JP7187818B2 - Rotating electric machine control device - Google Patents

Description

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

2. Description of the Related Art Conventionally, pulse width modulation control (PWM control) is performed on power converters (inverters) used in rotating electric machines. Some rotary electric machines that are PWM-controlled drive an inverter with a carrier frequency of 10.0 kHz or less due to problems such as heat generation of circuit elements. Since this frequency band is included in the human audible frequency band, the electromagnetic noise based on the carrier wave may give discomfort to the driver.

Therefore, a control device for controlling the driving of a PWM inverter has been proposed so as to reduce the electromagnetic noise of the rotating electrical machine (for example, Patent Literature 1). In the control device of Patent Literature 1, the carrier frequency is randomly changed (spread) to reduce the electromagnetic noise of the rotating electric machine.

JP 2012-171369 A

When the electromagnetic noise is reduced by the above-described method, the electromagnetic noise due to the carrier wave is not noticeable when the noise other than the electromagnetic noise is large, such as when the vehicle is running. However, for example, when the engine is in an idling state and the vehicle is stopped, the electromagnetic noise becomes relatively loud and may make the driver feel uncomfortable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a control apparatus for a rotating electrical machine that obscures electromagnetic noise that may occur when the rotating electrical machine is driven.

In order to solve the above problems, a first means is a rotating electrical machine control device applied to a vehicle having an internal combustion engine, a rotating electrical machine, and an inverter for driving the rotating electrical machine, in which a PWM pulse is generated based on a carrier wave. and outputting the PWM pulse to the inverter to control the rotating electric machine, the frequency being within a predetermined frequency setting range, and the internal combustion engine being in a predetermined driving state The fundamental frequency of the carrier wave is set according to a frequency at which the sound pressure level of noise generated in the vehicle in which the rotary electric machine is in a predetermined power generation state is equal to or higher than a threshold.

The sound pressure level of carrier-based electromagnetic noise is generally highest at the fundamental frequency of the carrier. Therefore, the fundamental frequency of the carrier wave is set according to the frequency at which the sound pressure level of the noise generated in the vehicle in which the internal combustion engine is in a predetermined driving state and the rotating electric machine is in a predetermined power generating state is equal to or higher than the threshold. . As a result, the electromagnetic noise can be mixed with the noise of the vehicle and made inconspicuous.

The block diagram which shows a rotary electric machine unit. The figure which shows the electric structure of a rotating electric machine unit. (a) is a side view showing the arrangement of sound measuring microphones, and (b) is a plan view showing the arrangement of the sound measuring microphones. FIG. 4 is a diagram showing the spread width of the frequency of the carrier wave; (a) shows the waveform of electromagnetic noise in the conventional art, and (b) shows the waveform of electromagnetic noise in the present embodiment.

Embodiments will be described below with reference to the drawings. In addition, in each of the following embodiments, the same or equivalent portions are denoted by the same reference numerals in the drawings. A rotary electric machine unit 10 according to the present embodiment will be described. The rotary electric machine unit 10 is applied to a vehicle 100 such as a hybrid vehicle having an engine 101 as an internal combustion engine as shown in FIG.

The rotary electric machine unit 10 includes an AC motor (hereinafter referred to simply as a motor 20 ) as a rotary electric machine, inverters 31 and 32 as power converters, and an ECU 40 as a controller that controls the operation of the motor 20 . The rotary electric machine unit 10 is a generator with a motor function, and is configured as an electromechanically integrated ISG (Integrated Starter Generator).

A rotating shaft of the motor 20 is drivingly connected to an engine output shaft (not shown) of the engine 101 by a belt. The rotation of the engine output shaft causes the rotation shaft of the motor 20 to rotate, while the rotation of the rotation shaft of the motor 20 causes the engine output shaft to rotate. That is, the rotary electric machine unit 10 has a power generation function of generating power (regenerative power generation) by rotating the engine output shaft and the axle, and a power running function of applying rotational force to the engine output shaft. The motor 20 also includes a stator having two sets of three-phase windings and a rotor having eight pole pairs of magnet portions (permanent magnets or field windings).

Here, the electrical configuration of the rotating electric machine unit 10 will be described with reference to FIG. 2 . In FIG. 2, two sets of three-phase windings 21a and 21b are shown as the stator windings 21 (armature windings) of the motor 20. The three-phase windings 21a are the U-phase winding and the V-phase winding. and W-phase windings, and the three-phase winding 21b consists of an X-phase winding, a Y-phase winding and a Z-phase winding. A first inverter 31 and a second inverter 32 are provided for each of the three-phase windings 21a and 21b. The inverters 31 and 32 are composed of a full-bridge circuit having the same number of upper and lower arms as the number of phases of the phase windings. The energized current is adjusted in each phase winding.

A DC power supply 50 and a smoothing capacitor 51 are connected in parallel to each of the inverters 31 and 32 . The DC power supply 50 is configured by, for example, an assembled battery in which a plurality of cells are connected in series.

The ECU 40 includes a microcomputer including a CPU and various memories, and has various functions. Various functions are realized by the CPU executing programs stored in various memories and the like. Note that these functions may be realized by an electronic circuit that is hardware, or at least a part of them may be realized by software, that is, processing executed on a computer.

For example, the ECU 40 performs energization control by turning on/off each switch in the inverters 31 and 32 based on various detection information in the rotary electric machine unit 10 and requests for power running driving and power generation. The detection information of the rotary electric machine unit 10 includes, for example, the rotation angle of the rotor (electrical angle information) detected by an angle detector such as a resolver, the power supply voltage (inverter input voltage) detected by a voltage sensor, the current sensor contains the conducting current of each phase detected by ECU 40 generates and outputs an operation signal for operating each switch of inverters 31 and 32 . Note that the request for power generation is a request for regenerative drive when the rotary electric machine unit 10 is used as a power source for a vehicle, for example.

The first inverter 31 includes a series connection body of an upper arm switch Sp and a lower arm switch Sn for each of the three phases, ie, the U phase, the V phase, and the W phase. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the DC power supply 50, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the DC power supply 50. . One ends of the U-phase winding, the V-phase winding, and the W-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. These phase windings are star-connected (Y-connected), and the other ends of the phase windings are connected to each other at a neutral point.

The second inverter 32 has a configuration similar to that of the first inverter 31, and in three phases consisting of the X-phase, the Y-phase and the Z-phase, serially connected bodies of an upper arm switch Sp and a lower arm switch Sn are respectively connected. I have. The high potential side terminal of the upper arm switch Sp of each phase is connected to the positive terminal of the DC power supply 50, and the low potential side terminal of the lower arm switch Sn of each phase is connected to the negative terminal (ground) of the DC power supply 50. . One end of an X-phase winding, a Y-phase winding, and a Z-phase winding are connected to intermediate connection points between the upper arm switch Sp and the lower arm switch Sn of each phase. These phase windings are star-connected (Y-connected), and the other ends of the phase windings are connected to each other at a neutral point.

Next, a current control process for controlling each phase current of the U, V, and W phases will be described. The ECU 40 determines U-phase, V-phase, and W-phase command voltages based on a powering torque command value or a power generation torque command value for the rotary electric machine unit 10 and an electrical angular velocity obtained by time differentiation of the electrical angle. Note that the power generation torque command value is a regenerative torque command value, for example, when the rotary electric machine unit 10 is used as a power source for a vehicle.

Then, the ECU 40 generates an operation signal for the first inverter 31 based on the three-phase command voltage using a well-known triangular wave carrier comparison method. Specifically, the ECU 40 performs switching operation of the upper and lower arms in each phase by PWM control based on a magnitude comparison between a signal obtained by standardizing the three-phase command voltage with the power supply voltage and a carrier signal as a carrier wave such as a triangular wave signal. Generate a signal (duty signal). Then, the ECU 40 turns on and off the three-phase switches Sp, Sn in the inverters 31, 32 based on the generated switch operation signals. Since the current control processing on the X, Y, and Z phase sides is the same, the description is omitted. Thereby, the motor 20 is controlled. As described above, the ECU 40 functions as a PWM control section 41 that generates PWM pulses based on carrier waves and outputs the PWM pulses to the inverters 31 and 32 to control the motor 20 .

By the way, in the rotary electric machine unit 10 of the present embodiment, the carrier frequency of the carrier wave is set to 10.0 kHz or less in consideration of the heat generation of the circuit elements of the inverters 31 and 32 and the like. Since this frequency band is included in the human audible frequency band, the electromagnetic noise based on the carrier wave may give discomfort to the driver. In particular, when the engine 101 is in an idling state and the vehicle 100 is stopped, and the noise itself in the vehicle 100 is small compared to when the vehicle is running based on the drive of the engine 101, the electromagnetic noise is relative. It may become large and conspicuous. Therefore, in order to make the electromagnetic noise inconspicuous, the system is configured as follows.

First, the electromagnetic noise of the rotary electric machine unit 10 based on carrier waves will be described. Electromagnetic noise is the noise of the rotating electric machine unit 10 that is measured under predetermined measurement conditions. The predetermined measurement condition is, for example, an idling condition, which drives the motor 20 with a low load. For example, the conditions are such that the number of revolutions of the motor 20 is 1800 (equivalent to 750 rpm in terms of the number of revolutions of the engine 101), the voltage applied to the rotating electric machine unit 10 is 14.5V, and the output current is 25A. Spectrum analysis of the measured electromagnetic noise reveals that the carrier-based electromagnetic noise has the highest sound pressure level at the fundamental frequency of the carrier. Also, the sound pressure level of the n-th harmonic (n is 2 or more) of the carrier wave is higher than that of the other frequencies (excluding the fundamental frequency).

Here, a method for measuring electromagnetic noise will be described. The electromagnetic noise (magnetic noise evaluation result) of the rotary electric machine unit 10 is acquired in the actual vehicle environment. Specifically, in a soundproof room or the like, the rotary electric machine unit 10 (or the motor 20) is evaluated individually. At that time, the sound measuring microphone is arranged in consideration of the arrangement (angle and position) of the rotary electric machine unit 10 in the vehicle 100 and the position of the passenger (seat position etc.).

For example, as shown in FIG. 3A, at a position about a predetermined distance (for example, 30 cm) away from the rotating electric machine unit 10, a sound measurement is performed above a predetermined angle (for example, 45 degrees) above the horizontal plane of the rotating electric machine unit 10. Microphones 700a-700c are arranged. At that time, as shown in FIG. 3B, a plurality of (three in this embodiment) sound measuring microphones 700a to 700c can be provided at intervals of a predetermined angle (for example, 45 degrees) around the rotary electric machine unit 10. desirable. In this case, it is desirable that the plurality of sound measuring microphones 700a to 700c be arranged along the axial direction of the rotating shaft of the motor 20 on the radially outer side of the rotating shaft. It is desirable to acquire the average of the sound pressure levels measured by the plurality of sound measuring microphones 700a to 700c as the electromagnetic noise measurement result.

Next, noise in vehicle 100 will be described. The noise in the vehicle 100 in this embodiment is the noise generated in the vehicle 100 when the engine 101 is in a predetermined driving state. More specifically, noise generated in vehicle 100 when engine 101 is in an idling state and vehicle 100 is stopped is targeted. This is because, in this state, the noise generated from the vehicle equipment other than the rotary electric machine unit 10 is considered to be the smallest. Note that when the engine 101 is in a predetermined driving state, the rotating electric machine unit 10 is in a predetermined power generation state. The predetermined power generation state is a state in which the rotating electric machine unit 10 generates power without performing PWM control. ).

Here, a method for measuring noise in vehicle 100 will be described. Noise generated by the engine 101 is measured in an actual vehicle environment. As described above, while the vehicle 100 is stopped and the engine 101 is in an idling state (no-load operation state), the rotary electric machine unit 10 is caused to generate power without PWM control, and the noise of the engine 101 alone is measured. That is, while the engine 101 is being driven, the noise is measured by stopping the driving of the components other than the engine 101 so that the noise generated by the vehicle equipment other than the rotating electric machine unit 10 is minimized. At that time, a single evaluation of the engine 101 is performed in the same manner as when measuring the electromagnetic noise of the rotary electric machine unit 10 . That is, considering the arrangement angle of the engine 101 in the vehicle 100, the installation position, the position of the occupant, etc., at a position about a predetermined distance (for example, 30 cm) away from the engine 101, a predetermined angle (for example, 45 degrees), the sound measuring microphones 700a to 700c are arranged above. At that time, a plurality of (three in this embodiment) sound measuring microphones 700a to 700c are provided at intervals of a predetermined angle (for example, 45 degrees) around the engine 101, and the average of the measured sound pressure levels is calculated as the noise in the vehicle 100. It is desirable to acquire it as a measurement result of The noise measured in this way is hereinafter simply referred to as noise in vehicle 100 .

Next, frequency spectrum analysis is performed on the noise in the vehicle 100 measured by the method described above. Then, within a predetermined frequency setting range (hereinafter simply referred to as a setting range), a frequency at which the sound pressure level of noise in vehicle 100 is equal to or higher than a threshold is specified. The threshold may be set based on the sound pressure level of noise in the vehicle 100 within the set range, for example, a value corresponding to the top few percent of the sound pressure level of the noise in the vehicle 100 within the set range (eg, 45 dB). is set.

More preferably, within the set range, one or a plurality of frequencies at which the sound pressure level of noise in the vehicle 100 is equal to or higher than the threshold and at which the maximum value changes from increasing to decreasing (the maximum value changing from positive to negative slope) is specified. do. Hereinafter, in the noise in the vehicle 100, the point specified by the maximum value of the sound pressure level and the frequency at which the maximum value is obtained will be referred to as a maximum point. In the set range, if the number of maximum points with a sound pressure level equal to or higher than the threshold is greater than a predetermined number, the top several percent of maximum points with the highest sound pressure level are identified.

Note that if the setting range is set in units of several kHz, a difference of less than 0.1 kHz can be considered as an error, and thus a difference of less than 0.1 kHz is not considered in this embodiment. At that time, digits less than 0.1 kHz may be rounded down, rounded up, or rounded off. For example, when the frequency at which the sound pressure level is equal to or higher than the threshold is in the range of 5.05 to 5.34 kHz, the frequencies at which the sound pressure level is equal to or higher than the threshold are 5.1 kHz, 5.2 kHz, and 5.3 kHz.

Here, a predetermined frequency setting range (setting range) will be described. The setting range is set at least within the human audible frequency band. The audible frequency band is generally in the range of about 0.02 kHz (20 Hz) to 10.0 kHz. Also in this embodiment, the audible frequency band is described as being in the range of 0.02 kHz to 10.0 kHz.

By the way, as described above, the sound pressure level of the electromagnetic noise is higher at the n-th harmonic of the carrier wave (hereinafter simply referred to as harmonic) as compared with other frequencies. Also, if the fundamental frequency of the carrier wave becomes too low, the controllability of the motor 20 will deteriorate. For this reason, it is desirable that the setting range be within a frequency band in which the frequency of harmonics of the carrier wave is higher than the human audible frequency band. Specifically, if the fundamental frequency is set in a frequency band higher than 5.0 kHz, harmonics (second harmonics and higher harmonics) are higher than 10.0 kHz and fall outside the audible frequency band. Therefore, in this embodiment, the setting range is defined in a frequency band greater than 5.0 kHz.

In addition, if the fundamental frequency of the carrier wave is increased, heat generation and capacitor ripple occur in the switching elements, which may cause an abnormality in the rotating electrical machine unit 10 . Therefore, it is desirable that the setting range be within a range in which the operation of the rotary electric machine unit 10 is guaranteed. In this embodiment, when the motor 20 is powered and the vehicle 100 is driven, the fundamental frequency of the carrier wave is 7.0 kHz. Therefore, the setting range of this embodiment is set to 7.0 kHz or less.

In summary, the setting range is set to 5.0 kHz to 7.0 kHz. Within this set range, one or more frequencies at which the sound pressure level is equal to or higher than the threshold are specified. More preferably, one or a plurality of frequencies at which the sound pressure level is equal to or higher than the threshold and has a maximum value within the set range are specified. At that time, when the number of frequencies satisfying the above condition is more than a predetermined number (for example, 100 or more), the top several percent of frequencies are specified in descending order of the sound pressure level. This specified frequency is hereinafter referred to as a frequency that satisfies the first condition.

By the way, as will be described later, in this embodiment, the fundamental frequency of the carrier is spread. For this reason, it is desirable that the upper limit of the fundamental frequency after diffusion is within the range in which the operation of the rotary electric machine unit 10 is guaranteed, and that a sufficient diffusion width can be secured. In addition, heat generation can be suppressed when the fundamental frequency of the carrier is low compared to when the fundamental frequency is high. That is, it is desirable to make the fundamental frequency as small as possible within the set range. Therefore, it is desirable to determine the lowest frequency among the frequencies satisfying the first condition as the fundamental frequency.

Also, if the fundamental frequency is a multiple of the number of phases or the number of pole pairs of the motor 20, resonance may occur and electromagnetic noise may increase. Therefore, it is desirable to set the fundamental frequency to a frequency that is different from a multiple of the number of phases and a multiple of the number of pole pairs of the motor 20 . That is, when there are a plurality of frequencies that satisfy the first condition, the frequency that satisfies the first condition is a frequency that is different from a multiple of the number of phases and a multiple of the number of pole pairs of the motor 20 and is the smallest frequency among them. should be determined as the fundamental frequency.

That is, the motor 20 of this embodiment includes a stator having two sets of three-phase windings and a rotor having eight pole pairs of magnet portions (permanent magnets or field windings). Therefore, in this embodiment, for example, if the frequencies satisfying the first condition are 5.1 kHz, 5.3 kHz, 6.0 kHz, and 6.7 kHz in ascending order, the fundamental frequency is set to 5.3 kHz. is preferred.

Then, the frequency spreader 42 spreads the fundamental frequency of the carrier by a predetermined spreading width (Y shown in FIG. 4) centering on the fundamental frequency (X shown in FIG. 4) set (determined) as described above. Let In this case, it is desirable that the upper limit of the fundamental frequency after spreading is within the range in which the operation of the rotary electric machine unit 10 is guaranteed. That is, it is desirable to spread the fundamental frequency of the carrier so that the upper limit of the fundamental frequency after spreading is 7.0 kHz or less. For example, if the fundamental frequency before spreading is 5.3 kHz, it is desirable to spread the fundamental frequency within the range of 3.6 to 7.0 kHz centering on 5.3 kHz.

When the fundamental frequency is diffused, the frequency spreading unit 42 spreads the fundamental frequency so that the sound pressure level of the electromagnetic noise based on the carrier wave is equal to or lower than the sound pressure level of the noise in the vehicle 100 at each fundamental frequency after spreading. diffuse. More specifically, the higher the frequency (selection rate) of the fundamental frequency after diffusion, the higher the sound pressure level at the fundamental frequency. On the other hand, the lower the frequency of selection of the fundamental frequency after diffusion, the lower the sound pressure level at the fundamental frequency. Therefore, the frequency spreader 42 selects the fundamental frequencies after diffusion so that the sound pressure level of the electromagnetic noise based on the carrier wave is equal to or lower than the sound pressure level of the noise in the vehicle 100 at each fundamental frequency after diffusion. Set the frequency (selection rate).

By the way, the sound pressure level of noise in vehicle 100 is not necessarily high at frequencies near the frequency satisfying the first condition. In particular, there is a possibility that the sound pressure level of noise in vehicle 100 decreases as the distance from the frequency that satisfies the first condition increases. Therefore, as shown in FIG. 4, the frequency spreading section 42 is designed so that the selectivity is not uniform within a predetermined spreading width. For example, the frequency spreading section 42 makes it easier to set the post-spreading fundamental frequency (higher selectivity) as the frequency difference from the pre-spreading fundamental frequency (X in FIG. 4) is smaller. That is, the sound pressure level of the electromagnetic noise tends to decrease as the frequency difference from the fundamental frequency before diffusion increases. In FIG. 4, an arrow Y indicates a range that can be set as the fundamental frequency after spreading. As a result, the sound pressure level of electromagnetic noise based on the carrier wave is likely to be equal to or lower than the sound pressure level of the noise in vehicle 100 at each fundamental frequency after diffusion. In particular, when the fundamental frequency before diffusion can take a maximum value, the sound pressure level of the electromagnetic noise based on the carrier wave tends to be equal to or lower than the sound pressure level of the noise in vehicle 100 at each fundamental frequency after diffusion.

Next, the operation when the fundamental frequency of the carrier wave is set as in this embodiment will be described in comparison with the conventional example. In FIG. 5, noise in vehicle 100 is indicated by a dashed line. As shown in FIG. 5, in the range of 5.0 kHz to 7.0 kHz, the sound pressure level of noise in the vehicle 100 is above the threshold at 5.3 kHz and 6.0 kHz. In the conventional example shown in FIG. 5(a), 4.2 kHz is the fundamental frequency of the carrier wave (before spreading), and the frequency is spread in the range of 3.2 to 5.2 kHz. In FIG. 5(a), the electromagnetic noise (after diffusion) based on the carrier wave is indicated by a solid line.

In the conventional example, as shown in FIG. 5A, at 4.2 kHz, the sound pressure level of noise in the vehicle 100 is neither above the threshold nor at the maximum point. At 4.2 kHz, the sound pressure level of the carrier-based electromagnetic noise is higher than the sound pressure level of the noise in the vehicle 100 . Therefore, in the conventional example, the electromagnetic noise at the fundamental frequency (4.2 kHz) tends to stand out.

Further, in the conventional example, the second harmonic of the carrier wave, that is, the frequency (8.4 kHz) that is twice the fundamental frequency (4.2 kHz) in the conventional example is within the audible frequency band, and The sound pressure level of electromagnetic noise is higher than the noise in vehicle 100 . For this reason, electromagnetic noise based on the harmonics of the carrier wave is conspicuous and may make the driver feel uncomfortable.

FIG. 5B shows the electromagnetic noise based on the carrier wave when this embodiment is applied with a solid line. FIG. 5(b) shows the electromagnetic noise when the fundamental frequency of the carrier wave (before spreading) is 5.3 kHz and the frequency of the carrier wave is spread in the range of 3.6 to 7.0 kHz.

As shown in FIG. 5(b), at 5.3 kHz, the sound pressure level of the noise in the vehicle 100 is above the threshold and is at the maximum point. Then, the electromagnetic noise based on the carrier wave in the case of applying the present embodiment is lower than the noise in the vehicle 100 at the fundamental frequency (5.3 kHz). Therefore, in this embodiment, the electromagnetic noise at the fundamental frequency (5.3 kHz) is less noticeable.

Further, in the present embodiment, among the fundamental frequencies (3.6 to 7.0 kHz range) after diffusion, the electromagnetic noise has a lower sound pressure level than the noise in the vehicle 100 at most frequencies. .

Further, when the configuration of this embodiment is applied, the harmonics of the carrier wave are outside the audible frequency band. Therefore, even if the sound pressure level of the electromagnetic noise based on the harmonics of the carrier wave is higher than the noise in the vehicle 100, it is difficult for the driver to notice it. The electromagnetic noise based on the harmonics of the carrier wave after diffusion is also almost outside the audible frequency band or is below the sound pressure level of the noise in the vehicle 100, so that it is difficult for the driver to notice.

According to the embodiment detailed above, the following excellent effects can be obtained.

The sound pressure level of carrier-based electromagnetic noise is generally highest at the fundamental frequency of the carrier. Therefore, within the set range, the fundamental frequency of the carrier wave is set according to the frequency at which the sound pressure level of the noise in the vehicle 100 is equal to or higher than the threshold. More specifically, the fundamental frequency of the carrier wave is set in accordance with the frequency at which the sound pressure level of the noise in the vehicle 100 is equal to or higher than the threshold value and at which the maximum value is reached within the predetermined frequency setting range. Thereby, electromagnetic noise can be made inconspicuous. In particular, when the fundamental frequency of the carrier wave is set in accordance with the frequency of the maximum value, the waveform of the electromagnetic noise resembles the waveform of the noise in the vehicle 100, making it inconspicuous.

The sound pressure level of the electromagnetic noise based on the carrier wave also increases at the harmonic frequencies of the carrier wave. Therefore, the fundamental frequency of the carrier wave is set in a frequency band in which the frequency of the harmonics of the carrier wave is higher than the human audible frequency band. As a result, the electromagnetic noise based on the harmonics of the carrier wave is higher than the human audible frequency band, so that the electromagnetic noise can be made less conspicuous.

The ECU 40 spread the fundamental frequency of the carrier. Therefore, the sound pressure level of the electromagnetic noise at the fundamental frequency of the carrier wave can be reduced to make it less conspicuous. By the way, when the fundamental frequency of the carrier wave is diffused, the sound pressure level of the electromagnetic noise at each fundamental frequency after diffusion becomes higher than when it is not diffused. On the other hand, even if the sound pressure level of noise in vehicle 100 is high at the fundamental frequency before diffusion, the sound pressure level of noise in vehicle 100 is not necessarily high at the fundamental frequency after diffusion. In particular, the sound pressure level of the noise in the vehicle 100 may be lower the farther away from the pre-diffusion frequency. Therefore, the frequency spreader 42 makes it easier to set the post-spreading fundamental frequency as the frequency difference from the pre-spreading fundamental frequency is smaller. As a result, with the sound pressure level of the electromagnetic noise at the fundamental frequency before diffusion being the maximum, the smaller the frequency difference from the fundamental frequency before diffusion, the higher the sound pressure level of the electromagnetic noise tends to be. In particular, when the fundamental frequency of the carrier wave is set in accordance with the frequency of the maximum value, the waveform of the electromagnetic noise resembles the waveform of the noise in the vehicle 100, making it inconspicuous.

If the fundamental frequency of the carrier wave is increased, circuit elements such as switching elements and capacitor ripples may generate heat. By the way, the motor 20 is designed in advance so that the motor 20 does not malfunction even if the circuit elements generate heat as long as the fundamental frequency of the carrier wave is equal to or lower than that set when the motor 20 is powered. Therefore, the upper limit of the fundamental frequency after spreading is made equal to or lower than the fundamental frequency of the carrier wave set when the motor 20 is powered. As a result, it is possible to prevent abnormalities in the motor 20 due to excessive heat generation of the circuit elements.

If the sound pressure level of the electromagnetic noise based on the carrier wave is higher than the sound pressure level of the noise in the vehicle 100, the electromagnetic noise may be noticed. Therefore, the frequency spreading unit 42 spreads the fundamental frequency so that the sound pressure level of the electromagnetic noise based on the carrier wave is equal to or lower than the sound pressure level of the noise in the vehicle 100 at the fundamental frequency. This makes it possible to appropriately obscure the electromagnetic noise.

If the fundamental frequency of the carrier wave is a multiple of the number of phases or the number of pole pairs of the motor 20, resonance may occur and electromagnetic noise may increase. Therefore, the fundamental frequency of the carrier wave is set so as not to be a multiple of the number of phases and a multiple of the number of pole pairs, thereby reducing electromagnetic noise.

When the vehicle 100 is stopped and the engine 101 is in an idling state, the noise in the vehicle 100 is smaller than when the vehicle is running, but the electromagnetic noise is relatively large. , the electromagnetic noise becomes most noticeable. Therefore, noise in vehicle 100 is measured when vehicle 100 is stopped and engine 101 is in an idling state. As a result, the electromagnetic noise can be made inconspicuous in any state while the engine 101 is running.

(Other embodiments)
The present invention is not limited to the above embodiment, and may be implemented as follows, for example. In addition, below, the same code|symbol is attached|subjected to the part which is mutually the same or equivalent in each embodiment, and the description is used about the part of the same code|symbol.

- In the above embodiment, if there is no frequency equal to or higher than the threshold within the set range (or if there is no maximum point), the frequency at which the sound pressure level reaches the maximum value within the set range may be set as the fundamental frequency.

- In the above-described embodiment, the threshold is set based on the sound pressure level of the noise in the vehicle 100 within the set range, but it may be set based on the sound pressure level that people find uncomfortable. For example, 50 dB may be set as the threshold.

- In the above-described embodiment, it is not necessary to match the fundamental frequency with the frequency that satisfies the first condition.

- In the above-described embodiment, the fundamental frequency of the carrier may be set based on the noise smoothed waveform of the measured vehicle 100 in consideration of the possibility of errors and erroneous detection.

- In the above embodiment, the lower limit of the diffusion width may be within a predetermined frequency setting range. For example, the fundamental frequency may be spread within the range of 5.1 kHz to 5.5 kHz. According to this, the frequency of the second harmonic of the fundamental frequency after spreading does not fall within the audible frequency band. Therefore, the electromagnetic noise can be made inconspicuous.

In the above embodiment, the frequency spreader 42 is more likely to set the post-spreading fundamental frequency as the difference in frequency from the pre-spreading fundamental frequency is smaller, but this need not be the case. Spreading may be performed so that the average of the fundamental frequency after spreading matches the fundamental frequency before spreading, or it may be spread randomly.

As the basic frequency in the above embodiment, a frequency different from the multiple of the number of phases provided in the motor 20 and the multiple of the number of pole pairs of the magnet unit is set, but they may be the same. For example, even if the fundamental frequency is a multiple of the number of phases or a multiple of the number of pole pairs of the magnet unit, if the sound pressure level of the electromagnetic noise at the fundamental frequency is lower than the sound pressure level of the noise in the vehicle 100, the good too.

- In the above embodiment, any frequency may be set as the fundamental frequency out of the frequencies that satisfy the first condition.

DESCRIPTION OF SYMBOLS 20... Motor, 31... 1st inverter, 32... 2nd inverter, 40... ECU, 41... PWM control part, 100... Vehicle, 101... Engine.

Claims (7)

In a rotating electrical machine control device (40) applied to a vehicle (100) including an internal combustion engine (101), a rotating electrical machine (20), and inverters (31, 32) for driving the rotating electrical machine,
A carrier wave is used to generate a PWM pulse that is an operation signal for the inverter from the waveform of the command voltage to the rotating electric machine, the PWM pulse is output to the inverter, and each switch of the inverter is operated by the PWM pulse. A PWM control unit (41) that controls the current supplied to the rotating electrical machine by performing on/off control to drive the rotating electrical machine ,
The carrier wave has the same waveform that is repeated a plurality of times in succession,
The PWM control unit generates a PWM pulse by comparing a waveform of a command voltage to the rotating electric machine and a waveform of a carrier wave,
A sound pressure level of the noise of the internal combustion engine, which is a frequency within the human audible frequency band and is generated in the vehicle in which the internal combustion engine is in an idling state and the rotating electric machine is in a power generation state, is equal to or higher than a threshold. The set frequency is set according to the frequency,
A control device for a rotating electric machine, wherein the frequency of the carrier wave is determined based on the set frequency. 2. The control device for a rotary electric machine according to claim 1, wherein the set frequency is set in accordance with a frequency at which the sound pressure level of the noise is equal to or higher than a threshold value and at which the sound pressure level is a maximum value or a maximum value. 3. The rotating electric machine control according to claim 1, wherein the set frequency is set such that a frequency that is n times (n is an arbitrary natural number) the set frequency is higher than the audible frequency band. Device. A frequency spreading unit (42) that spreads the frequency based on the set frequency and determines it as the frequency of the carrier wave,
4. The frequency spreader according to any one of claims 1 to 3, wherein when spreading, the frequency spreader spreads the frequencies so that the frequency closer to the set frequency has a higher probability of being determined as the frequency of the carrier wave. Rotating electric machine control device. 5. The control device for a rotating electrical machine according to claim 4, wherein the upper limit frequency of said carrier wave determined by said frequency spreader is equal to or lower than the frequency of said carrier wave set during power running driving of said rotating electrical machine. The frequency of the carrier wave is determined so that the sound pressure level of the electromagnetic noise based on the carrier wave is equal to or lower than the sound pressure level of the noise at each frequency determined as the frequency of the carrier wave. 6. The controller for a rotating electrical machine according to claim 4, wherein the frequencies are spread by adjusting the probability of determining each frequency. The rotation according to any one of claims 1 to 6, wherein the set frequency is set to a frequency different from a multiple of the number of phases of the armature winding of the rotating electric machine and a multiple of the number of pole pairs of the magnet unit. Electrical control device.

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