JP7031460B2 - Rotating machine control device - Google Patents

Description

The present invention relates to a control device for a rotary electric machine.

Conventionally, a control device has been proposed in which the electromagnetic noise of a rotary electric machine is reduced by controlling the drive of a PWM inverter (for example, Patent Document 1). In the control device of Patent Document 1, the on / off pattern of the PWM pulse is changed by randomly changing the carrier frequency, the component of the switching frequency is diffused, the harmonic component is suppressed, and the electromagnetic noise of the rotating electric machine is reduced. is doing.

Japanese Unexamined Patent Publication No. 2017-85847

By the way, as a rotary electric machine used in a vehicle, a field winding type synchronous motor may be adopted. In the field winding type synchronous motor, the input voltage to the field winding may be duty-controlled when controlling the rotation speed or the like.

However, when the duty of the input voltage to the field winding is controlled, the input voltage is turned on and off at a predetermined switching frequency. Therefore, depending on the switching frequency, the harmonic component may become large and electromagnetic noise may be generated. Further, the armature winding to which the PWM pulse is input and the field winding may resonate magnetically, and the harmonic resonance may increase the harmonic component and increase the electromagnetic noise.

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a control device for suppressing electromagnetic noise that may occur when driving a rotary electric machine.

In order to solve the above problems, the first means is a control device for a rotary electric machine applied to a control system including a rotary electric machine having a field winding and an armature winding and an inverter for driving the rotary electric machine. In the armature control unit that controls the armature current of the armature winding by PWM control that generates a PWM pulse based on the command voltage and the carrier for the rotating electric machine and outputs the PWM pulse to the inverter. A field control unit that controls the field current flowing in the field winding by duty control that changes the on / off time ratio of the input voltage to the field winding, and switching in the carrier frequency of the carrier and the duty control. A frequency spreading unit for spreading at least one of the frequencies is provided.

As a result, it is possible to suppress magnetic resonance between the armature winding and the field winding, and suppress electromagnetic noise.

The figure which shows the control system. The figure which shows the pattern of a PWM pulse. The figure which shows the pattern of a PWM pulse. The figure which shows the pattern of a PWM pulse. The figure which shows the pattern of a PWM pulse. The figure which shows the on / off pattern of a switch. The figure which shows the on / off pattern of a switch. A flowchart showing the diffusion process. The figure which shows the pattern of the PWM pulse of the 2nd Embodiment. The figure which shows the pattern of the PWM pulse of the 2nd Embodiment. The figure which shows the control system of 2nd Embodiment. The flowchart which shows the diffusion process of 3rd Embodiment.

(First Embodiment)
Hereinafter, the first embodiment will be described with reference to the drawings. In each of the following embodiments, the parts that are the same or equal to each other are designated by the same reference numerals in the drawings. The control system 100 according to the present embodiment will be described. The control device of the rotary electric machine is applied to this control system 100. As shown in FIG. 1, the control system 100 includes a control device 10, a field control circuit 20, and an inverter 30 to control the drive of the motor 40.

The motor 40 is an AC-driven rotary electric machine, and in the present embodiment, a winding field type synchronous machine is used. The motor 40 is connected to a battery 50 that supplies electric power as a DC power source via a control system 100. The battery 50 is, for example, a lead storage battery having a rated voltage of 12 V. Further, in the present embodiment, as the motor 40, an ISG (Integrated Starter Generator), which is a generator to which the function of an electric motor is added, is used.

The motor 40 includes a rotor 41 as a rotor. The rotor 41 includes a field winding 42. The rotating shaft of the rotor 41 can transmit power to the crank shaft of the engine 60 via a pulley or the like (not shown). When the motor 40 is driven as a generator, the rotor 41 is rotated by the rotational power supplied from the crank shaft, and the motor 40 generates electricity. The battery 50 is charged by the generated power of the motor 40. On the other hand, when the motor 40 is driven as an electric motor, the crank shaft rotates with the rotation of the rotor 41, and a rotational force is applied to the crank shaft. This makes it possible to assist the traveling of the vehicle, for example. The drive wheels of the vehicle are connected to the crank shaft via a transmission or the like. Further, the motor 40 includes a stator 44 as an armature. The stator 44 includes an armature winding 45. The armature winding 45 includes U, V, W phase windings 45U, 45V, 45W arranged so as to be offset from each other by 120 ° in electrical angle.

The inverter 30 is a three-phase inverter including a series of switches Sw31 and Sw32, a series of switches Sw33 and Sw34, and a series of switches Sw35 and Sw36. The input terminal of the inverter 30 is connected to the output terminal of the battery 50, and the connection points of the series of the inverter 30 are connected to the U, V, W phase windings 45U, 45V, 45W of the motor 40, respectively. There is. Further, body diodes D31 to D36 are connected in parallel to the switches Sw31 to Sw36, respectively. In the present embodiment, the switches Sw31 to Sw36 employ IGBTs, but other switching elements such as MOSFETs may be adopted.

In the inverter 30, the switches Sw31 to Sw36 are controlled by PWM pulses, respectively, and three-phase alternating current is passed through the U, V, W phase windings 45U, 45V, 45W of the motor 40 based on the input system voltage. Drives the motor 40. Specifically, the operation signals g31 to g36 transmitted from the control device 10 control the drive of the switches Sw31 to Sw36, so that the U, V, W phase windings 45U, 45V, 45W of the motor 40 are connected to the motor 40. The command voltage is applied to. The PWM pulse is a pulse generated by the control device 10 according to the command voltage to the motor 40, and is a pulse representing the on / off of the switches Sw31 to 36. The operation signals g31 to g36 are gate drive signals generated by the control device 10 so that the on / off pattern of Sw31 to Sw36 becomes a PWM pulse pattern.

The field control circuit 20 is a circuit composed of a switch 21, one end of which is connected to the output terminal (positive electrode side) of the battery 50, and the other end of which is connected to one end of the field winding 42. The other end of the field winding 42 is connected to the output terminal (negative electrode side) of the battery 50. As a result, the field current flows through the field winding 42 by turning the switch 21 on and off. The switch 21 employs, for example, another switching element such as a MOSFET. The on / off drive of this switch 21 is controlled by the operation signal g21 transmitted from the control device 10.

The control device 10 is mainly composed of a microcomputer equipped with a CPU, ROM, RAM, I / O, etc., and the CPU realizes various functions by executing a program stored in the ROM. For example, the control device 10 has a function as an armature control unit 11 and a function as a field control unit 12. The various functions may be realized by electronic circuits that are hardware, or at least a part of them may be realized by software, that is, processing executed on a computer.

As shown in FIGS. 2 to 5, the armature control unit 11 controls the inverter 30 based on the comparison between the command voltage (in this embodiment, the voltage waveform of a sine wave) and the carrier wave (carrier). To generate. Specifically, a PWM pulse for controlling the inverter 30 is generated based on the comparison between the command voltage and the carrier wave. Then, the armature control unit 11 generates operation signals g31 to g36 based on the generated PWM pulse, and transmits the generated operation signals g31 to g36 to the gate terminals of the switches Sw31 to Sw36, respectively. The command voltage for the motor 40 is calculated based on the command value for the control amount of the motor 40 transmitted from the upper control device (for example, the engine ECU). The controlled amount of the motor 40 is, for example, torque or rotation speed.

As shown in FIGS. 6 and 7, the field control unit 12 executes duty control for changing the on / off time ratio of the input voltage (power supply voltage) to the field winding 42, and the field flows through the field winding 42. Control the current. Specifically, the field control unit 12 specifies the timing of applying the power supply voltage to the field winding 42 and the timing of stopping the application based on the on / off time ratio, that is, the duty ratio, and the switch 21 is turned on / off based on the timing. The operation signal g21 for controlling the above is transmitted.

In the present embodiment, the time (on time) for applying the power supply voltage (battery voltage) is fixed, and the on / off time ratio of the input voltage in the duty control is adjusted by adjusting the time (off time) for not applying the power supply voltage. is doing. That is, the duty ratio is increased by shortening the off time, while the duty ratio is decreased by lengthening the off time. The on / off time ratio, that is, the duty ratio is calculated based on the command value for the control amount of the motor 40 transmitted from the upper control device.

By the way, when the exciting current to the field winding 42 is controlled by duty control, when the motor control amount is constant, the input to the field winding 42 is performed at a predetermined switching frequency (that is, in a predetermined cycle). The voltage will be turned on and off. Therefore, depending on the switching frequency, the harmonic component (high frequency component) may become large and electromagnetic noise may be generated. Similarly, when the armature current to the armature winding 45 is controlled by PWM control, when a PWM pulse is generated at a predetermined carrier frequency, the harmonic component (high frequency component) becomes large and electromagnetic noise is generated. there's a possibility that. Further, depending on the switching frequency and the carrier frequency, magnetic resonance may occur at the natural resonance point of the motor 40 (or due to the mutual inductance between the armature winding 45 and the field winding 42). When magnetic resonance occurs, the high frequency component becomes large, and electromagnetic noise may become large.

Therefore, the control device 10 of the present embodiment is provided with a function as a frequency spreading unit 13 for diffusing at least one of the carrier frequency of the carrier wave and the switching frequency in the duty control. Hereinafter, the diffusion process executed by the control device 10 as the frequency diffusion unit 13 will be described with reference to FIG. The diffusion process is executed at predetermined intervals while the motor 40 is being driven, that is, when a current is passed through the motor 40.

The control device 10 determines whether or not the PWM control executed by the armature control unit 11 is a sinusoidal PWM control (step S101). The sinusoidal PWM control is a PWM control executed when the modulation factor is within the first modulation factor range. The modulation factor is a value obtained by dividing the command voltage (amplitude in the case of a waveform) for the motor 40 by the system voltage (or the amplitude of the carrier wave) input to the inverter 30. The first modulation factor range is, for example, a modulation factor in the range of 75% to 100%.

If the determination result in step S101 is affirmative, the control device 10 diffuses the frequency of the carrier wave (hereinafter, carrier frequency) used when generating the PWM pulse (step S102). Specifically, the fundamental frequency is diffused (varies) irregularly and discontinuously within a certain diffusion range with reference to the fundamental frequency of the carrier frequency. The diffusion range is, for example, a range in which the fundamental frequency is increased or decreased by several percent. Further, in the case of diffusion (variation), it is desirable that the average value of the carrier frequency after diffusion is substantially the same as the fundamental frequency of the carrier frequency before diffusion. Then, the diffusion process is terminated.

By diffusing the carrier frequency in this way, as shown in FIGS. 2 and 3, the on / off pattern of the PWM pulse can be changed, and the harmonic component (high frequency component) is suppressed. Note that FIG. 2 shows an on / off pattern of the PWM pulse before diffusion, and FIG. 3 shows an on / off pattern of the PWM pulse after diffusion. In FIGS. 2 and 3, the conditions other than the carrier frequency are the same.

On the other hand, if the determination result in step S101 is negative, the control device 10 determines whether or not the PWM control executed by the armature control unit 11 is overmodulation PWM control (step S103). The overmodulation PWM control is a PWM control executed when the modulation factor is within the second modulation factor range. The second modulation factor range is a range in which the modulation factor is higher than the first modulation factor range, and is, for example, a range of 101% to 125%. If the determination result in step S103 is negative, the diffusion process is terminated.

On the other hand, when the determination result in step S103 is affirmative, the control device 10 spreads the carrier frequency and spreads the switching frequency in the detail control as described above (step S104). In the present embodiment, the switching frequency in the detail control is diffused by varying the off time of the switch 21 within a predetermined time range. Specifically, the off time is irregularly and discontinuous within a certain time range based on the off time before diffusion. The time range is, for example, a range in which the off time is increased or decreased by several percent. Further, in the case of diffusion (variation), it is desirable that the average value of the off time after diffusion is almost the same as the off time before diffusion. That is, it is desirable that the average value of the frequencies after diffusion is almost the same as the switching frequency before diffusion. Then, the diffusion process is terminated.

As a result, as shown in FIGS. 6 and 7, the on / off pattern of the switch 21 can be changed, and the harmonic component (high frequency component) is suppressed. Note that FIG. 6 shows an on / off pattern of the switch 21 before diffusion, and FIG. 7 shows an on / off pattern of the switch 21 after diffusion. In FIGS. 6 and 7, the conditions other than the off time are the same. As shown in FIG. 6, in the on-off pattern before diffusion, the on-time and the off-time are constant. On the other hand, as shown in FIG. 7, in the on-off pattern before diffusion, the on-time is constant, but the off-time is variable (not constant).

By the way, when the overmodulation PWM control is executed, that is, when the modulation factor is a high modulation factor exceeding 100%, the amplitude of the command voltage exceeds the amplitude of the carrier wave as shown in FIGS. 4 and 5. Therefore, the number of times the PWM pulse is turned on and off is reduced. As a result, even if the carrier frequency is randomly changed, the on / off pattern of the PWM pulse is less likely to change. Note that FIG. 4 shows an on / off pattern of the PWM pulse before diffusion, and FIG. 5 shows an on / off pattern of the PWM pulse after diffusion. In FIGS. 4 and 5, the conditions other than the carrier frequency are the same. However, in the present embodiment, since the switching frequency in the detail control is also diffused at the time of high modulation factor, even when the change of the on / off pattern of the PWM pulse is suppressed, the magnetic resonance is suppressed and the electromagnetic noise is suppressed. Is suppressed.

According to the above-described embodiment described in detail above, the following excellent effects can be obtained.

A frequency spreading unit 13 for diffusing at least one of the carrier frequency of the carrier wave and the switching frequency of the switch 21 in duty control is provided. As a result, the armature winding 45 and the field winding 42 can be suppressed from magnetically resonating, and electromagnetic noise can be suppressed.

When the amplitude of the command voltage is large with respect to the system voltage input to the inverter 30, the command voltage exceeds the amplitude of the carrier wave, so that the number of times the PWM pulse is turned on and off is reduced. As a result, even if the carrier frequency of the carrier wave is randomly changed, the change in the on / off pattern of the PWM pulse is small. Therefore, when the overmodulation PWM control is executed, it is decided to diffuse at least the switching frequency in the duty control of the field winding 42. As a result, even when it is difficult to sufficiently change the on / off pattern of the PWM pulse depending on the carrier frequency, electromagnetic noise can be suppressed by diffusing the switching frequency. Further, since it is not necessary to increase the system voltage input to the inverter 30, it is preferable from the viewpoint of the withstand voltage of the inverter 30.

Further, when the overmodulation PWM control is executed, both the carrier frequency and the switching frequency are diffused. This makes it possible to reduce electromagnetic noise as compared with the case where one of the frequencies is diffused.

If both the carrier frequency and the switching frequency are diffused, the power efficiency of the motor 40 may decrease. On the other hand, when the sinusoidal PWM control is executed, the harmonic component in the output voltage to the motor 40 is small and the electromagnetic noise is small as compared with the case where the overmodulation PWM control is performed. Therefore, when the sinusoidal PWM control is executed, only the carrier frequency is diffused. As a result, it is possible to suppress a decrease in the power efficiency of the motor 40 while suppressing electromagnetic noise.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings. In the second embodiment, the following configurations are added in addition to the configurations of the first embodiment. In each of the following embodiments, the parts that are the same or equal to each other are designated by the same reference numerals in the drawings. Further, the configuration already described in the first embodiment will be omitted in the second embodiment.

As shown in FIGS. 4 and 5, when the modulation factor is a high modulation factor exceeding 100%, it is difficult to change the on / off pattern of the PWM pulse even if the carrier frequency is randomly changed. Therefore, in the second embodiment, when the modulation factor is high, the diffusion of the carrier frequency is stopped and the modulation factor is changed to change the on / off pattern of the PWM pulse. This will be explained in detail.

FIG. 9 shows a PWM pulse when the amplitude of the command voltage is increased (that is, when the modulation factor is increased). When the amplitude of the command voltage is increased, the on / off pulse is released in the same phase of the command voltage after the fluctuation, and the on / off pattern of the PWM pulse is changed. That is, different pulse patterns are generated.

FIG. 10 shows a PWM pulse when the amplitude of the command voltage is reduced (that is, when the modulation factor is reduced). When the amplitude of the command voltage is reduced, the on / off pulse increases in the same phase of the command voltage after the fluctuation, and the on / off pattern of the PWM pulse changes. That is, different pulse patterns are generated.

By the way, if only the amplitude of the command voltage is changed, the amplitude of the voltage applied to the armature winding 45 also changes, and the control amount of the motor 40 cannot be kept constant. Therefore, in the second embodiment, in order to keep the controlled amount of the motor 40 constant, the amplitude of the command voltage is changed according to the fluctuation of the system voltage. That is, when the amplitude of the command voltage is increased, the system voltage input to the inverter 30 is lowered according to the amplitude fluctuation of the command voltage to keep the output from the inverter 30 constant. Further, when the amplitude of the command voltage is small, the system voltage is increased according to the amplitude fluctuation of the command voltage to keep the output from the inverter 30 constant.

Next, in addition to the configuration of the first embodiment, a necessary configuration will be described in order to fluctuate the system voltage. As shown in FIG. 11, the control system 100 of the second embodiment includes a converter 70 in addition to the configuration of the first embodiment. The converter 70 includes an input capacitor Ci connected between the input terminals, a reactor Lt connected in series with the input capacitor Ci, a series of switches Sw71 and Sw72, and an output capacitor Cо connected between the output terminals. The series of switches Sw71 and Sw72 is connected in parallel to the output capacitor Cо, and the reactor Lt is connected to the connection point between the switch Sw71 and the switch Sw72. Body diodes D71 and D72 are connected in parallel to the switches Sw71 and Sw72, respectively. In the present embodiment, the switches Sw71 and Sw72 employ IGBTs (insulated gate bipolar transistors), but other switching elements such as MOSFETs may also be adopted.

The converter 70 is a boost converter that boosts the DC voltage of the battery 50, which is a DC power supply connected to the input terminal, that is, the power supply voltage based on the required voltage value. The converter 70 outputs the boosted voltage to the inverter 30. Therefore, the voltage input from the converter 70 to the inverter 30 becomes the system voltage. Specifically, the operation signals g71 and g72 transmitted from the control device 10 control the drive of the switches Sw71 and Sw72, so that the converter 70 boosts the power supply voltage to the required voltage value. The operation signals g71 and g72 are signals generated by the control device 10 according to the required voltage value, and are gate drive signals for controlling the on / off of the switches Sw71 and Sw72.

The control device 10 of the second embodiment includes a converter control unit 14 in addition to the configuration of the first embodiment. The converter control unit 14 generates a required voltage value for the converter 70. Then, the operation signals g71 and g72 are generated based on the required voltage value, and the generated operation signals g71 and g72 are transmitted to the gate terminals of the switches Sw71 and Sw72. As a result, the converter control unit 14 boosts the power supply voltage to the converter 70 and outputs the boosted voltage to the inverter 30 as the system voltage.

Then, in step S104 of the diffusion process, the control device 10 controls the command voltage and the system voltage so that the modulation factor fluctuates within a predetermined fluctuation range. The predetermined fluctuation range is a range in which the modulation factor exceeds 100%, and specifically, is a second modulation factor range (for example, a range of 101% to 125%) in which overmodulation PWM control is performed. Within the fluctuation range, the modulation factor is increased or decreased by several percent. As described above, the control device 10 has a function as a variable unit 15.

The method of varying the modulation factor will be described in more detail. When the modulation factor is changed, the control device 10 changes the amplitude of the command voltage calculated based on the command value. The amplitude of the command voltage calculated based on the command value is referred to as the initial amplitude. The control device 10 varies the amplitude irregularly and discontinuously within a predetermined amplitude range with reference to the initial amplitude. The amplitude range is, for example, a range in which the initial amplitude is increased or decreased by several percent. Further, when fluctuating, it is desirable that the average value of the amplitude after the fluctuation almost coincides with the initial amplitude. The period for varying the amplitude of the command voltage may be different from the period for diffusing (variating) the frequency. Further, in step S104 of the diffusion process of the second embodiment, the control device 10 as the frequency diffusion unit 13 may keep the carrier frequency constant.

Then, in step S104 of the diffusion process, the control device 10 as the converter control unit 14 fluctuates the system voltage so that the control amount of the motor 40 becomes constant according to the amplitude fluctuation of the command voltage. That is, when the amplitude of the command voltage is reduced by the fluctuation unit 15, the control device 10 generates a required voltage value for increasing the system voltage so that the control amount of the motor 40 becomes constant. On the other hand, when the amplitude of the command voltage is increased by the fluctuation unit 15, the control device 10 generates a required voltage value for lowering the system voltage so that the control amount of the motor 40 becomes constant. Since the converter 70 is a boost converter, the system voltage cannot be lowered below the power supply voltage, but if the initial value of the system voltage is set higher than the current voltage in advance, the system voltage can be lowered. Is possible.

According to the second embodiment described above, the following effects are obtained.

At the time of high modulation rate (during overmodulation PWM control), the command voltage becomes larger than the amplitude of the carrier wave, so that it is difficult to change the on / off pattern of the PWM pulse. Therefore, at the time of high modulation rate (during overmodulation PWM control), the amplitude of the command voltage was changed to change the modulation rate. As a result, the on / off pattern of the PWM pulse can be appropriately changed and electromagnetic noise can be suppressed.

The required voltage value for the converter 70, that is, the system voltage was changed so that the control amount of the motor 40 was constant according to the fluctuation of the amplitude of the command voltage. As a result, even if the amplitude of the command voltage is changed, the output waveform can be kept constant and the control amount of the motor 40 can be set according to the command value.

(Third Embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings. In the third embodiment, the following configurations are added in addition to the configurations of the first embodiment or the second embodiment. In each of the following embodiments, the parts that are the same or equal to each other are designated by the same reference numerals in the drawings. Further, the configurations already described in each embodiment will be omitted in the third embodiment.

As shown in FIG. 12, in the diffusion process of the third embodiment, the control device 10 as the frequency spreading unit 13 first has a current amount of the field current flowing through the field winding 42 equal to or higher than the first threshold value. Further, it is determined whether or not the amount of armature current flowing through the armature winding 45 is equal to or greater than the second threshold value (step S301). On the other hand, when the determination result in step S301 is affirmative, the frequency spreading unit 13 spreads the carrier frequency and the switching frequency (step S302).

If the determination result in step S301 is negative, whether the control device 10 as the frequency spreading unit 13 can switch at least one of the carrier frequency before spreading and the switching frequency before spreading based on the request to the motor 40. It is determined whether or not (step S303). The requirement for the motor 40 is a command value for the controlled variable of the motor 40. That is, when the control amount such as the torque and the rotation speed of the motor 40 is changed based on the request to the motor 40, the carrier frequency is for the purpose of realizing the required output or improving the power efficiency. And switching frequency may be switched. In step S303, the switching is determined based on the request to the motor 40.

If the determination result in step S303 is affirmative, the control device 10 diffuses the carrier frequency and the switching frequency (step S302). When the determination result in step S303 becomes affirmative and the carrier frequency and the switching frequency are diffused, the frequency is diffused from the start of switching until a predetermined time elapses. Further, if the timing of switching can be determined in advance, it is desirable to spread the frequency before the switching.

On the other hand, if the determination result in step S303 is negative, the control device 10 determines whether or not switching is performed between the overmodulation PWM control and the sinusoidal PWM control (step S304). That is, it is determined whether or not the modulation factor is 100% or less and larger than 100%, or whether or not it is 100 or less from the time when it is larger than 100%. If the determination result in step S304 is affirmative, the control device 10 diffuses the carrier frequency and the switching frequency (step S302). When the determination result in step S304 becomes affirmative and the carrier frequency and the switching frequency are diffused, the frequency is diffused from the start of switching until a predetermined time elapses. Further, if the timing of switching can be determined in advance, it is desirable to spread the frequency before the switching.

If the determination result in step S304 is negative, the control device 10 performs the processes after step S101. In the third embodiment, the processing order of steps S301, S303, and S304 may be arbitrarily changed. Further, any one or two processes of steps S301, S303, and S304 may be performed, and the other processes may not be performed. Further, the processes of steps S301, S303, and S304 may be performed only when the sine wave PWM control is performed.

According to the third embodiment described above, the following effects are obtained.

When the amount of field current and the amount of armature current are large, electromagnetic noise may be larger than when they are small. The control device 10 as the frequency spreading unit 13 determines when the amount of field current is equal to or greater than the first threshold value and the amount of armature current is equal to or greater than the second threshold value, that is, the determination in step S301. If the result is affirmative, the carrier frequency and switching frequency are diffused to further suppress electromagnetic noise.

When at least one of the carrier frequency and the switching frequency is switched based on the request to the motor 40 (that is, when the frequency itself before diffusion is changed), the tone color changes at the time of switching, which may cause discomfort to the user. There is sex. In addition, electromagnetic noise may increase during switching. Therefore, when the determination result in step S303 is affirmative, that is, when the frequency is switched, the control device 10 as the frequency spreading unit 13 spreads both the carrier frequency and the switching frequency to further suppress electromagnetic noise. And said.

When switching between the overmodulation PWM control and the sinusoidal PWM control, the response may be disturbed at the time of switching, and the electromagnetic noise may increase. Therefore, when the determination result in step S304 is affirmative, that is, when the PWM control is switched, the control device 10 as the frequency spreading unit 13 spreads both the carrier frequency and the switching frequency to further suppress electromagnetic noise. I decided.

(Other embodiments)
The embodiment is not limited to the above embodiment, and may be carried out as follows, for example. In the following, the parts that are the same or equal to each other in each embodiment are designated by the same reference numerals, and the description thereof will be referred to for the portions having the same reference numerals.

-In the above embodiment, at least one of the carrier frequency and the switching frequency may be diffused regardless of the modulation factor. That is, when the sinusoidal PWM control is executed, at least one of the carrier frequency and the switching frequency may be diffused. Similarly, when overmodulation PWM control is being executed, at least one of the carrier frequency and the switching frequency may be diffused.

-In the second embodiment, the converter 70 may not be provided. In this case, it is sufficient to change the modulation factor by changing only the amplitude of the command voltage value.

-In the above embodiment, when the overmodulation PWM control is performed (that is, when the modulation factor is in the second modulation factor range), the modulation factor is changed within a predetermined fluctuation range, but during the sinusoidal PWM control. , The modulation factor may be varied. In this case, it is desirable to change the modulation factor within the range of the first modulation factor.

-In the second embodiment, when the modulation factor is changed, the system voltage may be changed so as to change the modulation factor within a predetermined range without changing the amplitude of the command voltage. Specifically, the required voltage value may be varied. Further, the amplitude of the carrier wave may be varied.

-Although a boost converter is adopted as the converter 70 of the second embodiment, a converter that lowers the power supply voltage or a converter that can perform step-up and step-down may be adopted.

In the third embodiment, the amount of field current flowing through the field winding 42 is less than the first threshold value, or the amount of armature current flowing through the armature winding 45 is less than the second threshold value. In some cases, it is not necessary to spread the frequency.

10 ... control device, 11 ... armature control unit, 12 ... field control unit, 13 ... frequency diffusion unit, 30 ... inverter, 40 ... motor, 42 ... field winding, 45 ... armature winding, 100 ... control system.

Claims (10)

A rotary electric machine applied to a control system (100) including a rotary electric machine (40) having a field winding (42) and an armature winding (45) and an inverter (30) for driving the rotary electric machine. In the control device (10)
An armature control unit (11) that controls the armature current of the armature winding by PWM control that generates a PWM pulse based on a command voltage and a carrier wave for the rotary electric machine and outputs the PWM pulse to the inverter. )When,
A field control unit (12) that controls the field current flowing through the field winding by duty control that changes the on / off time ratio of the input voltage to the field winding.
A frequency spreading unit (13) for diffusing at least one of the carrier frequency of the carrier wave and the switching frequency in the duty control is provided .
The armature control unit is configured to be capable of executing overmodulation PWM control in which the command voltage for the rotary electric machine generates a PWM pulse in a large modulation factor range with respect to the system voltage input to the inverter.
The frequency spreading unit is a control device for a rotary electric machine that spreads at least the switching frequency when the overmodulation PWM control is executed . The first aspect of the present invention includes a variable unit (15) that changes the modulation factor obtained by dividing the command voltage by the system voltage when the overmodulation PWM control is executed within a predetermined fluctuation range. Rotating electric machine control device. The control system boosts or steps down the voltage of the power supply that supplies power to the inverter based on the required voltage value, generates a system voltage to be input to the inverter, and outputs the system voltage to the inverter. Equipped with a converter (70)
A converter control unit (14) that outputs the required voltage value and controls the converter is provided.
The control device for a rotary electric machine according to claim 2 , wherein the fluctuation unit changes the modulation factor by changing at least one of a command voltage for the rotary electric machine and a required voltage value. The frequency spreading unit diffuses the carrier frequency and the switching frequency when the current amount of the field current is equal to or higher than the first threshold value and the current amount of the armature current is equal to or higher than the second threshold value. The control device for a rotary electric machine according to any one of claims 1 to 3 . A rotary electric machine applied to a control system (100) including a rotary electric machine (40) having a field winding (42) and an armature winding (45) and an inverter (30) for driving the rotary electric machine. In the control device (10)
An armature control unit (11) that controls the armature current of the armature winding by PWM control that generates a PWM pulse based on a command voltage and a carrier wave for the rotary electric machine and outputs the PWM pulse to the inverter. )When,
A field control unit (12) that controls the field current flowing through the field winding by duty control that changes the on / off time ratio of the input voltage to the field winding.
A frequency spreading unit (13) for diffusing at least one of the carrier frequency of the carrier wave and the switching frequency in the duty control is provided.
The frequency spreading unit diffuses the carrier frequency and the switching frequency when the current amount of the field current is equal to or higher than the first threshold value and the current amount of the armature current is equal to or higher than the second threshold value. A control device for a rotating electric machine. The armature control unit is configured to be capable of executing sinusoidal PWM control that generates a PWM pulse in a modulation factor range in which the command voltage for the armature winding is equal to or lower than the system voltage input to the inverter.
The control device for a rotary electric machine according to any one of claims 1 to 5 , wherein the frequency spreading unit spreads the carrier frequency or the switching frequency when the sine wave PWM control is executed. The frequency spreading unit spreads the carrier frequency and the switching frequency when at least one of the carrier frequency before spreading and the switching frequency before spreading is switched based on the request to the rotary electric machine. The control device for a rotary electric machine according to any one of claims 1 to 6 . A rotary electric machine applied to a control system (100) including a rotary electric machine (40) having a field winding (42) and an armature winding (45) and an inverter (30) for driving the rotary electric machine. In the control device (10)
An armature control unit (11) that controls the armature current of the armature winding by PWM control that generates a PWM pulse based on a command voltage and a carrier wave for the rotary electric machine and outputs the PWM pulse to the inverter. )When,
A field control unit (12) that controls the field current flowing through the field winding by duty control that changes the on / off time ratio of the input voltage to the field winding.
A frequency spreading unit (13) for diffusing at least one of the carrier frequency of the carrier wave and the switching frequency in the duty control is provided.
The frequency spreading unit spreads the carrier frequency and the switching frequency when at least one of the carrier frequency before spreading and the switching frequency before spreading is switched based on the request to the rotary electric machine. Control device for rotary electric machine. The armature control unit has sinusoidal PWM control that generates a PWM pulse in a modulation factor range in which the command voltage for the armature winding is equal to or lower than the system voltage input to the inverter, and the command voltage for the rotary electric machine. , Overmodulation PWM control that generates PWM pulses in a large modulation factor range with respect to the system voltage, and is configured to be executable.
The one according to any one of claims 1 to 8, wherein the frequency spreading unit diffuses the carrier frequency and the switching frequency when switching between the overmodulation PWM control and the sine wave PWM control. Control device for rotary electric machine. A rotary electric machine applied to a control system (100) including a rotary electric machine (40) having a field winding (42) and an armature winding (45) and an inverter (30) for driving the rotary electric machine. In the control device (10)
An armature control unit (11) that controls the armature current of the armature winding by PWM control that generates a PWM pulse based on a command voltage and a carrier wave for the rotary electric machine and outputs the PWM pulse to the inverter. )When,
A field control unit (12) that controls the field current flowing through the field winding by duty control that changes the on / off time ratio of the input voltage to the field winding.
A frequency spreading unit (13) for diffusing at least one of the carrier frequency of the carrier wave and the switching frequency in the duty control is provided.
The armature control unit has sinusoidal PWM control that generates a PWM pulse in a modulation factor range in which the command voltage for the armature winding is equal to or lower than the system voltage input to the inverter, and the command voltage for the rotary electric machine. , Overmodulation PWM control that generates PWM pulses in a large modulation factor range with respect to the system voltage, and is configured to be executable.
The frequency spreading unit is a control device for a rotary electric machine that spreads the carrier frequency and the switching frequency when switching between the overmodulation PWM control and the sine wave PWM control.

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