JP2015177646A - Controller for rotary electric machine and rotary electric machine control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller and a control system capable of improving power generation efficiency of a rotary electric machine.SOLUTION: A vehicle comprises an engine 100, a power generator 200, and a motor 300. The power generator 200 is constituted by a variable-field rotary electric machine that comprises a main rotor and a sub rotor capable of relatively rotating along a rotation axis and changes a field magnetic flux by changing a phase angle between both rotors. An ECU 500 controls the phase angle between both rotors to increase/decrease the field magnetic flux of the power generator 200 depending on the engine 100's operation state. The ECU 500 minimizes the field magnetic flux to suppress a drag loss of the power generator 200 in an engine stop state; and maximizes the field magnetic flux in an engine operation state.

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 electric machine, wherein the rotating electric machine is connected to a crankshaft of an engine and generates electric power by the power of the engine. A first rotor element and a second rotor element that are arranged to face the stator and are arranged to face each other in the rotation axis direction, and the second rotor element is a rotor that is rotatable relative to the first rotor element. And switching means for switching the target field flux of the rotating electrical machine to either the maximum field flux or the minimum field flux based on the operation situation, at least input means for inputting the operation situation of the engine And control means for outputting a control command for controlling a phase angle of the second rotor element with respect to the first rotor element based on the target field magnetic flux. It is characterized in.

  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 calculating 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 the target field magnetic flux 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, and the rotating electrical machine is connected to an engine crankshaft and is driven by the power of the engine. The power generation unit includes a stator, and a first rotor element and a second rotor element that are arranged to face the stator and are arranged to face each other in the rotation axis direction, and the second rotor element is the first rotor element The control device is configured to input at least an operation state of the engine and input a target field flux of the rotating electrical machine based on the operation state to a maximum field flux or Switching means for switching to any one of the minimum field magnetic flux and for controlling the phase angle of the second rotor element with respect to the first rotor element based on the target field magnetic flux And a controlling means for outputting a control command.

  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 in accordance with the operating state of the engine. Thereby, the fuel consumption of the vehicle can be improved.

1 is a system configuration diagram of a hybrid vehicle. It is a basic lineblock diagram of the generator of an embodiment. It is AA sectional drawing of FIG. It is a perspective view which shows the phase relationship of a main rotor and a subrotor. It is a functional block diagram of ECU of embodiment. It is a timing chart of engine speed, engine torque, generator torque, and field magnetic flux. It is a timing chart of engine speed, engine torque, generator torque, and field magnetic flux.

  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). A specific configuration of the generator 200 will be described later.

  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. (Magnetic flux) is switched and controlled. ECU 500 operates in cooperation with a hybrid ECU that controls the entire hybrid vehicle.

  2 and 3 show a basic configuration of a generator 200 as a rotating electrical machine in the present embodiment. FIG. 2 shows a cross-sectional view seen from a direction orthogonal to the rotation axis direction of the generator 200, and FIG. 3 shows a view corresponding to the AA cross-section of FIG.

  The generator 200 includes a stator 24 fixed to a casing, and a rotor 28 that faces the stator 24 with a predetermined gap in the radial direction and is rotatable relative to the stator 24. In the example of FIG. 2, the rotor 28 is disposed to face the stator 24 at a position on the inner peripheral side of the stator 24.

  The stator 24 includes a stator core 36 and three-phase stator coils 38u, 38v, and 38w of U phase, V phase, and W phase, which are a plurality of phases disposed on the stator core 36 along the circumferential direction thereof. When a three-phase alternating current flows through the three-phase stator coils 38u, 38v, and 38w, a rotating magnetic field that rotates in the circumferential direction of the stator is generated.

  The rotor 28 includes a main rotor (first rotor element) 40 and a sub-rotor (second rotor element) 42 which are disposed to face the stator 24 in the radial direction in a state adjacent to the rotation axis direction. The main rotor 40 and the sub-rotor 42 are arranged to face each other with a gap in the rotation axis direction. In FIG. 2, the main rotor 40 is disposed on one side (left side in the drawing) in the rotation axis direction from the sub-rotor 42, the main rotor 40 is radially opposed to one side in the rotation axis direction of the stator core 36, and the sub-rotor 42 is It faces the other side (right side in the drawing) of the stator core 36 in the radial direction.

  The main rotor 40 includes a main rotor core 46 in which a plurality of electromagnetic steel plates are stacked in the rotation axis direction, and a plurality of main permanent magnets 48n and 48s disposed on the main rotor core 46 at equal intervals along the circumferential direction. . In FIG. 3, the main permanent magnets 48 n and 48 s of the main rotor 40 are shown through. In FIG. 3, the main permanent magnets 48 n and 48 s are embedded in a V shape as a pair at a plurality of positions in the circumferential direction of the main rotor core 46, but are not limited thereto. The main permanent magnet 48n has an N pole on the outer peripheral side, and the main permanent magnet 48s has an S pole on the outer peripheral side. Since the main permanent magnets 48n and 48s are alternately arranged in the circumferential direction, the polarities of the main permanent magnets 48n and 48s are alternately different in the circumferential direction.

  The sub-rotor 42 includes a sub-rotor core 54 in which a plurality of electromagnetic steel plates are stacked in the rotation axis direction, and a plurality of sub-permanent magnets 56n and 56s disposed on the sub-rotor core 54 at equal intervals along the circumferential direction. . The sub permanent magnets 56n and 56s are embedded in a V shape as a pair at a plurality of positions in the circumferential direction of the sub rotor core 54, but are not limited thereto. The auxiliary permanent magnet 56n has an N pole on the outer peripheral side, and the auxiliary permanent magnet 56s has an S pole on the outer peripheral side. Since the secondary permanent magnets 56n and 56s are alternately arranged in the circumferential direction, the polarities of the secondary permanent magnets 56n and 56s are alternately different in the circumferential direction. The circumferential interval between the secondary permanent magnets 56n and 56s is equal to the circumferential interval between the main permanent magnets 48n and 48s.

  Restraint plates 61 and 62 are fixed to the main rotor shaft 26 by welding or the like. The restraint plates 61 and 62 are arranged at intervals in the rotational axis direction, the restraint plate 62 is disposed on one side of the restraint plate 61 in the rotational axis direction, and the main rotor 40 is disposed on the restraint plates 61 and 62 in the rotational axis direction. Sandwiched between. The main rotor 40 is engaged with the main rotor shaft 26 by a keyway, a spline, or the like, and rotates integrally with the main rotor shaft 26 and the restraining plates 61 and 62.

  Restraint plates 63 and 64 are fixed to the sub-rotor shaft 52 by welding or the like. The restraint plates 63 and 64 are arranged at a distance from each other in the rotational axis direction, the restraint plate 63 is disposed on one side of the restraint plate 64 in the rotational axis direction, and the auxiliary rotor 42 is disposed on the restraint plates 63 and 64 in the rotational axis direction. Sandwiched between. The sub-rotor 42 is engaged with the sub-rotor shaft 52 by a keyway, a spline, or the like, and rotates integrally with the sub-rotor shaft 52 and the restraining plates 62 and 63. The auxiliary rotor shaft 52 is supported by the bearing 50 so as to be rotatable relative to the main rotor shaft 26, and the auxiliary rotor 42 is rotatable relative to the main rotor 40.

  In the rotating electrical machine of the present embodiment, the field magnetic flux of the rotor 28 acting on the stator 24 is changed by changing the phase relationship between the main rotor 40 and the sub-rotor 42. When the main rotor 40 and the sub rotor 42 have the same polarity of the main permanent magnet 48n and the sub permanent magnet 56n (or the main permanent magnet 48s and the sub permanent magnet 56s) arranged in the same phase in the circumferential direction, Magnetic flux is maximized. On the other hand, when the sub-rotor 42 is rotated relative to the main rotor 40 and the main permanent magnet 48n and the sub-permanent magnet 56n (or the main permanent magnet 48s and the sub-permanent magnet 56s) are opposed to each other by 180 degrees, Magnetic flux is minimal or zero.

  FIG. 4 is a perspective view showing only the main rotor 40 and the sub-rotor 42 taken out. FIG. 4A shows a state where the main rotor 40 and the sub-rotor 42 are in the same pole facing state, and γ = 0 degrees (deg) when the phase angle is γ. At this time, the field magnetic flux of the rotor 28 acting on the stator 24 is maximized. FIG. 4B shows a state in which the main rotor 40 and the sub-rotor 42 are opposite to each other and γ = 180 degrees (deg). At this time, the field magnetic flux of the rotor 28 acting on the stator 24 is minimized. As described above, the generator 200 according to the present embodiment changes the phase relationship between the main rotor 40 and the sub-rotor 42, that is, changes the phase angle γ by relatively rotating the main rotor 40 and the sub-rotor 42 to the stator 24. It functions as a variable field type rotating electrical machine that changes the field magnetic flux of the acting rotor 28. In this embodiment, the phase angle is controlled to either γ = 0 degrees or γ = 180 degrees, and the field magnetic flux is switched to either maximum or minimum.

  FIG. 5 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 generator torque control unit 506, and a phase angle control unit 510 as functional blocks.

The target field characteristic switching unit 502 of the generator sets the target field characteristic (target field magnetic flux) of the generator 200 according to the engine state (engine operation / stop). That is, the target field characteristic switching unit 502 of the generator sets the field characteristics 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. In the above equation, 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. The generator target field characteristic switching unit 502 outputs the set target field characteristic (target field magnetic flux) to the phase angle control unit 510 and the generator torque control unit 506.

  Based on the target phase angle, the angle of the main rotor 40, and the angle of the sub-rotor 42, the phase angle control unit 510 has a current value necessary for shifting from the current phase angle of the main rotor 40 and the sub-rotor 42 to the target phase angle. Is calculated and output to the drive circuit. When the drive circuit is an actuator that mechanically rotates the sub-rotor 42 with respect to the main rotor 40, a current command is output to the actuator. The sub-rotor 42 can be rotated relative to the main rotor 40 by the stator current without using an actuator as a drive circuit. In this case, the phase angle control unit 510 generates torque in a direction in which the main rotor 40 and the sub-rotor 42 are rotated in directions opposite to each other, and generates a torque that does not contribute to rotation for the entire rotor 28. Vector calculation of current.

  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.

  FIG. 6 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 magnetic flux of the generator 200 according to the present embodiment.

  FIG. 6A shows the number of revolutions of the engine 100. The engine 100 sequentially changes to engine stop, engine cranking, engine operation, and engine stop states as time passes. 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. 6B shows the torque of the engine 100. The torque is zero when the engine is stopped and when the engine is cranked. The engine torque varies depending on the driver's accelerator operation and battery SOC during 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 ECU 500.

  FIG. 6C shows the torque of the generator 200, and FIG. 6D shows the field magnetic flux of the generator 200. The upward direction (positive direction) of the vertical axis in FIG. 6C indicates electric torque, and the downward direction (negative direction) indicates power generation torque. Further, the vertical axis of FIG. 6D shows the maximum value φmax of the field magnetic flux as 100% and the minimum value φmin as 0%. 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 magnetic flux of the generator 200 is set to 0% of the minimum 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 with the motor 300 (EV running mode).

  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 magnetic flux of the generator 200 is controlled to be switched to the maximum value φmax. This is because the field magnetic flux is increased to suppress the torque current in the generator 200 and drive efficiently as a motor. 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 ECU 500 controls the torque of the generator 200 in order 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 increase, the field magnetic flux is set to 100% accordingly. Thereby, the power generation efficiency in the generator 200 increases. Since the field magnetic flux is already set to 100% in the engine cranking state, it can be said that this field magnetic flux is maintained as it is even during engine operation after the engine is started.

  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 drag loss is minimized by setting the field magnetic flux of the generator 200 to the minimum value φmin (= 0%).

  In this way, the generator 200 can be efficiently operated by adaptively switching and controlling the field magnetic flux of the generator 200 according to the state of the engine 100, resulting in improved fuel efficiency. To do.

  In the timing chart of FIG. 6, as shown in FIG. 6D, the field magnetic flux of the generator 200 is changed from the minimum value φmin (= 0%) to the maximum value φmax (= 100%) simultaneously with the start of engine cranking. Therefore, it takes time to start the engine 100. Therefore, the field magnetic flux of the generator 200 may be switched earlier in order to start the engine 100 earlier.

  FIG. 7 shows another timing chart. What is different from FIG. 6 is the time variation of the field current during engine cranking. That is, in FIG. 6D, the field magnetic flux is increased to 100% simultaneously with the start of engine cranking. In FIG. 7D, the field magnetic flux is set to 100% before the cranking start timing. Later, 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.

  As described above, the field magnetic flux of the generator 200 is switched between the maximum value φmax and the minimum value φmin so that the power generation efficiency of the generator 200 is increased, that is, the phases of the main rotor 40 and the sub-rotor 42. Since the angle is controlled to be switched between 0 degrees and 180 degrees, power can be generated with high efficiency by the power of the engine 100 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. In the present embodiment, a lock mechanism that locks the phase angle of the main rotor 40 and the sub-rotor 42 at either γ = 0 degrees or γ = 180 degrees may be provided.

  Further, in the present embodiment, as shown in FIG. 5, the target field characteristics are set based on the operating state of the engine, the target field magnetic flux is set to the minimum value φmin when the engine is stopped, and the engine cranking state and the engine are operating. Although 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, operation status, and generator temperature with higher accuracy. 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 ′. It goes without saying that the phase angle of the main rotor 40 and the sub-rotor 42 is also changed with the change of the field magnetic flux.

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 a crankshaft of an engine and generates electric power by the power of the engine.
A stator, and a first rotor element and a second rotor element that are arranged to face the stator and are arranged to face each other in the rotation axis direction, and the second rotor element is rotatable relative to the first rotor element A rotor and
Configured with
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 a phase angle of the second rotor element with respect to the first rotor element 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 electric machine wherein the minimum field magnetic flux is the target field magnetic flux when the engine is stopped and the maximum field magnetic flux is 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 device of the rotating electrical machine, wherein the control means controls the field magnetic flux of the rotating electrical machine to the target field magnetic flux prior to the start of cranking of the engine. A variable field type rotating electrical machine,
A control device for controlling the rotating electrical machine;
With
The rotating electrical machine is connected to a crankshaft of an engine and generates electric power by the power of the engine, and a stator, a first rotor element disposed opposite to the stator and disposed opposite to each other in the direction of the rotation axis, and A second rotor element, the second rotor element being rotatable relative to the first rotor element;
With
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 a phase angle of the second rotor element with respect to the first rotor element 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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