional blocks.

The target field characteristic switching unit 502 of the generator is configured to generate a target field characteristic (target field magnetic flux) of the generator 200 necessary for outputting a required torque in accordance with an engine state (engine operation / stop) as an operation state. ). That is, the target field characteristic switching unit 502 of the generator switches the field characteristic between the maximum value and the minimum value based on the engine state supplied from the hybrid ECU. Assuming that the power generation amount of the generator 200 is W, the required torque of the generator 200 is T, the angular velocity (number of rotations) of the generator 200 is ω, and the field magnetic flux (linkage flux of the stator) is φ, the torque T is the field Since the loss Q of the generator 200 depends on the required torque T, the field magnetic flux φ, and the angular velocity ω, the power generation model is generally W = T (φ, ω) ω−Q (T (Φ, ω), φ, ω)
It can be expressed as. The field magnetic flux φ is set to two values of the minimum values φmin and φmax, and is switched to either φmax or φmin so that the power generation amount W increases. The required torque T is set according to the remaining capacity (SOC) of the battery. Since the required torque T and the angular velocity ω are input and given, it can be said that the field magnetic flux φ in which W increases is inversely calculated using the power generation amount model. In the above equation, for example, when the engine is stopped and the required torque is zero, the field magnetic flux φ is set to the minimum value φmin so as to minimize the loss Q. When the engine is in an operating state and the required torque increases, the field magnetic flux φ is set to the maximum value φmax. T (φ, ω) and Q (T (φ, ω), φ, ω) are determined in advance by experiment or simulation or the like and stored in the memory. As an example, the correspondence between the engine state and the field magnetic flux is stored in a memory as a table, and the field magnetic flux is read with reference to the table. The generator target field characteristic switching unit 502 outputs the set target field characteristic (target field magnetic flux) to the field characteristic control unit 504 and the generator torque control unit 506.

  The field characteristic control unit 504 outputs a characteristic adjustment command to a field characteristic adjustment mechanism for changing the field magnetic flux based on the calculated target field characteristic (target field magnetic flux). If the field characteristic adjusting mechanism is a rotational operation mechanism that rotates the outer peripheral rotor relative to the inner peripheral rotor, the control command is for driving the mechanism.

  The generator torque control unit 506 calculates a voltage that satisfies the required torque while satisfying the target field characteristics based on the required torque, angular velocity (rotation speed), stator current, and target field characteristics, This is supplied to an inverter that supplies a three-phase alternating current to the V-phase and W-phase three-phase stator coils. If the target field characteristic is fixed, the generator torque control unit 506 simply calculates a voltage satisfying the required torque and outputs it to the inverter. In this embodiment, the target field characteristic has the maximum value φmax and the minimum value φmin. Therefore, the voltage value output to the inverter also changes accordingly. That is, the control parameter for generating power with the generator 200 is adaptively changed depending on the target field characteristics for increasing the power generation efficiency.

  Next, this embodiment will be described more specifically. As a configuration of the generator 200, a variable field type rotating electrical machine described in, for example, Japanese Patent Application Laid-Open No. 2010-226808 will be described as an example.

  In this rotating electrical machine, the rotor is composed of a radial rotor and an axial rotor. The axial rotor is mechanically and magnetically coupled to the radial rotor. The stator has an annular core portion, a field winding that generates a field magnetic flux that passes through the radial rotor, the axial rotor, and the annular core portion when a direct current flows, and a toroidal winding around the annular core portion to cause an alternating current to flow. It has an armature winding that generates a magnetic field that interacts with the field flux. The radial rotor has a radial magnetic pole portion that is magnetized when a direct current flows through the field winding, and a radial permanent magnet that is arranged so as to be shifted with respect to the radial magnetic pole portion. The axial rotor is arranged so as to be shifted from the radial magnetic pole portion with respect to the circumferential direction around the rotation axis, and an axial magnetic pole portion that is magnetized in a polarity opposite to that of the radial magnetic pole portion when a direct current flows through the field winding, and the axial magnetic pole portion, It has an axial permanent magnet which is arranged to be shifted with respect to the radial permanent magnet and has a polarity opposite to that of the radial permanent magnet.

  By applying a direct current to the field winding so that the radial magnetic pole part is magnetized in the opposite polarity to the radial permanent magnet and the axial magnetic pole part is magnetized in the opposite polarity to the axial permanent magnet, the field magnetic flux (interlinkage magnetic flux of the stator) ) Increases. In addition, by applying a direct current to the field winding so that the radial magnetic pole part is magnetized with the same polarity as the radial permanent magnet and the axial magnetic pole part is magnetized with the same polarity as the axial permanent magnet, ) Decreases. Therefore, the amount of field magnetic flux can be varied by controlling the direction and magnitude of the direct current flowing through the field winding.

  Instead of arranging the radial rotor inside the stator in the radial direction, the radial rotor may be arranged outside the stator in the radial direction. Moreover, you may arrange | position a radial rotor in the radial inside and radial outside of a stator. Further, the axial rotor may be composed of one rotor, or may be composed of two axial rotors adjacent in the rotation axis direction.

  FIG. 3 shows a functional block diagram of the ECU 500 in the present embodiment. The difference from FIG. 2 is that a target field current generation unit 508 and a field current control unit 510 are provided instead of the field characteristic control unit 504.

  The target field current generation unit 508 generates a target field current Ifref so as to achieve the target field characteristics calculated by the target field characteristic switching unit 502 of the generator, and outputs the target field current Ifref to the field current control unit 510. The target field current generation unit 508 determines the direction and magnitude of the field current Ifref that obtains the target field characteristics based on a predetermined relationship between the direction and magnitude of the direct current flowing through the field winding and the field magnetic flux. Calculate.

  FIG. 4 shows the relationship between the field current and the field magnetic flux in the present embodiment. In the figure, the energizing direction is such that the radial magnetic pole part is magnetized in the opposite polarity to the radial permanent magnet, the axial magnetic pole part is magnetized in the opposite polarity to the axial permanent magnet, and the radial magnetic pole part is magnetized in the same polarity as the radial permanent magnet. An energizing direction in which the axial magnetic pole portion is magnetized to the same polarity as the axial permanent magnet is defined as negative. With the field current If = 0 as a boundary, when the field current increases in the positive direction, the field magnetic flux increases correspondingly and reaches the maximum value φmax. Further, when the field current increases in the negative direction, the field magnetic flux decreases correspondingly and becomes the minimum value φmin. The target field current generation unit 508 stores the correspondence shown in FIG. 4 in a memory as a map or function, and calculates a field current Ifref corresponding to the calculated target field characteristic (target field magnetic flux). To the field current control unit 510. In this embodiment, since either the maximum value φmax or the minimum value φmin is used as the field magnetic flux, the field current corresponding to these is stored in the memory as a map. Of course, since the field magnetic flux is one of the maximum value φmax and the minimum value φmin, it may be easily switched without using a map.

  The field current control unit 510 feedback-controls the current field current so that the calculated target field current Ifref flows, and outputs a control command to the field current drive circuit. The field current drive circuit is composed of, for example, a DC / DC converter including two switching arms connected in parallel to each other between a positive terminal and a negative terminal of a battery, and a midpoint of each of the two switching arms. A field winding is connected between the two. By controlling on / off the switching elements of the two switching arms, a desired positive or negative direct current can be passed through the field winding.

  FIG. 5 is a timing chart of the rotational speed of the engine 100, the torque of the engine 100, the torque of the generator 200, and the field current of the generator 200 according to the present embodiment.

  FIG. 5A shows the number of revolutions of the engine 100, which sequentially transitions to each of the engine stop, engine cranking, engine operation, and engine stop states as time elapses. In the engine cranking state, the engine speed increases, and in the engine operating state, the engine speed increases or decreases according to the driver's accelerator operation and the remaining battery capacity (SOC). When the engine is stopped, the engine speed decreases and eventually becomes zero.

  FIG. 5B shows the torque of the engine 100. The torque is zero in each of the engine stop state and the engine cranking state, and the engine torque varies according to the driver's accelerator operation and the battery SOC during the engine operation. To do. When the engine is stopped, the torque becomes zero again. The required torque for engine 100 is calculated by a hybrid ECU that controls the entire hybrid vehicle. When the hybrid ECU determines that power generation is necessary based on the SOC of the battery, the hybrid ECU outputs a power generation command to the ECU 500.

  5C shows the torque of the generator 200, and FIG. 5D shows the field current of the generator 200. The upward direction (positive direction) of the vertical axis in FIG. 5C indicates electric torque, and the downward direction (negative direction) indicates power generation torque. Further, the vertical axis of FIG. 5D represents the field current at which the field magnetic flux becomes the maximum value φmax as 100%. When the engine is stopped, the engine speed and the engine torque are zero, and the torque of the generator 200 is also zero. At this time, the field current Ifref of the generator 200 takes a negative value. This is for minimizing drag loss (iron loss) in the generator 200 by minimizing the field magnetic flux of the generator 200 when the hybrid vehicle runs only by the motor 300 (EV running mode). This is based on the fact that the field magnetic flux becomes the minimum value φmin when the field current is a negative maximum current.

  When transitioning from the engine stop state to the engine cranking state, the generator 100 connected to the crankshaft of the engine 100 is caused to function as a motor to crank the engine 100. That is, a torque command is output from the hybrid ECU to the ECU 500, and the ECU 500 causes the generator 200 to function as a motor. For this reason, the electric torque of the generator 200 also increases. At this time, the field current Ifref of the generator 200 is set to 100% at which the maximum value φmax of the field magnetic flux can be obtained. This is because the field magnetic flux is increased to suppress the drive current in the generator 200 and drive efficiently as a motor. If the engine cranking is successful, the engine 100 starts and the engine speed and engine torque begin to increase. When the engine cranking is completed, the torque of the generator 200 becomes zero again to prepare for power generation.

  When transitioning from the engine cranking state to the engine operating state, the torque of the generator 200 is controlled to generate power using the power of the engine 100. Specifically, the hybrid ECU calculates the battery required power as the power to be charged by the battery based on the SOC of the battery, and sets the engine required power to be output from the engine 100 based on the battery required power. Then, the target rotational speed and target torque of engine 100 are set based on the engine required power, and the target rotational speed of generator 200 is set based on the target rotational speed of engine 100. Furthermore, the required torque of the generator 200 is set based on the target rotation speed of the generator 200 and the current rotation speed. When the engine torque and the generator torque are increased, the field current Ifref is set to 100% and the field magnetic flux is set to the maximum value φmax. Thereby, the power generation efficiency in the generator 200 increases. Since the field current is already set to 100% in the engine cranking state, it can be said that this field current is maintained as it is even during engine operation after engine startup.

  When transitioning from the engine operation state to the engine stop state again, the engine speed and the engine torque become zero, and the torque of the generator 200 also becomes zero. At this time, the field current Ifref of the generator 200 again becomes a negative value, and the field flux is set to the minimum value φmin to minimize the drag loss.

  Thus, according to the state of the engine 100, the field magnetic flux of the generator 200 is adaptively controlled to increase the power generation efficiency, whereby the generator 200 can be efficiently operated, and as a result, the fuel efficiency is improved. .

  In the timing chart of FIG. 5, as shown in FIG. 5 (d), the field current of the generator 200 is increased from a negative value simultaneously with the start of engine cranking, and the field magnetic flux is changed from the minimum value φmin to the maximum value. Since it is switched to φmax, it takes time to start the engine 100. Therefore, the field magnetic flux of the generator 200 may be increased earlier in order to speed up the start of the engine 100.

  FIG. 6 shows another timing chart. What is different from FIG. 5 is the time variation of the field current during engine cranking. That is, in FIG. 5D, the field current is increased to 100% simultaneously with the start of engine cranking. In FIG. 6D, the field current starts to increase before the cranking start timing. After the field current reaches 100%, the generator torque is output and cranking is performed. In short, instead of changing the field magnetic flux simultaneously with the start of engine cranking, engine cranking is performed after the field magnetic flux reaches the maximum value φmax. Thereby, engine 100 can be started quickly.

  In this embodiment, the generator torque control unit 506 of the ECU 500 controls the control parameters of the generator 200, specifically the voltage value of the inverter, according to the calculated target field characteristics. The target field characteristics may be simply estimated separately from the target field characteristic switching unit 502 of the machine, and the control parameters of the generator 200 may be controlled according to the estimated target field characteristics.

  FIG. 7 shows another functional block diagram of ECU 500. The difference from FIG. 3 is that a field characteristic estimation unit 512 is provided separately from the target field characteristic switching unit 502 of the generator to estimate whether the target field characteristic is the maximum value φmax or the minimum value φmin. And output to the generator torque control unit 506.

  The field characteristic estimation unit 512 estimates target field characteristics based on the angular velocity, the stator current, and the voltage command value of the generator 200 and outputs them to the generator torque control unit 506. Specifically, when the rotor of the generator 200 is composed of a main rotor and a sub rotor adjacent to each other in the rotation axis direction, and the sub rotor is rotated by a stator current when the sub rotor is rotated relative to the main rotor, the stator is Since the current component for torque and the current component for relative rotation are superimposed on the current, the target field characteristics can be estimated by detecting the stator current. Specifically, when the field current is set to a negative value so that the field magnetic flux becomes the minimum value φmin when the engine is stopped, a negative field current is superimposed on the stator current. The magnetic characteristic estimation unit 512 can estimate that the target field characteristic is the minimum value φmin by detecting the stator current. The subsequent steps are the same as in FIG.

  As described above, the field magnetic flux of the generator 200 is adaptively switched between the maximum value φmax and the minimum value φmin so that the power generation efficiency of the generator 200 is increased. Power can be generated with efficiency to charge the battery, or power can be supplied to the motor 300. In particular, when the engine is stopped, the field magnetic flux can be set to the minimum value φmin to minimize the loss in the generator 200, and in the engine operating state, the field magnetic flux can be set to the maximum value φmax to increase the power generation efficiency of the generator 200.

  In this embodiment, since the field magnetic flux of the generator 200 is controlled to either the maximum value φmax or φmin, there is an advantage that the control is simplified.

  Further, in the present embodiment, as shown in FIG. 2 and the like, the target field characteristics are switched based only on the engine operating state, the target field magnetic flux is set to the minimum value φmin when the engine is stopped, the engine cranking state and the engine operation While the target field magnetic flux is set to the maximum value φmax, the target field characteristics may be set based on the required torque, angular velocity, voltage, operating condition, and generator temperature. In this case, the voltage and temperature parameters may be reflected in a table (or map) and stored in the memory of the ECU 500. For example, even when the engine is operating, it is not necessary to generate power with the generator 200, and if the required torque is zero, the field magnetic flux is switched to the minimum value φmin. Depending on the voltage and temperature, the minimum value φmin of the field magnetic flux is changed to another minimum value φmin ′, or the maximum value φmax is changed to another maximum value φmax ′. The field magnetic flux of the generator 200 may be switched between the minimum value φmin ′ and the maximum value φmax ′.

100 engine, 200 rotating electric machine (generator), 300 rotating electric machine (motor), 400 tire, 500 electronic control unit (ECU).

Claims (6)

A control device for controlling a variable field type rotating electrical machine,
The rotating electrical machine is connected to an engine crankshaft and generates electric power by the engine power;
Input means for inputting at least the operating status of the engine;
Switching means for switching the target field magnetic flux of the rotating electrical machine to either the maximum field magnetic flux or the minimum field magnetic flux based on the operation status;
Control means for outputting a control command for controlling the field magnetic flux of the rotating electric machine to the target field magnetic flux based on the target field magnetic flux,
A control device for a rotating electrical machine comprising: The control apparatus for a rotating electrical machine according to claim 1,
The switching means controls the rotating electrical machine to use the minimum field magnetic flux as the target field magnetic flux when the engine is stopped and the maximum field magnetic flux as the target field magnetic flux when the engine is operating. apparatus. The control apparatus for a rotating electrical machine according to claim 2,
The control device for a rotating electrical machine, wherein the switching means sets a maximum field magnetic flux as the target field magnetic flux in a cranking state of the engine. The control apparatus for a rotating electrical machine according to claim 3,
The control unit controls a rotating electrical machine to a maximum field magnetic flux before the cranking of the engine is started. A variable field type rotating electrical machine,
A control device for controlling the rotating electrical machine;
With
The rotating electrical machine is connected to an engine crankshaft and generates electric power by the engine power;
The controller is
Input means for inputting at least the operating status of the engine;
Switching means for switching the target field magnetic flux of the rotating electrical machine to either the maximum field magnetic flux or the minimum field magnetic flux based on the operation status;
Control means for outputting a control command for controlling the field magnetic flux of the rotating electric machine to the target field magnetic flux based on the target field magnetic flux,
A rotating electrical machine control system comprising: A vehicle comprising the rotating electrical machine control system according to claim 5.

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