JP2020178446A - Modulation method changeover device - Google Patents

Abstract

To suppress a transient change of battery current in a modulation method changeover device that changes a modulation method when controlling a dual phase rotary electric machine driven by battery voltage.SOLUTION: A modulation method changeover device (60) has a first executing unit (61) executing a first modulation method in which applied voltage applied to each phase (34U, 34V, and 34W) of a dual phase rotary electric machine (30) is limited to equal to or less than a first upper limit voltage, a second executing unit (62) executing a second modulation method in which the applied voltage applied to each phase is limited to equal to or less than a second upper limit voltage higher than the first upper limit voltage, and a changeover unit (64) changing from the first modulation method to the second modulation method, based on a parameter correlated with induced voltage induced in each phase accompanied by a rotation of the dual phase rotary electric machine on condition that phase voltage that is the applied voltage from which the induced voltage is subtracted in the second modulation method executed by the second executing unit becomes lower than a predetermined voltage.SELECTED DRAWING: Figure 1

Description

The present invention relates to a modulation method switching device that switches a modulation method when controlling a multi-phase rotary electric machine.

Conventionally, in the pulse width modulation of a power converter, a modulation method is seamlessly performed according to the modulation rate (amplitude of voltage command value / amplitude of carrier wave) from 3-phase modulation to 2-phase modulation and overmodulation (1 pulse drive). There is a technology to switch (see Patent Document 1)

Japanese Unexamined Patent Publication No. 2017-21269

By the way, when the double-phase rotating electric machine is driven by the battery voltage applied from the battery, the battery current flowing from the battery fluctuates as the load of the double-phase rotating electric machine fluctuates. As the battery current fluctuates, the battery voltage fluctuates, which in turn fluctuates the modulation factor. Therefore, in the technique of Patent Document 1 in which the modulation method is switched according to the modulation rate, the modulation method may be improperly switched and the battery current may fluctuate transiently.

The present invention has been made to solve the above problems, and a main object thereof is transiently in a modulation method switching device for switching a modulation method when controlling a dual-phase rotary electric machine driven by a battery voltage. The purpose is to suppress fluctuations in the battery current.

The first means for solving the above problems is
A modulation method switching device (60) for switching a modulation method when controlling a double-phase rotary electric machine (30) driven by a battery voltage applied from a battery (20).
A first modulation method in which the applied voltage applied to each phase (34U, 34V, 34W, 34UA, 34VA, 34WA, 34UB, 34VB, 34WB) of the double-phase rotary electric machine is limited to the first upper limit voltage or less. The first execution unit (61) to be executed and
A second execution unit (62) that executes a second modulation method in which the applied voltage applied to each phase of the double-phase rotary electric machine is limited to a second upper limit voltage higher than the first upper limit voltage and lower.
In the second modulation method executed by the second execution unit, the induced voltage is derived from the applied voltage based on the parameters correlated with the induced voltage induced in each phase with the rotation of the double-phase rotating electric machine. A switching unit (64) for switching from the first modulation method to the second modulation method on condition that the subtracted phase voltage becomes lower than a predetermined voltage.
To be equipped.

According to the above configuration, the modulation method switching device switches the modulation method when controlling the dual-phase rotary electric machine driven by the battery voltage. The first execution unit executes the first modulation method, and the second execution unit executes the second modulation method. In the first modulation method, the applied voltage applied to each phase of the multi-phase rotary electric machine is limited to the first upper limit voltage or less. In the second modulation method, the applied voltage applied to each phase of the multi-phase rotary electric machine is limited to a second upper limit voltage higher than the first upper limit voltage. Therefore, the voltage applied to each phase by the second modulation method tends to be higher than the voltage applied to each phase by the first modulation method, and is transient when switching from the first modulation method to the second modulation method. Battery current may increase.

In this regard, the switching unit is charged from the applied voltage to the induced voltage in the second modulation method executed by the second execution unit based on the parameters that correlate with the induced voltage induced in each phase with the rotation of the double-phase rotating electric machine. The first modulation method is switched to the second modulation method on condition that the phase voltage obtained by subtracting is lower than the predetermined voltage. That is, the phase voltage obtained by subtracting the induced voltage from the applied voltage applied to each phase contributes to the increase in current. Therefore, by switching from the first modulation method to the second modulation method on condition that the phase voltage becomes lower than the predetermined voltage, it is possible to suppress the transient increase (fluctuation) of the battery current.

The induced voltage induced in each phase with the rotation of the double-phase rotating electric machine changes according to the rotational speed of the double-phase rotating electric machine and the magnetic flux density of the magnetic field.

In this regard, in the second means, the parameter includes the rotational speed of the dual-phase rotary electric machine. According to such a configuration, the first modulation method can be switched to the second modulation method based on the rotation speed of the double-phase rotary electric machine. Therefore, even if the induced voltage changes with the change in the rotation speed of the multi-phase rotating electric machine, it is accurately determined that the phase voltage becomes lower than the predetermined voltage, and the first modulation method is changed to the second modulation method. You can switch.

When the induced voltage induced in each phase increases with the rotation of the double-phase rotary electric machine, the maximum value of the torque that can be generated by the double-phase rotary electric machine decreases. Therefore, it is desirable to switch to a modulation method capable of generating a larger torque before the double-phase rotary electric machine cannot generate the required torque.

In this respect, in the third means, the switching unit is before the maximum value of the torque that can be generated by the double-phase rotary electric machine in the first modulation method executed by the first execution unit becomes smaller than the required torque. Further, on the condition that the above is true, the first modulation method is switched to the second modulation method. According to such a configuration, not only the transient increase in battery current is suppressed, but also the modulation method that can generate a larger torque is switched to before the double-phase rotating electric machine cannot generate the required torque. Can be done.

The induced voltage induced in each phase with the rotation of the double-phase rotary electric machine increases as the rotation speed of the double-phase rotary electric machine increases. Therefore, if hysteresis is provided in the rotation speed for switching from the first modulation method to the second modulation method and the rotation speed for switching from the second modulation method to the first modulation method, the second modulation method is used for the first modulation. The switching to the method may be delayed and the applied voltage may increase. In that case, the battery current may increase in the second modulation method.

In this regard, in the fourth means, the switching unit switches between the first modulation method and the second modulation method based on the rotation speed of the double-phase rotating electric machine, and the first modulation method to the second modulation method. The rotation speed for switching to the method and the rotation speed for switching from the second modulation method to the first modulation method are the same. According to such a configuration, it is possible to suppress the delay in switching from the second modulation method to the first modulation method, and it is possible to suppress an increase in the battery current in the second modulation method.

In the fifth means, the first execution unit controls the duty, which is the ratio of the time during which the battery voltage is applied to each phase in the predetermined cycle in the first modulation method, and sets the duty as the first upper limit duty. Limited to the following, the second execution unit controls the duty in the second modulation method, limits the duty to a second upper limit duty larger than the first upper limit duty, and the second execution unit is limited to the second upper limit duty or less. When the first modulation method is switched to the second modulation method, the Duty is limited to the third upper limit Duty or less, and the third upper limit Duty is gradually increased from the first upper limit Duty to the second upper limit Duty. Make it bigger.

According to the above configuration, the first execution unit controls the duty, which is the ratio of the time for applying the battery voltage to each phase in the predetermined cycle in the first modulation method, and limits the duty to the first upper limit duty or less. Therefore, in the first modulation method, the applied voltage can be limited to a voltage or less corresponding to the first upper limit duty. Further, the second execution unit controls the duty in the second modulation method, and limits the duty to a second upper limit duty that is larger than the first upper limit duty and less than or equal to the second upper limit duty. Therefore, in the second modulation method, the applied voltage can be limited to the voltage corresponding to the second upper limit duty or less. Here, since the second upper limit duty is larger than the first upper limit duty, the battery current may increase transiently when the first modulation method is switched to the second modulation method.

In this regard, the second execution unit limits the Duty to the third upper limit Duty or less when the first modulation method is switched to the second modulation method, and sets the third upper limit Duty from the first upper limit Duty to the second upper limit Duty. Gradually increase until. Therefore, when the first modulation method is switched to the second modulation method, it is possible to suppress a sudden increase in the applied voltage, and it is possible to suppress a transient increase in the battery current.

In the sixth means, the third execution of executing the third modulation method in which the applied voltage applied to each phase of the double-phase rotary electric machine is limited to the third upper limit voltage higher than the second upper limit voltage or less. The predetermined voltage includes a unit (63), the predetermined voltage is a first predetermined voltage, and the switching unit subtracts the induced voltage from the applied voltage applied to each phase by the third execution unit based on the parameter. The second modulation method is switched to the third modulation method on condition that the phase voltage becomes lower than the second predetermined voltage lower than the first predetermined voltage.

According to the above configuration, the third execution unit executes the third modulation method. In the third modulation method, the applied voltage applied to each phase of the multi-phase rotary electric machine is limited to the third upper limit voltage, which is higher than the second upper limit voltage. Therefore, the voltage applied to each phase by the third modulation method tends to be higher than the voltage applied to each phase by the second modulation method, and is transient when switching from the second modulation method to the third modulation method. Battery current may increase.

In this respect, in the switching unit, the phase voltage obtained by subtracting the induced voltage from the applied voltage applied to each phase by the third execution unit is lower than the second predetermined voltage, which is lower than the first predetermined voltage, based on the above parameters. On condition that, the second modulation method is switched to the third modulation method. Therefore, it is possible to suppress the transient increase (fluctuation) of the battery current. Further, since the modulation method switching device includes the third execution unit in addition to the first execution unit and the second execution unit, the applied voltage can be gradually increased. As a result, it is possible to further suppress the transient increase in battery current.

In the seventh means, when the rotation speed of the double-phase rotary electric machine is lower than the predetermined rotation speed, the switching unit applies a voltage applied to each phase by the second execution unit based on the parameters. On the condition that the phase voltage obtained by subtracting the induced voltage from the above is lower than the predetermined voltage, the first modulation method is switched to the second modulation method, and the rotation speed of the double-phase rotary electric machine is higher than the predetermined rotation speed. When it is high, the modulation method is switched based on the modulation rate of the command value of the applied voltage.

When the rotation speed of the double-phase rotary electric machine is lower than the predetermined rotation speed, for example, when the engine is started by the double-phase rotary electric machine, the battery current tends to increase rapidly, so it is desirable to suppress the rapid increase in the battery current. On the other hand, when the rotation speed of the double-phase rotary electric machine is higher than the predetermined rotation speed, for example, when the driving force of the engine is assisted by the double-phase rotary electric machine, it is desirable to suppress the fluctuation of the torque generated by the double-phase rotary electric machine. ..

In this regard, according to the above configuration, when the rotation speed of the dual-phase rotary electric machine is lower than the predetermined rotation speed, the first modulation method is switched to the second modulation method based on the parameter correlating with the induced voltage. Therefore, it is possible to suppress a rapid increase in battery current. On the other hand, when the rotation speed of the double-phase rotary electric machine is higher than the predetermined rotation speed, the modulation method is switched based on the modulation rate of the command value of the applied voltage. Therefore, it is possible to give priority to suppressing the fluctuation of the torque generated by the dual-phase rotary electric machine rather than suppressing the fluctuation of the battery current.

In the eighth means, when the detection unit that detects the battery current flowing from the battery and the state in which the battery current detected by the detection unit is larger than the predetermined current continues for a longer than a predetermined time, it is determined to be abnormal. A determination unit (66) is provided.

According to the above configuration, the determination unit determines that the battery current detected by the detection unit is abnormal when the state in which the battery current is larger than the predetermined current continues for a longer time than the predetermined time. In such a configuration, it is possible to suppress the transient increase in the battery current, so that it is possible to prevent the determination unit from erroneously determining an abnormality when switching the modulation method.

When the multi-phase rotary electric machine includes a plurality of systems having each of the above phases, if the modulation method is switched at the same time in the plurality of systems, the transient fluctuation of the battery current may be amplified.

In this respect, in the ninth means, the timing of switching the modulation method in the plurality of systems is different from each other. According to such a configuration, even when the multi-phase rotary electric machine includes a plurality of systems having each of the above phases, it is possible to suppress the amplification of transient fluctuations in the battery current.

The overall block diagram of the in-vehicle system which concerns on 1st Embodiment. The figure which shows the driving mode of the field energization circuit. The block diagram which shows the torque control when the rotation speed is equal to or less than the first rotation speed. The block diagram which shows the torque control when the rotation speed is higher than the third rotation speed. The figure which shows the switching mode of a modulation method. The figure which shows the definition of a voltage vector. A time chart showing a change mode of the upper limit duty. An equivalent circuit that describes the phase current. A graph showing the relationship between rotation speed and torque. The graph which shows the relationship between a rotation speed, a phase voltage, an induced voltage, and an applied voltage. A time chart showing a switching mode of a modulation method. The block diagram which shows a part of the in-vehicle system which concerns on 2nd Embodiment. The figure which shows the spatial phase difference of the 1st and 2nd stator winding group. The figure which shows the driving mode of the switch using 120 ° energization.

<First Embodiment>
Hereinafter, the first embodiment embodied in the rotary electric machine and the modulation method switching device mounted on the vehicle will be described with reference to the drawings.

As shown in FIG. 1, the vehicle includes an engine 10 as an in-vehicle main engine. The engine 10 is provided with a fuel injection valve or the like, and generates power by burning fuel such as gasoline or light oil injected from the fuel injection valve. The generated power is output from the output shaft 10a of the engine 10.

The vehicle includes a battery 20 as a DC power source, a load 22, and a control system. The battery 20 is, for example, a lithium storage battery having a rated voltage of 12 V, a lead storage battery, or the like. The control system includes an AC-driven rotary electric machine 30. In this embodiment, a field winding type synchronous machine is used as the rotary electric machine 30 (double-phase rotary electric machine). Further, in the present embodiment, an ISG (Integrated Starter Generator), which is a generator to which the function of an electric motor is added, is used as the rotary electric machine 30. The rotary electric machine 30 is, for example, a salient pole machine.

The rotary electric machine 30 includes a rotor 31. The rotor 31 includes a field winding 32. The rotating shaft of the rotor 31 can transmit power to the output shaft 10a of the engine 10 via a pulley or the like (not shown). When the rotary electric machine 30 is driven as a generator, the rotor 31 is rotated by the rotational power supplied from the output shaft 10a, and the rotary electric machine 30 generates electricity. The battery 20 is charged by the generated power of the rotary electric machine 30. On the other hand, when the rotary electric machine 30 is driven as an electric motor, the output shaft 10a rotates with the rotation of the rotor 31, and a rotational force is applied to the output shaft 10a. As a result, the engine 10 can be started and the running of the vehicle (driving force of the engine 10) can be assisted. The drive wheels of the vehicle are connected to the output shaft 10a via a transmission or the like.

The rotary electric machine 30 includes a stator 33. The stator 33 includes a stator winding. The stator windings include U, V, W phase windings 34U, 34V, 34W arranged 120 ° apart from each other in electrical angle.

The control system includes a three-phase inverter 40, a field energization circuit 41, and a capacitor 21. The inverter 40 includes a series connection body of U, V, W phase upper arm switches SUp, SVp, SWp and U, V, W phase lower arm switches SUn, SVn, SWn. U, V, W phase windings 34U, 34V, 34W at the connection points between the U, V, W phase upper arm switches SUP, SVp, SWp and the U, V, W phase lower arm switches SUn, SVn, SWn. The first end of is connected. The second ends of the U, V, W phase windings 34U, 34V, 34W are connected at a neutral point. That is, in the present embodiment, the U, V, W phase windings 34U, 34V, 34W are connected in a star shape. In this embodiment, IGBTs are used as the arm switches SUP to SWn. U, V, W phase upper arm diodes DUp, DVp, DWp are connected in antiparallel to the U, V, W phase upper arm switches SUP, SVp, SWp. U, V, W phase lower arm diodes DUn, DVn, DWn are connected in antiparallel to the U, V, W phase lower arm switches SUn, SVn, SWn.

The positive electrode terminal of the battery 20 is connected to the collector, which is the high potential side terminal of the U, V, W phase upper arm switches SUP, SVp, SWp, via the high potential side electric path Lp. The negative electrode terminal of the battery 20 is connected to the emitter which is the low potential side terminal of the U, V, W phase lower arm switches SUn, SVn, SWn via the low potential side electric path Ln. Each electric path Lp, Ln is a conductive member such as a bus bar. The high potential side terminal of the capacitor 21 is connected to the positive electrode terminal side of the battery 20 from the connection point of each of the upper arm switches SUP, SVp, and SWp in the high potential side electric path Lp with the collector. The low-potential side terminal of the capacitor 21 is connected to the negative electrode terminal side of the battery 20 from the connection point of each of the lower arm switches SUn, SVn, and SWn in the low-potential side electric path Ln with the emitter.

The field energization circuit 41 is a full bridge circuit, and includes a series connection of the first upper arm switch SH1 and the first lower arm switch SL1 and a series connection of the second upper arm switch SH2 and the second lower arm switch SL2. It has. The first end of the field winding 32 is connected to the connection point between the first upper arm switch SH1 and the first lower arm switch SL1 via a brush (not shown). The second end of the field winding 32 is connected to the connection point between the second upper arm switch SH2 and the second lower arm switch SL2 via a brush (not shown). In this embodiment, IGBTs are used as the arm switches SH1, SL1, SH2, SL2. Further, each diode DH1, DL1, DH2, DL2 is connected in antiparallel to each arm switch SH1, SL1, SH2, SL2.

The collector, which is the high potential side terminal of the first and second upper arm switches SH1 and SH2, is connected to the inverter 40 side of the high potential side electric path Lp from the connection point with the high potential side terminal of the capacitor 21. .. The inverter 40 side of the low potential side electric path Ln is connected to the emitter which is the low potential side terminal of the first and second lower arm switches SL1 and SL2 from the connection point with the low potential side terminal of the capacitor 21. ..

The control system includes a voltage detection unit 50, a phase current detection unit 51, a field current detection unit 52, and an angle detection unit 53. The voltage detection unit 50 detects the terminal voltage of the capacitor 21 as the power supply voltage VDC (battery voltage). The phase current detection unit 51 detects the phase current flowing through the U, V, W phase windings 34U, 34V, 34W. The field current detection unit 52 detects the field current flowing through the field winding 32. The angle detection unit 53 outputs an angle signal which is a signal corresponding to the rotation angle of the rotor 31. The output signals of the detection units 50 to 53 are input to the control device 60 provided in the vehicle. In the present embodiment, the rotary electric machine 30, the inverter 40, the field energization circuit 41, and the control device 60 are integrated to form a mechanical and electrical integrated drive device.

The control device 60 (modulation method switching device) includes a memory 68 corresponding to a storage unit. The memory 68 corresponds to a non-transitory computer readable medium, for example, a non-volatile memory. The control device 60 includes a first execution unit 61, a second execution unit 62, a third execution unit 63, a switching unit 64, and a determination unit 66. These will be described later.

A part or all of each function of the control device 60 may be configured in hardware by, for example, one or a plurality of integrated circuits. Further, each function of the control device 60 may be composed of, for example, software recorded on a non-transitional substantive recording medium and a computer that executes the software.

The control device 60 generates a drive signal for each switch constituting the inverter 40 and the field energization circuit 41.

First, the inverter 40 will be described. The control device 60 acquires the angle signal of the angle detection unit 53, and based on the acquired angle signal, generates a drive signal for turning on / off the switches SUP to SWn constituting the inverter 40. Specifically, when the rotary electric machine 30 is driven as an electric motor, the control device 60 converts the DC power output from the battery 20 into AC power and supplies it to the U, V, W phase windings 34U, 34V, 34W. , A drive signal for turning on / off each arm switch SUP to SWn is generated, and the generated drive signal is supplied to the gate of each arm switch SUP to SWn. On the other hand, when the rotary electric machine 30 is driven as a generator, the control device 60 converts the AC power output from the U, V, W phase windings 34U, 34V, 34W into DC power to convert the battery 20 and the load 22 into DC power. A drive signal for turning on / off each arm switch SUP to SWn is generated so as to supply to at least one of them.

Subsequently, the field energization circuit 41 will be described. The control device 60 turns on and off each switch constituting the field energization circuit 41 in order to excite the field winding 32. Specifically, the control device 60 turns each switch on and off so that the first state shown in FIG. 2A and the second state shown in FIG. 2B appear alternately. The first state is a state in which the first upper arm switch SH1 and the second lower arm switch SL2 are turned on, and the second upper arm switch SH2 and the first lower arm switch SL1 are turned off. The second state is a state in which the first upper arm switch SH1 and the second lower arm switch SL2 are turned off, and the second upper arm switch SH2 and the first lower arm switch SL1 are turned on.

The control device 60 calculates the electric angle θe of the rotary electric machine 30 and the rotation speed Nm of the rotor 31 based on the angle signal of the angle detection unit 53. The control device 60 is based on the phase current flowing through the U, V, W phase windings 34U, 34V, 34W detected by the phase current detection unit and the field current detected by the field current detection unit 52. Detects (estimates) the battery current flowing from the battery 20. The determination unit 66 determines that the abnormality is abnormal (overcurrent determination) when the detected battery current is larger than the predetermined current Ih and continues for a longer time than the predetermined time. The predetermined current Ih is the maximum current assumed as the battery current flowing when the engine 10 is started in a normal state. The predetermined time is a time during which it can be determined that the battery current is actually flowing, not the influence of noise or the like.

Subsequently, the torque control of the rotary electric machine 30 performed by the control device 60 will be described. 3 and 4 are block diagrams of torque control.

First, the torque control shown in FIG. 3 will be described. This torque control is performed when the rotation speed Nm of the rotary electric machine 30 is equal to or less than the first rotation speed Nm1, as shown by “3-phase modulation (Duty limitation)” in FIG. The method of setting the first rotation speed Nm1 will be described later.

The two-phase conversion unit 70 converts U, V, W phase currents IU, IV, IW in the three-phase fixed coordinate system of the rotary electric machine 30 based on the phase current and the electric angle θe detected by the phase current detection unit 51. It is converted into d, q-axis currents Idr, Iqr in the dq coordinate system, which is a two-phase rotation coordinate system.

The d-axis command setting unit 71 sets the torque of the rotary electric machine 30 as the command torque Trq * based on the command torque Trq * (required torque), the rotation speed Nm, and the power supply voltage VDC detected by the voltage detection unit 50. The d-axis command current Id * is set. Specifically, the d-axis command setting unit 71 is based on the map information in which the command torque Trq *, the rotation speed Nm, the power supply voltage VDC and the d-axis command current Id * are related, and the d-axis command current Id *. To set. This map information is stored in the memory 68.

The q-axis command setting unit 72 sets the q-axis command current Iq * for setting the torque of the rotary electric machine 30 to the command torque Trq * based on the command torque Trq *, the rotation speed Nm, and the power supply voltage VDC. Specifically, the q-axis command setting unit 72 uses the q-axis command current Iq * based on the map information in which the command torque Trq *, the rotation speed Nm, the power supply voltage VDC, and the q-axis command current Iq * are related. To set. This map information is stored in the memory 68.

The stator control unit 73 calculates the d-axis command voltage Vd * as an operation amount for feedback-controlling the d-axis current Idr to the d-axis command current Id *. Specifically, the stator control unit 73 calculates the d-axis current deviation ΔId as a value obtained by subtracting the d-axis current Idr from the d-axis command current Id *, and feedback-controls the calculated d-axis current deviation ΔId to 0. The d-axis command voltage Vd * is calculated as the operation amount of.

The stator control unit 73 calculates the q-axis command voltage Vq * as an operation amount for feedback-controlling the q-axis current Iqr to the q-axis command current Iq *. Specifically, the stator control unit 73 calculates the q-axis current deviation ΔIq as a value obtained by subtracting the q-axis current Iqr from the q-axis command current Iq *, and feedback-controls the calculated q-axis current deviation ΔIq to 0. The q-axis command voltage Vq * is calculated as the operation amount of.

In the present embodiment, the feedback control used by the stator control unit 73 is, for example, proportional integration control. The feedback control is not limited to the proportional integral control, and may be, for example, the proportional integral differential control.

The command voltage vector, which is the command value of the voltage vector in the dq coordinate system, is determined by the d-axis command voltage Vd * and the q-axis command voltage Vq *. Here, as shown in FIG. 6, the voltage vector Vtr applied to the stator winding has a d-axis component of the d-axis voltage Vd and a q-axis component of the q-axis voltage Vq. In the present embodiment, the voltage phase δ, which is the phase of the voltage vector Vtr, is defined with reference to the positive direction of the d-axis, and the counterclockwise direction is defined as the positive direction from this reference.

The three-phase conversion unit 74 sets the d, q-axis command voltages Vd *, Vq * based on the d, q-axis command voltages Vd *, Vq * and the electric angle θe to U, V, W in the three-phase fixed coordinate system. Converts to phase command voltage Vu *, Vv *, Vw *. In the present embodiment, the U, V, and W phase command voltages Vu *, Vv *, and Vw * have a sinusoidal waveform whose phase is shifted by 120 ° depending on the electrical angle.

The stator generation unit 75 turns on / off each switch SUP to SWn of the inverter 40 by sine wave PWM control based on the carrier signal (carrier wave), each phase command voltage Vu *, Vv *, Vw * and the power supply voltage VDC. Generate each drive signal of. Specifically, the sine wave PWM control generates each drive signal based on the magnitude comparison between the value obtained by dividing each phase command voltage Vu *, Vv *, Vw * by "VDC / 2" and the carrier signal. Is. The carrier signal is a triangular wave signal. Each drive signal is generated as a duty which is the ratio of the time for applying the power supply voltage VDC to the U, V, and W phases in a predetermined period. In "three-phase modulation (duty limitation)", the duty is limited to the first upper limit duty or less. The first upper limit duty is, for example, 80 [%].

In the sinusoidal PWM control, the value obtained by dividing the amplitude of each phase command voltage Vu *, Vv *, Vw * by "VDC / 2" is equal to or less than the amplitude of the carrier signal. In the present embodiment, the value obtained by dividing the amplitude of each phase command voltage Vu *, Vv *, Vw * by "VDC / 2" is defined as the modulation factor Mr. In the stator generation unit 75, the modulation factor Mr becomes 1 when the rotation speed Nm becomes the first rotation speed Nm1, and the modulation factor Mr becomes smaller than 1 when the rotation speed Nm is less than the first rotation speed Nm1. As the modulation factor, a value obtained by dividing the amplitude of the voltage command value by the amplitude of the carrier wave can also be adopted.

According to "three-phase modulation (duty limitation)", the actual voltage vector is controlled by the command voltage vector determined by the d and q-axis command voltages Vd * and Vq * while the duty is limited to the first upper limit duty or less. ..

The field command setting unit 80 sets the field command current If * based on the command torque Trq *, the rotation speed Nm, and the power supply voltage VDC. Specifically, the field command setting unit 80 uses the field command current If * based on the map information in which the command torque Trq *, the rotation speed Nm, the power supply voltage VDC, and the field command current If * are related. To set. This map information is stored in the memory 68.

The field current control unit 81 calculates the field command voltage Vf * as an operation amount for feedback-controlling the field current Ifr detected by the field current detection unit 52 to the field command current If *. Specifically, the field current control unit 81 calculates the field current deviation ΔIf as the value obtained by subtracting the field current Ifr from the field command current If *, and feedback-controls the calculated field current deviation ΔIf to 0. The field command voltage Vf * is calculated as the amount of operation for this operation. In the present embodiment, the feedback control used in the field current control unit 81 is, for example, proportional integration control. The feedback control is not limited to the proportional integral control, and may be, for example, the proportional integral differential control.

The field generation unit 82 sets the applied voltage of the field winding 32 to the field command voltage based on the magnitude comparison between the value obtained by dividing the field command voltage Vf * by the power supply voltage VDC and the carrier signal which is a triangular wave signal. Each drive signal of each switch SH1 to SL2 of the field energization circuit 41 for controlling to Vf * is generated.

Subsequently, the torque control shown in FIG. 4 will be described. This torque control is performed when the rotation speed Nm of the rotary electric machine 30 is equal to or higher than the third rotation speed Nm3 (> Nm2> Nm1), as shown by “overmodulation” in FIG. The control from "three-phase modulation (duty limitation)" to "overmodulation" is the control performed when the engine 10 is started. The method of setting the third rotation speed Nm3 will be described later.

The phase information setting unit 90 is a command voltage phase δ * which is a command value of a voltage phase δ for setting the torque of the rotary electric machine 30 into a command torque Trq * based on the command torque Trq *, the rotation speed Nm, and the power supply voltage VDC. To set. Specifically, the phase information setting unit 90 sets the command voltage phase δ * based on the command torque Trq *, the rotation speed Nm, and the map information in which the power supply voltage VDC and the command voltage phase δ * are related. .. This map information is stored in the memory 68.

The amplitude information setting unit 91 sets the command modulation factor Mr *, which is the command value of the modulation factor Mr, based on the command torque Trq *, the rotation speed Nm, and the power supply voltage VDC. Specifically, the amplitude information setting unit 91 sets the command modulation rate Mr * based on the command torque Trq *, the rotation speed Nm, and the map information in which the power supply voltage VDC and the command modulation rate Mr * are related. .. This map information is stored in the memory 68. The command modulation factor Mr * has a positive correlation with the voltage amplitude, which is the magnitude of the command voltage vector. The command modulation factor Mr * is used, for example, to determine the on-period Ton in square wave control (overmodulation control). The on period Ton is a period during which the switches SUP to SWn of the inverter 40 are turned on. The on-period Ton is set, for example, between 120 ° and 180 ° in electrical angle.

The pattern generation unit 92 transmits each drive signal of each switch SUP to SWn of the inverter 40 for driving the rotary electric machine 30 by the square wave control based on the command voltage phase δ *, the command modulation factor Mr *, and the electric angle θe. Generate. In the square wave control, in each phase, the state where the upper arm switch is turned on and the lower arm switch is turned off and the state where the upper arm switch is turned off and the lower arm switch is turned on are the electricity of the rotary electric machine 30. Appears once in one square cycle. Further, in the rectangular wave control, the switching of the upper arm switch to the off state is deviated by 120 ° from each other in the electric angle for each phase. In the square wave control, the torque of the rotary electric machine 30 is controlled by the command torque Trq * by controlling the voltage phase in a state where the amplitude of the fundamental wave component of the phase voltage of each phase winding is fixed.

In the memory 68, of the upper and lower arm switches, the first signal that turns on only the upper arm switch and the second signal that turns on only the lower arm switch are related to the electric angle θe for each of the three phases. The pulse pattern, which is map information, is stored. The pulse pattern is stored in the memory 68 in relation to the command modulation factor Mr * and the command voltage phase δ *. The pattern generation unit 92 selects a pulse pattern corresponding to the command modulation factor Mr * and the command voltage phase δ *, and generates a drive signal for each switch of the inverter 40 based on the selected pulse pattern. In the present embodiment, when the rotation speed Nm is the third rotation speed Nm3 or more, the modulation factor Mr becomes 1.27, which is the upper limit value thereof.

In FIG. 4, the field command setting unit 80, the field current control unit 81, and the field generation unit 82 have the same configuration as that shown in FIG.

According to the square wave control, the actual voltage vector is controlled by the command voltage vector determined by the command modulation factor Mr * and the command voltage phase δ *.

Subsequently, torque control when the rotation speed Nm is higher than the first rotation speed Nm1 and lower than the third rotation speed Nm3 will be described.

As shown in FIG. 5, when the rotation speed Nm of the rotary electric machine 30 is higher than the first rotation speed Nm1 and the second rotation speed Nm2 (> Nm1) or less, "two-phase modulation (duty limitation)" is performed. Will be The two-phase modulation method is well known as described in WO2010 / 119929, and the description thereof is omitted here by referring to the contents described in the same publication. The method of setting the second rotation speed Nm2 will be described later.

In the "two-phase modulation (duty limitation)" of the present embodiment, the duty is limited to the second upper limit duty (> first upper limit duty) or less while executing the two-phase modulation method. The second upper limit duty is, for example, 90 [%].

Further, when switching from "3-phase modulation (Duty limitation)" to "2-phase modulation (Duty limitation)", the duty is limited to the third upper limit duty or less, and the third upper limit duty is changed from the first upper limit duty to the first upper limit duty. 2 Gradually increase to the upper limit duty. For example, as shown in FIG. 7, when switching from "3-phase modulation (Duty limit)" to "2-phase modulation (Duty limit)" at time t11, the third upper limit is set at a constant speed from the first upper limit Duty with the passage of time. The duty is increased, and the third upper limit duty is set to the second upper limit duty at time t12.

As shown in FIG. 5, when the rotation speed Nm of the rotary electric machine 30 is higher than the second rotation speed Nm2 and is less than or equal to the third rotation speed Nm3 (> Nm2), "two-phase modulation" is performed. In "two-phase modulation", the duty is not limited, that is, the upper limit of the duty is 100 [%].

When switching from "two-phase modulation" to "two-phase modulation (duty limitation)", the duty is limited to the fourth upper limit duty or less, and the fourth upper limit duty is set from 100 [%] to the second upper limit duty. Gradually reduce to. For example, when switching from "two-phase modulation" to "two-phase modulation (duty limit)", the fourth upper limit Duty is reduced at a constant speed from 100 [%] with the passage of time, and the fourth upper limit Duty is set to the second upper limit. Let's call it Duty.

In each of the above-mentioned modulation methods, the applied voltage applied to each of the U, V, and W phases is limited to the upper limit voltage or less by the principle of each modulation method and the upper limit duty. The upper limit voltage of "3-phase modulation (Duty limitation)" is the lowest, and the upper limit voltage increases in the order of "2-phase modulation (Duty limitation)", "2-phase modulation", and "overmodulation", and "overmodulation" The upper limit voltage is the highest.

Here, the modulation method in which the applied voltage is limited to the first upper limit voltage or less is defined as the first modulation method, and the modulation method in which the applied voltage is limited to the second upper limit voltage or less higher than the first upper limit voltage is the second modulation method. The modulation method is defined as a modulation method in which the applied voltage is limited to a third upper limit voltage or lower, which is higher than the second upper limit voltage. At this time, in the control device 60, the portion that executes the first modulation method is the first execution unit 61 (see FIG. 1), the part that executes the second modulation method is the second execution unit 62, and the third modulation The part that executes the method is the third execution unit 63.

For example, if "three-phase modulation (Duty limitation)" is the first modulation method, any one of "two-phase modulation (Duty limitation)", "two-phase modulation", and "overmodulation" is the second modulation method. .. For example, if "two-phase modulation (Duty limitation)" is the second modulation method, either "two-phase modulation" or "overmodulation" is the third modulation method. Further, for example, if "two-phase modulation" is the first modulation method, "overmodulation" is the second modulation method.

Here, in the second modulation method, the applied voltage applied to each phase of the rotary electric machine 30 is limited to a second upper limit voltage higher than the first upper limit voltage. Therefore, the voltage applied to each phase by the second modulation method tends to be higher than the voltage applied to each phase by the first modulation method, and is transient when switching from the first modulation method to the second modulation method. Battery current may increase. In that case, the determination unit 66 may erroneously determine that the rotary electric machine 30, the inverter 40, and the field energization circuit 41 are not abnormal even though they are not abnormal. In order to suppress such an erroneous determination, the first to third rotation speeds Nm1 to Nm3 are set as follows in the present embodiment.

FIG. 8 is an equivalent circuit for explaining the phase current. Here, the applied voltage Vu applied to the U phase and the phase current Iu flowing through the U phase will be described as an example.

The U phase has a resistor R and an inductance L. In the U phase, an induced voltage ωφcosθ is generated as the rotor 31 of the rotary electric machine 30 rotates. ω is the angular velocity of the rotor 31, and φ is the magnetic flux penetrating the U-phase winding 34U. θ = ωt, where t is time. Therefore, it can be expressed by Vu = (L + R) Iu + ωφcosθ. Then, it can be expressed by Iu = (Vu−ωφcosθ) / (L + R). From this equation, it can be seen that the higher the angular velocity ω of the rotor 31, that is, the rotational speed Nm of the rotary electric machine 30, the lower the U-phase phase voltage (Vu−ωφcosθ) and the smaller the phase current Iu.

Therefore, when switching from the first modulation method to the second modulation method, the first to third rotation speeds Nm1 so that the U-phase phase voltage (Vu−ωφcosθ) in the second modulation method becomes lower than the predetermined voltage V1. ~ Nm3 is set. That is, in the switching unit 64 (see FIG. 1), the phase voltage obtained by subtracting the induced voltage ωφcosθ from the applied voltage Vu in the second modulation method is lower than the predetermined voltage V1 based on the rotation speed Nm of the rotary electric machine 30. Is a condition, the first modulation method is switched to the second modulation method. Then, the switching unit 64 has a phase voltage obtained by subtracting the induced voltage ωφcosθ from the applied voltage Vu in the third modulation method based on the rotation speed Nm of the rotary electric machine 30 from the predetermined voltage V2 (<V1) which is lower than the predetermined voltage V1. The second modulation method is switched to the third modulation method on condition that the voltage becomes lower. The rotation speed Nm of the rotary electric machine 30 corresponds to a parameter that correlates with the induced voltage induced in each phase with the rotation of the rotary electric machine 30.

FIG. 9 is a graph showing the relationship between the rotational speed Nm of the rotary electric machine 30 and the torque. Here, a case of switching from the first modulation method to the second modulation method at a switching rotation speed of Nm12 will be described as an example. The solid line shows the command torque Trq *, the alternate long and short dash line shows the maximum torque Trq1 in the first modulation method, and the broken line shows the maximum torque Trq2 in the second modulation method. The maximum torque Trq1 is the maximum value of the torque that can be generated by the rotary electric machine 30 in the first modulation method. The maximum torque Trq2 is the maximum value of the torque that can be generated by the rotary electric machine 30 in the second modulation method.

When the rotation speed Nm exceeds the switching rotation speed Nm12, the maximum torque Trq1 in the first modulation method becomes smaller than the command torque Trq *, and the command torque Trq * cannot be output in the first modulation method. Therefore, the switching unit 64 changes from the first modulation method to the second modulation method when the rotation speed Nm becomes the switching rotation speed Nm12, that is, before the maximum torque Trq1 in the first modulation method becomes smaller than the command torque Trq *. Switch to.

The maximum torque Trq2 in the second modulation method is larger than the command torque Trq * even if the rotation speed Nm exceeds the switching rotation speed Nm12. Therefore, in the second modulation method, the command torque Trq * can be output even if the rotation speed Nm exceeds the switching rotation speed Nm12.

FIG. 10 is a graph showing the relationship between the rotation speed Nm, the phase voltage (Vu−ωφcosθ), the induced voltage ωφcosθ, and the applied voltage Vu. Here, a case similar to that of FIG. 9 will be described as an example. In FIG. 10 (c), the solid line shows the U-phase command voltage Vu *, the alternate long and short dash line shows the maximum applied voltage Vu1 in the first modulation method, and the broken line shows the maximum applied Vu2 in the second modulation method. There is. The maximum applied voltage Vu1 is the maximum value of the voltage that can be applied to the U phase in the first modulation method. The maximum applied voltage Vu2 is the maximum value of the voltage that can be applied to the U phase by the second modulation method.

When the rotation speed Nm exceeds the switching rotation speed Nm12, the maximum applied voltage Vu1 in the first modulation method becomes lower than the U-phase command voltage Vu *, and the U-phase command voltage Vu * can be output in the first modulation method. It disappears. Therefore, the switching unit 64 starts from the first modulation method when the rotation speed Nm becomes the switching rotation speed Nm12, that is, before the maximum applied voltage Vu1 in the first modulation method becomes lower than the U-phase command voltage Vu *. Switch to the 2-modulation method. At this time, as shown in FIG. 10A, the phase voltage Vc of the U phase at the switching rotation speed Nm12 is lower than the predetermined voltage V1. That is, the phase voltage of the U phase in the second modulation method is made lower than the predetermined voltage V1 by switching from the first modulation method to the second modulation method on condition that the rotation speed Nm becomes the switching rotation speed Nm12. be able to. Therefore, it is possible to suppress an increase in the phase current Iu when switching from the first modulation method to the second modulation method.

The maximum applied voltage Vu2 in the second modulation method is higher than the U-phase command voltage Vu * even if the rotation speed Nm exceeds the switching rotation speed Nm12. Therefore, in the second modulation method, the U-phase command voltage Vu * can be output even if the rotation speed Nm exceeds the switching rotation speed Nm12.

The induced voltage ωφcosθ induced in the U phase with the rotation of the rotary electric machine 30 increases as the rotation speed Nm of the rotary electric machine 30 increases. Therefore, if hysteresis is provided in the rotation speed Nm12 for switching from the first modulation method to the second modulation method and the rotation speed Nm21 for switching from the second modulation method to the first modulation method, the second modulation method is changed to the second modulation method. The switching to the 1-modulation method may be delayed and the applied voltage Vu (see Vu2 in FIG. 10C) may increase. In that case, the battery current may increase in the second modulation method. Therefore, in the present embodiment, the rotation speed Nm12 for switching from the first modulation method to the second modulation method and the rotation speed Nm21 for switching from the second modulation method to the first modulation method are the same. Similarly, the rotation speed Nm23 for switching from the second modulation method to the third modulation method and the rotation speed Nm32 for switching from the third modulation method to the second modulation method are the same.

Further, as shown in FIG. 5, when the rotation speed Nm of the rotary electric machine 30 is higher than the predetermined rotation speed Nm4 (> Nm3), for example, when the rotary electric machine 30 assists the driving force of the engine 10, the rotary electric machine 30 is used. It is desirable to suppress fluctuations in the generated torque. The modulation method switching based on the modulation factor Mr can suppress the fluctuation of the torque generated by the rotary electric machine 30 as compared with the modulation method switching based on the rotation speed Nm of the rotary electric machine 30 described above.

Therefore, in the present embodiment, when the driving force of the engine 10 is assisted by the rotary electric machine 30, that is, when the rotation speed Nm of the rotary electric machine 30 is higher than the predetermined rotation speed Nm4, the modulation method is based on the command modulation rate Mr *. To switch. Specifically, when the command modulation factor Mr * is the first modulation factor Mr1 or less, "for three-phase modulation assist (with neutral point shift)" is performed. When the command modulation factor Mr * is larger than the first modulation factor Mr1 and is equal to or less than the second modulation factor Mr2 (> Mr1), "for two-phase modulation assist" is performed. When the command modulation factor Mr * is larger than the second modulation factor Mr2, "for overmodulation assist" is performed. The upper limit voltage of "for 3-phase modulation assist (with neutral point shift)" is the lowest, and the upper limit voltage increases in order of "for 2-phase modulation assist" and "for overmodulation assist", and "for overmodulation assist". The upper limit voltage of is the highest.

FIG. 11 is a time chart showing the switching mode of the modulation method.

With the passage of time, the modulation method is switched from "three-phase modulation (Duty limitation)" to "two-phase modulation (Duty limitation)", "two-phase modulation", and "overmodulation" in this order. Specifically, the rotation speed Nm is switched to "two-phase modulation (Duty limitation)" at the first rotation speed Nm1, is switched to "two-phase modulation" at the second rotation speed Nm2, and is switched to "two-phase modulation" at the third rotation speed Nm3. It has been switched to "overmodulation". Further, as the rotation speed Nm increases, the upper limit value of the duty is gradually increased. The battery current is smaller than the predetermined current Ih, and the determination unit 66 is prevented from erroneously determining the abnormality.

The present embodiment described in detail above has the following advantages.

In the second modulation method executed by the second execution unit 62, the switching unit 64 is based on a parameter (rotation speed Nm) that correlates with the induced voltage ωφcosθ induced in each phase with the rotation of the rotary electric machine 30. The first modulation method is switched to the second modulation method on condition that the phase voltage obtained by subtracting the induced voltage ωφcosθ from the applied voltage Vu (Vv, Vw) becomes lower than the predetermined voltage V1. That is, the phase voltage obtained by subtracting the induced voltage ωφcosθ from the applied voltage Vu applied to each phase 34U (34V, 34W) contributes to the increase in current. Therefore, it is possible to suppress the transient increase (fluctuation) of the battery current by switching from the first modulation method to the second modulation method on condition that the phase voltage becomes lower than the predetermined voltage V1. ..

The induced voltage ωφcosθ induced in each phase with the rotation of the rotary electric machine 30 changes according to the rotation speed Nm of the rotary electric machine 30 and the magnetic flux density of the magnetic field. Generally, the change speed of the rotation speed Nm of the rotary electric machine 30 is higher than the change speed of the magnetic flux density due to the field current flowing in the field winding 32. In this regard, the above parameters include the rotation speed Nm of the rotary electric machine 30. According to such a configuration, the first modulation method can be switched to the second modulation method based on the rotation speed Nm of the rotary electric machine 30 whose change speed is generally higher than the magnetic flux density. Therefore, even if the induced voltage ωφcosθ changes with the change of the rotation speed Nm of the rotary electric machine 30, it is accurately determined that the phase voltage becomes lower than the predetermined voltage V1, and the first modulation method to the second modulation method are performed. You can switch to the method.

When the induced voltage ωφcosθ induced in each phase increases with the rotation of the rotary electric machine 30, the maximum value of the torque that can be generated by the rotary electric machine 30 decreases. Therefore, it is desirable to switch to a modulation method capable of generating a larger torque before the rotary electric machine 30 cannot generate the command torque Trq *. In this respect, the switching unit 64 is further conditioned on the condition that the maximum value of the torque that can be generated by the rotary electric machine 30 in the first modulation method executed by the first execution unit 61 is before the command torque Trq * becomes smaller. , Switch from the first modulation method to the second modulation method. According to such a configuration, not only the transient increase in battery current is suppressed, but also the modulation method is switched to a modulation method capable of generating a larger torque before the rotary electric machine 30 cannot generate the command torque Trq *. be able to.

The switching unit 64 switches between the first modulation method and the second modulation method based on the rotation speed Nm of the rotary electric machine 30, and switches from the first modulation method to the second modulation method from the rotation speed Nm12 and the second modulation method. The rotation speed Nm21 for switching to the first modulation method is the same. According to such a configuration, it is possible to suppress the delay in switching from the second modulation method to the first modulation method, and it is possible to suppress an increase in the battery current in the second modulation method.

-The second execution unit 62 limits the duty to the third upper limit Duty or less when the first modulation method is switched to the second modulation method, and sets the third upper limit Duty from the first upper limit Duty to the second upper limit Duty. Gradually increase. Therefore, when the first modulation method is switched to the second modulation method, it is possible to suppress a sudden increase in the applied voltage Vu, and it is possible to suppress a transient increase in the battery current.

The switching unit 64 has a second predetermined voltage V2 in which the phase voltage obtained by subtracting the induced voltage ωφcosθ from the applied voltage Vu applied to each phase by the third execution unit 63 based on the above parameters is lower than the first predetermined voltage V1. The second modulation method is switched to the third modulation method on condition that the voltage becomes lower than the above. Therefore, it is possible to suppress the transient increase (fluctuation) of the battery current. Further, since the modulation method switching device includes the third execution unit 63 in addition to the first execution unit 61 and the second execution unit 62, the applied voltage Vu can be gradually increased. As a result, it is possible to further suppress the transient increase in battery current.

When the rotation speed Nm of the rotary electric machine 30 is lower than the predetermined rotation speed Nm4, the first modulation method is switched to the second modulation method based on the parameter correlating with the induced voltage ωφcosθ. Therefore, it is possible to suppress a rapid increase in battery current. On the other hand, when the rotation speed Nm of the rotary electric machine 30 is higher than the predetermined rotation speed Nm4, the modulation method is switched based on the modulation rate (command modulation rate Mr *) of the command value of the applied voltage Vu. Therefore, it is possible to give priority to suppressing the fluctuation of the torque generated by the rotary electric machine 30 rather than suppressing the fluctuation of the battery current.

The determination unit 66 determines that an abnormality occurs when the estimated battery current is larger than the predetermined current Ih and continues for a longer time than the predetermined time. In such a configuration, it is possible to suppress a transient increase in the battery current, so that it is possible to prevent the determination unit 66 from erroneously determining an abnormality when switching the modulation method.

<Second Embodiment>
Hereinafter, the second embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, as shown in FIG. 12, the rotary electric machine includes two stator winding groups (systems). Therefore, the control system includes a first inverter 40A and a second inverter 40B. In FIG. 12, the same components as those shown in FIG. 1 above are designated by the same reference numerals for convenience. Further, in FIG. 12, the field energization circuit 41, the control device 60, and the like are not shown.

The stator 33 of the rotary electric machine includes a first stator winding group and a second stator winding group. The first stator winding group (first system) includes first U, V, W phase windings 34UA, 34VA, 34WA that are offset by 120 ° from each other in terms of electrical angle. The second stator winding group (second system) includes second U, V, W phase windings 34UB, 34VB, 34WB that are offset by 120 ° from each other in terms of electrical angle. In the present embodiment, as shown in FIG. 13, the spatial phase difference Δθ, which is the angle formed by the first stator winding group and the second stator winding group, is set to 30 ° in terms of electrical angle.

The first inverter 40A includes a series connection body of the first U, V, W phase upper arm switches SUp1, SVp1, SWp1 and the first U, V, W phase lower arm switches SUn1, SVn1, SWn1. The first U, V, W phase upper arm switches DUp1, DVp1, DWp1 are connected in antiparallel to the first U, V, W phase upper arm switches SUp1, SVp1, SWp1. The first U, V, W phase lower arm diodes DUn1, DVn1, DWn1 are connected in antiparallel to the first U, V, W phase lower arm switches SUn1, SVn1, SWn1.

The second inverter 40B includes a series connection body of the second U, V, W phase upper arm switches SUp2, SVp2, SWp2 and the second U, V, W phase lower arm switches SUn2, SVn2, SWn2. The second U, V, W phase upper arm switches SUp2, SVp2, SWp2 are connected in antiparallel to the second U, V, W phase upper arm diodes DUp2, DVp2, and DWp2. The second U, V, W phase lower arm diodes DUn2, DVn2, DWn2 are connected in antiparallel to the second U, V, W phase lower arm switches SUn2, SVn2, SWn2.

The positive electrode terminals of the battery 20 are connected to the collectors of the upper arm switches SUp1 to SWp2 via the high potential side electric path Lp. The negative electrode terminal of the battery 20 is connected to the emitters of the lower arm switches SUn1 to SWn2 via the low potential side electric path Ln. The high potential side terminal of the capacitor 21 is connected to the positive electrode terminal side of the battery 20 from the connection point of each of the upper arm switches SUp1 to SWp2 in the high potential side electric path Lp with the collector. The low-potential side terminal of the capacitor 21 is connected to the negative electrode terminal side of the battery 20 from the connection point of each of the lower arm switches Sun1 to SWn2 in the low-potential side electric path Ln.

When the rotary electric machine includes a plurality of stator winding groups, if the modulation method is switched at the same time in the plurality of stator winding groups, the transient fluctuation of the battery current may be amplified.

Therefore, in the present embodiment, the timing of switching the modulation method in the plurality of stator winding groups is different from each other. For example, when the rotation speed Nm becomes the switching rotation speed Nm12, the first stator winding group switches from the first modulation method to the second modulation method, and then when a predetermined delay period elapses, the second stator winding group Switch from the first modulation method to the second modulation method. According to such a configuration, even when the rotary electric machine includes a plurality of stator winding groups, it is possible to suppress the amplification of transient battery current fluctuations.

<Other Embodiments>
Each of the above embodiments can be modified and implemented as follows. The same parts as those in each of the above embodiments are designated by the same reference numerals, and the description thereof will be omitted.

The drive state of the rotary electric machine 30 associated with each command value stored in the memory 68 is not limited to all of the command torque Trq *, the rotation speed Nm, and the power supply voltage VDC. As the driving state, at least one of the command torque Trq *, the rotation speed Nm, and the power supply voltage VDC may be used.

-The configuration is not limited to the configuration in which each command value is stored in the memory 68. For example, each command value may be calculated for each control cycle based on the acquired command torque Trq *, rotation speed Nm, and power supply voltage VDC.

-The control performed when the modulation factor is larger than 1 is not limited to the rectangular wave control shown in FIG. For example, the 120 ° energization control shown in FIG. 14 may be used.

Further, as the control performed when the modulation factor is larger than 1, in each phase, the upper arm switch is turned on and the lower arm switch is turned off, and the upper arm switch is turned off and the lower arm switch is turned off. The state in which is turned on is not limited to the one that appears once in one cycle of the electric angle of the rotary electric machine. For example, for the purpose of reducing the harmonic component contained in each phase voltage, the upper arm switch is turned on while setting the amplitude of the fundamental wave component contained in each phase voltage to the amplitude corresponding to the modulation factor of the square wave control. The state in which the lower arm switch is turned off and the state in which the upper arm switch is turned off and the lower arm switch is turned on may appear a plurality of times in one electric angle cycle.

The switching unit 64 switches between the first modulation method and the second modulation method based on the rotation speed Nm of the rotary electric machine 30, and switches from the first modulation method to the second modulation method from the rotation speed Nm12 and the second modulation method. It is also possible to adopt a configuration in which the rotation speed Nm21 for switching to the first modulation method is not the same.

The switching unit 64 performs the first modulation after the maximum value of the torque that can be generated by the rotary electric machine 30 in the first modulation method executed by the first execution unit 61 becomes smaller than the command torque Trq * (required torque). It is also possible to switch from the method to the second modulation method. That is, the switching unit 64 first modulates that the maximum value of the torque that can be generated by the rotary electric machine 30 in the first modulation method executed by the first execution unit 61 is before the command torque Trq * becomes smaller. It can also be deleted from the condition for switching from the method to the second modulation method.

The control device 60 may only switch the modulation method and may not limit the upper limit value of the duty. Even in this case, in each modulation method, the applied voltage applied to each of the U, V, and W phases is limited to the upper limit voltage or less of each by the principle of each modulation method.

The control device 60 is not limited to the one including the first to third execution units that execute the first to third modulation methods, and the applied voltage applied to each phase of the rotary electric machine 30 is larger than the third upper limit voltage. It may include a fourth execution unit that executes a fourth modulation method limited to a high fourth upper limit voltage or less. Then, in the switching unit 64, the phase voltage obtained by subtracting the induced voltage from the applied voltage applied to each phase by the fourth executing unit is lower than the second predetermined voltage V2 based on the rotation speed Nm of the rotary electric machine 30. The third modulation method may be switched to the fourth modulation method on condition that the voltage becomes lower than the predetermined voltage V3. Further, the control device 60 may include only the first and second execution units that execute the first and second modulation methods.

-The magnetic flux density of the magnetic field may be included as a parameter that correlates with the induced voltage induced in each phase with the rotation of the rotary electric machine 30. The magnetic flux density can be calculated based on the field current flowing through the field winding 32 detected by the field current detection unit 52.

The switch used in the inverter 40 and the field energization circuit 41 may be, for example, an N-channel MOSFET.

-The rotating electric machine is not limited to the one connected in a star shape, and may be connected in a delta shape, for example.

The rotary electric machine 30 (double-phase rotary electric machine) is not limited to a three-phase rotary electric machine, and may be a four-phase or higher-phase rotary electric machine or the like. The rotary electric machine 30 is not limited to the field type rotary electric machine, and may be a permanent magnet type rotary electric machine. Further, the rotary electric machine 30 may not have the function of a generator but may have only the function of an electric motor. When the rotary electric machine 30 is a permanent magnet type rotary electric machine, the temperature of the permanent magnet may be included as a parameter that correlates with the induced voltage induced in each phase with the rotation of the rotary electric machine 30.

20 ... Battery, 30 ... Rotating electric machine, 60 ... Control device, 61 ... First execution unit, 62 ... Second execution unit, 64 ... Switching unit.

Claims (9)

A modulation method switching device (60) for switching a modulation method when controlling a double-phase rotary electric machine (30) driven by a battery voltage applied from a battery (20).
A first modulation method in which the applied voltage applied to each phase (34U, 34V, 34W, 34UA, 34VA, 34WA, 34UB, 34VB, 34WB) of the double-phase rotary electric machine is limited to the first upper limit voltage or less. The first execution unit (61) to be executed and
A second execution unit (62) that executes a second modulation method in which the applied voltage applied to each phase of the double-phase rotary electric machine is limited to a second upper limit voltage higher than the first upper limit voltage and lower.
In the second modulation method executed by the second execution unit, the induced voltage is derived from the applied voltage based on the parameters correlated with the induced voltage induced in each phase with the rotation of the double-phase rotating electric machine. A switching unit (64) for switching from the first modulation method to the second modulation method on condition that the subtracted phase voltage becomes lower than a predetermined voltage.
Modulation method switching device including. The modulation method switching device according to claim 1, wherein the parameter includes the rotation speed of the dual-phase rotary electric machine. The switching unit is further provided on the condition that the maximum value of the torque that can be generated by the dual-phase rotary electric machine in the first modulation method executed by the first execution unit is before the required torque becomes smaller than the required torque. The modulation method switching device according to claim 1 or 2, which switches from the first modulation method to the second modulation method. The switching unit switches between the first modulation method and the second modulation method based on the rotation speed of the double-phase rotary electric machine, and switches from the first modulation method to the second modulation method, and the rotation speed and the above. The modulation method switching device according to any one of claims 1 to 3, wherein the rotation speed for switching from the second modulation method to the first modulation method is the same. The first execution unit controls the duty, which is the ratio of the time during which the battery voltage is applied to each phase in the predetermined period in the first modulation method, and limits the duty to the first upper limit duty or less.
The second execution unit controls the duty in the second modulation method, limits the duty to a second upper limit duty larger than the first upper limit duty, and limits the duty to a second upper limit duty or less.
When the first modulation method is switched to the second modulation method, the second execution unit limits the duty to the third upper limit duty or less, and limits the third upper limit duty from the first upper limit duty to the first upper limit duty. The modulation method switching device according to any one of claims 1 to 4, wherein the modulation method is gradually increased to the second upper limit duty. A third execution unit (63) for executing a third modulation method in which the applied voltage applied to each phase of the double-phase rotary electric machine is limited to a third upper limit voltage higher than the second upper limit voltage is provided. ,
The predetermined voltage is the first predetermined voltage.
In the switching unit, the phase voltage obtained by subtracting the induced voltage from the applied voltage applied to each phase by the third executing unit based on the parameter is lower than the second predetermined voltage, which is lower than the first predetermined voltage. The modulation method switching device according to any one of claims 1 to 5, which switches from the second modulation method to the third modulation method on condition that the voltage becomes lower. When the rotation speed of the double-phase rotary electric machine is lower than the predetermined rotation speed, the switching unit subtracts the induced voltage from the applied voltage applied to each phase by the second execution unit based on the parameters. The application is performed when the first modulation method is switched to the second modulation method on condition that the phase voltage is lower than the predetermined voltage and the rotation speed of the double-phase rotating electric machine is higher than the predetermined rotation speed. The modulation method switching device according to any one of claims 1 to 6, wherein the modulation method is switched based on the modulation rate of the command value of the voltage. A detector that detects the battery current flowing from the battery,
Any of claims 1 to 7, further comprising a determination unit (66) for determining an abnormality when the state in which the battery current detected by the detection unit is larger than the predetermined current continues for a longer than a predetermined time. The modulation method switching device according to item 1. The multi-phase rotary electric machine includes a plurality of systems having each of the phases.
The modulation method switching device according to any one of claims 1 to 8, wherein the timing for switching the modulation method in the plurality of systems is different from each other.

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