JP5659945B2 - Control device for rotating electrical machine - Google Patents

Description

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

  Generally, a rotating electrical machine mounted on an electric vehicle such as a hybrid vehicle is a three-phase synchronous type including a rotor made of a permanent magnet and a stator including U-phase, V-phase, and W-phase stator coils. . The hybrid vehicle is provided with a control device that controls a voltage applied to the rotating electrical machine using an inverter including a plurality of switching elements.

  In the control of a three-phase synchronous rotating electric machine, in order to create a rotating magnetic field, an inverter switching pattern is usually created depending on the electrical angle. For example, in synchronous PWM (Pulse Width Modulation) control, a multiple of 3 carriers (hereinafter referred to as carriers) are introduced per electrical angle cycle of the rotating electrical machine, and the electrical angle of the rotating electrical machine and the carrier are synchronized. Then, the switching control signal is created by comparing the waveform of the voltage command with the waveform of the carrier. According to the synchronous PWM control, even if the number of carrier cycles is reduced, it is easy to ensure the positive / negative symmetry of the pulse width voltage, so that stable control is possible.

  That is, according to the synchronous PWM control, the carrier frequency can be lowered, and the switching loss and heat generation due to switching can be reduced. For this reason, it becomes possible to improve a fuel consumption performance. However, as a contradiction, when the carrier frequency is lowered, electromagnetic noise is likely to occur. Moreover, using the same frequency increases the noise level near that frequency.

  As a technique related to the present invention, in Patent Document 1, synchronous PWM is applied only to a region where suppression of element temperature rise is necessary, and asynchronous PWM having a high carrier frequency is applied to a region where it is not necessary. It is disclosed that the temperature rise in the inverter is suppressed by avoiding the generation of electromagnetic noise as much as possible by properly using both.

  Patent Document 2 discloses that PWM processing is performed by combining carrier frequencies to disperse specific frequency components resulting from the carrier frequency and reduce noise. Patent Document 2 discloses that the switching frequency of the switching element is reduced and the loss is reduced by lowering the carrier frequency in a high load state where the output current is large and increasing the frequency in a low load state where the output current is small. Is disclosed.

JP 2010-246207 A JP 2006-217776 A

  Meanwhile, in the field of electric vehicles and the like, further improvements are required for suppressing electromagnetic noise and suppressing heat generation due to switching of the inverter while maintaining good controllability. That is, the conventional techniques including the technique of the above-mentioned patent document still have room for improvement in terms of both the suppression of electromagnetic noise and the suppression of heat generation by switching.

  That is, an object of the present invention is to provide a control device for a rotating electrical machine capable of achieving both higher levels of suppression of electromagnetic noise and suppression of heat generation by switching while maintaining good controllability.

  A control device for a rotating electrical machine according to the present invention is a control device for a rotating electrical machine that controls a voltage applied to the rotating electrical machine using an inverter including a plurality of switching elements, and performs switching based on a comparison between a voltage command and a carrier wave. A signal generation unit that generates a switching control signal of the element, a carrier wave control unit that sets a reference frequency of the carrier wave based on a predetermined number of synchronizations and the rotation number of the rotating electrical machine, Based on the current command, the frequency of the carrier wave is switched to a high frequency that is an integer multiple of the reference frequency, while in the high current phase region where the current command is high, the high current phase region corresponding to the same switching element is continuously high. It is characterized by not switching to the frequency.

  Alternatively, a control device for a rotating electrical machine according to the present invention is based on a comparison between a voltage command and a carrier wave in a control device for a rotating electrical machine that controls a voltage applied to the rotating electrical machine using an inverter including a plurality of switching elements. A carrier generation unit that generates a switching control signal for the switching element, a carrier wave control unit that sets a reference frequency of the carrier wave based on a predetermined number of synchronizations and a rotation number of the rotating electrical machine, Switches the carrier frequency to a high frequency that is an integer multiple of the reference frequency based on the current command, but does not switch to the high frequency continuously for two cycles of the reference frequency in the high current phase region where the current command is high. It is characterized by that.

  According to the above configuration, by applying the synchronous PWM control to the generation of the inverter switching control signal, it is possible to stably control the rotating electrical machine using the low frequency carrier wave. By using a low-frequency carrier wave, switching loss of the inverter can be reduced. Then, based on the current command, the carrier frequency is switched to a high frequency obtained by multiplying the reference frequency by an integer, thereby dispersing the carrier frequency and suppressing electromagnetic noise caused by the low-frequency carrier. Furthermore, in the high current phase region corresponding to the same switching element, the reference frequency is not continuously switched to the high frequency, or in the high current phase region where the current command is high, the reference frequency is continuously increased to the high frequency for two cycles. By not switching, heat generation of the switching element can be suppressed while suppressing electromagnetic noise.

  Moreover, it is preferable that the carrier wave control unit switches the frequency of the carrier wave to a high frequency obtained by multiplying the reference frequency by an integer based on the number of synchronizations and the phase of the current command. According to this configuration, it is easy to prevent the carrier frequency from increasing in a place where the heat generation amount of the switching element is large, that is, in a high current phase region. On the other hand, when the amount of heat generated by the switching element is small, switching of carriers can be promoted to suppress electromagnetic noise.

  Moreover, it is preferable that the carrier wave control unit switches the frequency of the carrier wave to a high frequency obtained by multiplying the reference frequency by an integer based on the rotation speed and torque of the rotating electrical machine. According to this configuration, for example, the state in which the noise level is increased based on the rotational speed and torque of the rotating electrical machine is specified in advance, and the high noise level is set to a high frequency switching magnification to suppress noise, At a low noise level, the switching magnification can be set low to suppress the heat generation of the switching element.

  According to the control device for a rotating electrical machine according to the present invention, it is possible to achieve both higher levels of suppression of electromagnetic noise and suppression of heat generation by switching while maintaining good controllability.

It is a block diagram which shows the structure of the control apparatus of the rotary electric machine which is embodiment of this invention, and the rotary electric machine drive system which mounts it. It is a figure which shows the structure of an inverter. In the control apparatus which is embodiment of this invention, it is a figure which shows the relationship between the waveform of the voltage command of each phase, and a carrier. In the control apparatus which is embodiment of this invention, it is a figure which shows the relationship between the waveform of a W-phase current command, the waveform of a W-phase voltage command, and a carrier. It is a figure which shows the arrangement | positioning map which prescribed | regulated the switching pattern of a carrier frequency in the control apparatus which is embodiment of this invention. It is a figure which shows the magnification map which prescribes | regulates the relationship between the rotation speed of a rotary electric machine, the torque of a rotary electric machine, and the prescription | regulation magnification of a carrier frequency in the control apparatus which is embodiment of this invention. It is a flowchart which shows an example of control by the control apparatus which is embodiment of this invention. It is a figure for demonstrating the synchronization with the waveform of a voltage command, and a carrier. It is a figure for demonstrating the synchronization with the waveform of a voltage command, and a carrier.

  Hereinafter, embodiments of a control apparatus for a rotating electrical machine according to the present invention will be described in detail with reference to the drawings. In the embodiment, a motor drive system 10 applied to a hybrid vehicle (hereinafter, referred to as an HV vehicle) is described as an example of a control target, but the scope of application of the present invention is not limited to this. The HV vehicle includes, for example, two rotating electric machines. In FIG. 1, a configuration diagram related to control of a motor generator 11 (hereinafter simply referred to as a motor 11) that mainly functions as a traveling motor is illustrated, but the same configuration diagram also applies to a motor generator that mainly functions as a generator. Applicable.

  First, the configuration of the motor drive system 10 and the control device 20 will be described in detail with reference to FIG. Moreover, FIGS. 2-6 is referred suitably.

  FIG. 1 shows a schematic configuration of a motor drive system 10 equipped with a control device 20. As shown in FIG. 1, the motor drive system 10 includes a motor 11, a battery 12 that can supply power to the motor 11, an inverter 13 that is an AC / DC converter, and a converter 14 that boosts the DC voltage of the battery 12. And a control device 20 that controls the driving of the motor 11. The motor drive system 10 includes a current sensor 18, a rotation angle sensor 19, and the like as sensors that detect information necessary for controlling the motor 11 by the control device 20.

  The HV vehicle includes an engine (not shown) as a driving power source. In addition, the HV vehicle is integrated based on, for example, a power distribution mechanism that distributes power between the engine and the two rotating electric machines, an accelerator opening degree, a vehicle speed, a charge rate (SOC: State Of Charge) of the battery 12, and the like. HV control device for controlling the running function of the vehicle, a battery monitoring device for monitoring the SOC of the battery 12, various sensors (for example, accelerator position sensor) for detecting information necessary for vehicle drive control, etc. Yes.

  The motor 11 is, for example, a three-phase synchronous rotating electric machine including a rotor made of a permanent magnet and a stator including U-phase, V-phase, and W-phase stator coils. The motor 11 is rotationally driven by electric power supplied from the battery 12. Specifically, the direct current of the battery 12 is converted into a three-phase alternating current by the inverter 13 and supplied to the motor 11. For example, the output of the motor 11 is transmitted to the drive wheels via a power distribution mechanism or the like to which the rotating shaft is connected. Therefore, in the HV vehicle, traveling that assists the engine by the motor 11 or so-called EV traveling that uses only the motor 11 as a power source is possible. Further, the motor 11 functions as a generator during regenerative braking.

  The battery 12 is a power storage device that mainly supplies power to the motor 11. A secondary battery such as a nickel cadmium battery, a nickel metal hydride battery, or a lithium ion battery is applied to the battery 12. From the viewpoint of efficient use, prevention of deterioration, and the like, the battery 12 has a management range (for example, 20% to 80%) with a predetermined SOC as an upper and lower limit value, and a target SOC (for example, a charge / discharge standard) 60%) is set.

  FIG. 2 shows the configuration of the inverter 13. As shown in FIG. 2, the inverter 13 is provided in parallel between a power line and a ground line connected to the positive terminal and the negative terminal of the battery 12 via a converter 14, a relay (not shown), and the like. Inverter 13 includes a U-phase upper and lower arm 15, a V-phase upper and lower arm 16, and a W-phase upper and lower arm 17 corresponding to each phase of motor 11. Each phase upper and lower arm includes a plurality of switching elements. For example, the U phase upper and lower arms 15 are switching elements Q1 and Q2, the V phase upper and lower arms 16 are switching elements Q3 and Q4, and the W phase upper and lower arms 17 are Switching elements Q5 and Q6 are included, respectively. Antiparallel diodes D1 to D6 are connected to switching elements Q1 to Q6, respectively.

  As the switching element, a semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor), a power MOS (Metal Oxide Semiconductor) transistor, or a power bipolar transistor can be used. Switching elements Q1 to Q6 are turned on / off by switching control signals S1 to S6 output from control device 20.

For example, when the torque command value T ^* of the motor 11 is positive, the inverter 13 switches the switching elements Q1 to Q6 based on the switching control signals S1 to S6 to change the DC voltage of the battery 12 to an AC voltage. The drive is controlled so that a positive torque is output from the motor 11. On the other hand, during regenerative braking of the HV vehicle, the torque command value T ^* of the motor 11 is set negative. In this case, the inverter 13 converts the AC voltage generated by the motor into a DC voltage, and supplies the converted DC voltage to the converter 14. Converter 14 steps down the DC voltage and then supplies it to battery 12.

  The current sensor 18 is a sensor that detects a current flowing through the motor 11. Since the sum of instantaneous values of the currents Iu, Iv, and Iw of each phase is zero, the current sensor 18 detects the motor current for two phases (for example, the V-phase current Iv and the W-phase current Iw). What is necessary is just to arrange. The rotation angle sensor 19 is a sensor that detects the rotor rotation angle θ of the motor 11. The control device 20 can calculate the rotation speed of the motor 11 based on the rotor rotation angle θ.

The control device 20 is, for example, an electronic control unit (ECU) that controls the motor 11 in accordance with an output request from the HV control device, and includes a CPU, an input / output port, a memory, and the like. The control device 20 generates a switching control signal for controlling the switching operation of the inverter 13 according to the torque command value T ^* which is an output request from the HV control device, and controls the motor 11 using the inverter 13. In order to execute this control, the control device 20 includes a current command generation unit 21, a PI calculation unit 22, a first coordinate conversion unit 23, a PWM signal generation unit 24, a second coordinate conversion unit 25, and a rotation speed. A calculation unit 26 and a carrier control unit 27 are provided.

  As a control method by the control device 20, synchronous PWM control is applied. However, unlike the normal synchronous PWM control, a part of the carrier frequency is changed to a higher frequency based on the current command while maintaining the synchronization between the rotation speed of the motor 11 and the carrier. This point will be described in detail later.

In PWM control, for example, a sinusoidal voltage command corresponding to the torque command value T ^* is compared with a carrier that is a triangular wave, and 1 (ON) when the sine wave is larger than the triangular wave, and 0 ( OFF) is generated. The voltage command is supplied as a sine wave signal having a phase difference of 120 ° with respect to each phase of the motor 11. On the basis of the generated pulse signal, the switching elements Q1 to Q6 are turned on / off to apply a pulse width modulation voltage as a pseudo sine wave voltage to each phase.

  FIG. 3 shows the relationship between the voltage command waveform for each phase of the motor 11 and the carrier. As shown in FIG. 3, in the synchronous PWM control, the carrier frequency is controlled so as to be an integral multiple (at least twice or more) of the rotation frequency of the motor 11 in synchronization with the rotation speed (rotation frequency) of the motor 11. The This is executed by the function of the carrier control unit 27. The carrier control unit 27 changes a part of the reference frequency fc to a high frequency (hereinafter referred to as a multiplication frequency fh) that is an integral multiple of the reference frequency fc in order to suppress the electromagnetic noise by dispersing the carrier frequency.

  Here, the reference frequency fc is a carrier frequency set based on a predetermined number of synchronizations and the number of rotations (rotation frequency) of the motor 11. The number of synchronizations is determined in advance as the number of carriers included in one cycle (360 °) of the electrical angle of the motor 11. That is, the number of synchronizations is the number of carriers of the reference frequency fc included in one electrical angle cycle, and can be set to an arbitrary multiple of 3, for example. In the example shown in FIG. In other words, the reference frequency fc is set based on the number of rotations of the motor 11 so that the number of synchronizations is 6. Further, since the voltage command is also synchronized with the number of rotations of the motor 11, the synchronization number can be said to be the number of carriers of the reference frequency fc per cycle of the voltage command.

The current command generator 21 generates current commands Id ^* and Iq ^* based on the torque command value T ^* for the motor 11 and the rotation speed Nm of the motor 11 according to a table stored in advance. An example of the predetermined table is a TN control map showing the relationship between the rotation speed of the motor 11 and the output torque for each current value.

  The rotation speed Nm of the motor 11 is calculated based on the rotor rotation angle θ detected by the rotation angle sensor 19 by the rotation speed calculation unit 26. Further, in the second coordinate conversion unit 25, the d-axis is based on the V-phase current Iv and the W-phase current Iw detected by the current sensor 18 by coordinate conversion using the rotor rotation angle θ (3 phase → 2 phase). A current Id and a q-axis current Iq are calculated.

The PI calculation unit 22 has a function of generating a d-axis voltage command Vd ^* and a q-axis voltage command Vq ^* according to the control deviation. Specifically, the PI calculation unit 22 includes the d-axis current command Id ^* and the q-axis current command Iq ^* generated by the current command generation unit 21, the d-axis current Id calculated by the second coordinate conversion unit 25, and deviation between the q-axis current ^{Iq ΔId (ΔId = Id * -Id} ), ΔIq (ΔIq = Iq * -Iq) is input. Then, the PI calculation unit 22 performs a PI calculation (proportional integration calculation) with a predetermined gain for each of the d-axis current deviation ΔId and the q-axis current deviation ΔIq to obtain a control deviation, and a d-axis voltage corresponding to the control deviation A command Vd ^* and a q-axis voltage command Vq ^* are generated.

The first coordinate conversion unit 23 performs coordinate conversion (2 phase → 3 phase) using the rotor rotation angle θ of the motor 11, and the d-axis voltage command Vd ^* and the q-axis voltage command created by the PI calculation unit 22. It has a function of converting Vq ^* into voltage commands Vu ^* , Vv ^* , Vw ^* corresponding to each phase of the motor 11.

As described above, the PWM signal generation unit 24, for example, based on the comparison between the voltage commands Vu ^* , Vv ^* , Vw ^{* of} each phase supplied from the first coordinate conversion unit 23 and the carrier, for example, the inverter 13 Switching control signals S1 to S6 for turning on / off the six switching elements Q1 to Q6 are generated. Then, the inverter 13 is switched according to the switching control signals S1 to S6, whereby an AC voltage for outputting torque according to the torque command value T ^* is applied to the motor 11. Note that the PWM signal generation unit 24 generates a carrier according to the frequency (reference frequency fc or multiplication frequency fh) set by the carrier control unit 27.

  The carrier control unit 27 has a function of controlling the frequency of the carrier used in the PWM signal generation unit 24. The carrier control unit 27 includes a reference frequency setting unit 28 that sets the carrier reference frequency fc, and a frequency switching unit 29 that switches the carrier frequency to a multiplication frequency fh that is higher than the reference frequency fc based on the current command. Have.

  The reference frequency setting means 28 determines the reference frequency fc of the carrier based on the number of synchronizations determined in advance as the number of carriers per carrier of the electrical angle of the motor 11 (carrier of the reference frequency fc) and the number of rotations of the motor 11. Has the function of setting. For example, the reference frequency setting unit 28 acquires the rotation speed Nm of the motor 11 from the rotation speed calculation unit 26 and calculates the reference frequency fc using a predetermined synchronization number. That is, the reference frequency setting means 28 changes and sets the reference frequency fc according to the rotation speed of the motor 11. The number of the aircraft may vary depending on the state of the motor 11 and the like as long as it is determined at the time of setting the reference frequency fc.

  The frequency switching unit 29 has a function of switching the carrier frequency to a multiplication frequency fh obtained by multiplying the reference frequency fc by an integer based on the current command. That is, the frequency switching unit 29 disperses the carrier frequency and mixes the reference frequency fc and the multiplication frequency fh that is an integral multiple of the reference frequency fc. As a result, noise caused by the carrier having the reference frequency fc having a low frequency is dispersed and the noise level is lowered.

  The frequency switching means 29 determines the frequency switching timing and the frequency specified magnification Z from the viewpoint of achieving both high levels of suppression of electromagnetic noise and suppression of heat generation by switching of the inverter 13. Here, the specified magnification Z means fh / fc, and corresponds to an “integer” when switching to the multiplication frequency fh obtained by multiplying the reference frequency fc by an integer. The frequency switching unit 29 preferably switches the frequency in units of one cycle of the reference frequency fc based on the number of synchronizations and the phase of the current command (hereinafter simply referred to as current phase). Moreover, it is preferable that the frequency switching unit 29 changes the specified magnification Z based on the rotation speed (rotation frequency) of the motor 11 and the torque of the motor 11.

  FIG. 4 shows the relationship between the waveforms of the current command and voltage command for the W phase and the carrier. In the example illustrated in FIG. 4, the reference frequency fc and the multiplication frequency fh are alternately repeated every other period of the reference frequency fc in a certain electrical angle cycle (the first electrical angle cycle). That is, the frequency switching unit 29 switches the reference frequency fc to the multiplication frequency fh at a rate of once every two periods of the reference frequency fc in the first electrical angle period. On the other hand, in the second electrical angle cycle following the first electrical angle cycle, for example, switching from the reference frequency fc to the multiplication frequency fh is not performed. The specified magnification Z is preferably 2 or 3 times, for example.

  In order to suppress heat generation due to switching of the inverter 13, the frequency switching unit 29 continuously switches to the multiplication frequency fh in the high current phase region Rh corresponding to the same switching element in the high current phase region Rh where the current command becomes high. It is preferred not to. That is, there are two switching elements of the inverter 13 corresponding to each phase of the motor 11, but carriers are supplied in the high current phase region Rh (Q 6) corresponding to one of the two switching elements (for example, the switching element Q 6). When switching to the multiplication frequency fh, switching from the reference frequency fc to the multiplication frequency fh is not performed in the next high current phase region Rh (Q6) corresponding to the switching element Q6.

  In other words, when the upper arm of the same phase is switched from the reference frequency fc to the multiplication frequency fh (hereinafter also simply referred to as higher frequency), the higher frequency is increased again in the high current phase region Rh. In the meantime, it is preferable to sandwich at least one high current phase region Rh where high frequency is not implemented. On the other hand, after increasing the frequency in the high current phase region Rh (Q6), the frequency may be increased in the subsequent high current phase region Rh (Q5).

  In addition, in order to suppress heat generation due to switching of the inverter 13, the frequency switching unit 29 is preferably not switched to the multiplication frequency fh continuously for two cycles of the reference frequency fc in the high current phase region Rh. For example, by increasing the frequency every other period of the reference frequency fc, it is possible to prevent the reference frequency fc from switching to the multiplication frequency fh in the high current phase region Rh continuously for two periods of the reference frequency fc. . On the other hand, in the low current phase region where the current command is low, the carrier frequency may be switched to the multiplication frequency fh continuously for two cycles of the reference frequency fc.

  The high current phase region Rh that should limit the increase in the carrier frequency is a region that is 50% or more of the current amount when the current amount at the amplitude peak of the current command is 100, or 70% or more. Or an area that is 80% or more.

  FIG. 5 shows an arrangement map (for one electrical angle period) defining the carrier frequency switching pattern. The arrangement map shown in FIG. 5 is a two-dimensional map that defines the target period of the reference frequency fc for increasing the frequency by using the number of synchronizations and the current phase as arguments. In the arrangement map shown in FIG. 5, the target period of the reference frequency fc for performing higher frequency is stored as 1, and the target period of the reference frequency fc for which higher frequency is not performed is stored as 0. Three non-implementation periods are sandwiched between two target periods to be implemented. For example, the arrangement map is such that 1 (execution) does not continue in the adjacent high current phase region Rh of the same switching element, and 1 (continuous) for two periods of the reference frequency fc in the high current phase region Rh. It is preferable to define 1 (execution) and 0 (non-execution) so as not to be (execution).

  The frequency switching unit 29 can switch the carrier frequency by using an arrangement map as illustrated in FIG. For example, the frequency switching unit 29 reads out the synchronization number from the memory of the control device 20, obtains the rotor rotation angle θ detected by the rotation angle sensor 19, derives the current phase, and based on the synchronization number and the current phase. The target period of the reference frequency fc for switching the carrier frequency is specified from the arrangement map.

  FIG. 6 shows a magnification map that defines the relationship among the rotational speed of the motor 11, the torque of the motor 11, and the prescribed magnification Z. The magnification map shown in FIG. 6 is a two-dimensional map that defines a specified magnification Z of 1 ×, 2 ×, and 3 × using the rotation speed of the motor 11 and the torque of the motor 11 as arguments. Here, 1 × means that the reference frequency fc is maintained. In this magnification map, for example, in the range where the torque of the motor 11 is 30 Nm or less, the carrier frequency is increased regardless of the rotation speed of the motor 11. Do not implement.

  In the magnification map shown in FIG. 6, the specified magnification Z is set higher (Z = 3) as the torque of the motor 11 is larger (for example, 50 Nm) and the rotational speed is lower (for example, 1000 rpm). On the other hand, even if the torque is large (for example, 40 Nm), the specified magnification Z is set low (Z = 1) in the range where the rotational speed is large (for example, 4000 rpm or more).

  As shown in FIGS. 3 to 6, the carrier frequency switching pattern and the specified magnification Z can be changed as appropriate within a range in which the heat generation of the inverter 13 does not cause a problem. For example, in the example shown in FIGS. 4 and 5, a part of the reference frequency fc is increased based on the current phase of the W phase, but based on the current phase of the U phase or the V phase, or The frequency may be increased based on the current phases of a plurality of phases. 3 and 4, the reference frequency fc and the multiplication frequency fh are alternately repeated every other period of the reference frequency fc. For example, in the first electrical angle period, the reference frequency fc May be switched to the multiplication frequency fh, and a switching pattern in which high frequency is not implemented in the second electrical angular period following the first electrical angular period, or in several electrical angular periods.

  Next, an example of carrier frequency control by the control device 20 will be described with reference to FIG. 8 and 9 will be referred to as appropriate. In the following description, it is assumed that carrier synchronization is executed based on the U-phase voltage command (U-phase voltage) and carrier frequency switching is executed based on the W-phase current phase.

  As shown in FIG. 7, the rotation speed of the motor 11 and the carrier are synchronized, and the reference frequency fc is set based on the rotation number Nm (rotation frequency) of the motor 11 and the synchronization number (S10 to S13). The procedures of S10 to S13 are executed by the function of the reference frequency setting means 28. First, the rotor rotation angle θ of the motor 11 is acquired from the rotation angle sensor 19, and the current electrical angle is derived (S10). Subsequently, a relative angle from the current electrical angle to the zero cross position where the U-phase voltage is 0 is derived (S11). Then, the remaining time when the current reference frequency fc is repeated is calculated (S12). Then, the reference frequency fc is determined by recalculating the carrier frequency (the fraction of the carrier) from the remaining time (S13).

  As shown in FIG. 8, when the zero cross position is reached from the present time (assuming that the rotation speed of the motor 11 does not change during that time), if the zero cross position matches the carrier cycle T, the correction amount is 0. That is, the reference frequency fc is not changed. On the other hand, as shown in FIG. 9, when the vehicle advances from the current time to the zero cross position (assuming that the rotation speed of the motor 11 does not change during that time), if the zero cross position does not match the carrier cycle, the carrier frequency Correction is required. For example, when the correction amount is 1/4, the carrier period T is (1-1 / 4) T and the frequency is an inverse number. After the correction, the reference frequency fc is set based on the rotation speed Nm of the motor 11 and the synchronization number.

Subsequently, based on the rotation speed Nm of the motor 11 and the torque command value T ^* for the motor 11, the specified magnification Z is determined from the magnification map (S14). In the range where the torque command value T ^* is small, the specified magnification Z in the magnification map may be set to 1 so that the carrier frequency is not switched.

  Subsequently, it is confirmed whether or not the current phase is to be switched carrier frequency from the arrangement map defining the carrier frequency switching pattern (S15), for example, if the arrangement map is 1 (implementation), The multiplication frequency fh is determined by multiplying the reference frequency fc by the specified magnification Z (S16). That is, for the implementation target period of the reference frequency fc, the carrier frequency is set to the multiplication frequency fh. On the other hand, when the arrangement map is 0 (not implemented), the reference frequency fc is not switched. That is, an increase in the reference frequency fc is prohibited. The procedures of S14 to S16 are executed by the function of the frequency switching means 29.

The procedure of S15 proceeds as follows, for example. First, the d-phase current command Id ^* and the q-axis current command Iq ^* generated by the current command generation unit 21 and the electrical angle from the rotor rotation angle θ are identified and arranged, for example, as a W-phase current phase. Use the map to determine whether to increase the frequency.

  The carrier frequency set by the carrier control unit 27 is transmitted to, for example, the PWM signal generation unit 24, and the PWM signal generation unit 24 outputs a carrier according to the carrier frequency.

  As described above, the control device 20 switches the carrier frequency to the multiplication frequency fh that is an integral multiple of the reference frequency fc based on the current command, while continuously multiplying the multiplication frequency in the high current phase region Rh of the same switching element. Do not switch to fh. Further, in the high current phase region Rh, the multiplication frequency fh is not switched continuously for two cycles of the reference frequency fc. Thereby, while suppressing the electromagnetic noise by dispersing the reference frequency fc having a low frequency, in the high current phase region Rh where the amount of heat generated by the switching is large, the frequency increase can be significantly limited to suppress the heat generated by the switching. . That is, according to the control device 20, it is possible to achieve both higher levels of suppression of electromagnetic noise and suppression of heat generation by switching while maintaining good controllability.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle (HV vehicle), 11 Motor generator (motor), 12 Battery, 13 Inverter, 14 Converter, 15 U-phase upper / lower arm, 16 V-phase upper / lower arm, 17 W-phase upper / lower arm, 18 Current sensor, 19 Rotation angle sensor , 20 control device, 21 current command generation unit, 22 PI calculation unit, 23 first coordinate conversion unit, 24 PWM signal generation unit, 25 second coordinate conversion unit, 26 rotation speed calculation unit, 27 carrier control unit, 28 reference frequency Setting means, 29 Frequency switching means.

Claims (4)

In a control device for a rotating electrical machine that controls a voltage applied to the rotating electrical machine using an inverter including a plurality of switching elements,
Based on the comparison between the voltage command and the carrier wave, a signal generation unit that generates a switching control signal of the switching element,
A carrier wave control unit that sets a reference frequency of the carrier wave based on a predetermined number of synchronizations and the rotation speed of the rotating electrical machine;
With
The carrier wave control unit
Based on the current command, the frequency of the carrier wave is switched to a high frequency that is an integer multiple of the reference frequency, while in the high current phase region where the current command is high, the high current phase region corresponding to the same switching element is continuously high. A control device for a rotating electrical machine characterized by not switching to a frequency. In a control device for a rotating electrical machine that controls a voltage applied to the rotating electrical machine using an inverter including a plurality of switching elements,
Based on the comparison between the voltage command and the carrier wave, a signal generation unit that generates a switching control signal of the switching element,
A carrier wave control unit that sets a reference frequency of the carrier wave based on a predetermined number of synchronizations and the rotation speed of the rotating electrical machine;
With
The carrier wave control unit
Based on the current command, the frequency of the carrier wave is switched to a high frequency that is an integer multiple of the reference frequency in one cycle unit of the reference frequency. A control device for a rotating electrical machine characterized by not switching to a high frequency. In the control apparatus for the rotating electrical machine according to claim 1 or 2,
The carrier control unit switches the frequency of the carrier to a high frequency obtained by multiplying the reference frequency by an integer based on the number of synchronizations and the phase of the current command. In the control apparatus of the rotary electric machine according to any one of claims 1 to 3,
The carrier control unit switches the frequency of the carrier to a high frequency obtained by multiplying the reference frequency by an integer based on the rotation speed and torque of the rotating electric machine.

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