JPWO2017208652A1 - Motor controller - Google Patents

Abstract

Provided is a motor control device capable of reducing high frequency noise associated with DC bus current detection without changing the switching frequency. The motor control device 3 detects a three-phase current flowing in the three-phase motor based on the power converter 14, the three-phase motor 2 driven by the power converter, and the DC bus current, and detects the detected three-phase current And control means 13 for generating a phase voltage command value and controlling the power converter using the phase voltage command value, wherein the control means detects the d-c bus current when the d-axis voltage is detected. The phase voltage command value is corrected based on the above to shift the phase of the phase voltage pulse.

Description

  The present invention relates to a motor control device that detects a DC bus current to obtain AC current information.

  Small-sized, high-efficiency three-phase motors are widely used in various fields such as industry, home appliances and automobiles. The three-phase motor requires a current detector for detecting a three-phase current supplied to the inside of the stator. As a current detector, generally, a phase current detector that detects a three-phase current of a three-phase motor is common. On the other hand, in an automotive accessory system such as a motor control brake system, a motor power steering, a motor oil pump, etc., as a current detection means, the DC bus current flowing through the DC resistance provided for short circuit protection A DC bus current detection method is used in which a DC bus current value is sampled at a point of time at which a difference in switching timing occurs, and a three-phase current is reproduced. By adopting this current detection method, it is possible to omit three phase current detectors, which are normally provided, and therefore the cost of the motor control device can be reduced.

  In the DC bus current detection method, as the output voltage decreases, the difference in switching timing between the phases decreases, so the accuracy of current sampling decreases. That is, in the present system, the lower the output voltage, the more difficult the current detection.

  On the other hand, the technology described in Patent Document 1 is known. In the present technology, one cycle of the triangular wave carrier signal that generates the PWM signal is divided into a first half period and a second half period, the correction voltage value is added to the AC output voltage command value in the first half period, and the output voltage command value It enlarges itself to detect DC bus current. Further, in the second half period, the correction voltage value added in the first half period is subtracted so that the average output voltage does not fluctuate. As described above, in the technology described in Patent Document 1, the difference in switching timing is increased by increasing the difference in voltage command value between the phases by addition and subtraction of the correction voltage value. That is, in the present technology, the voltage command value is corrected so as to shift the phase of the phase voltage pulse.

  According to the technology described in Patent Document 1, although current can be reliably detected by the DC bus current detection method, with the correction of the voltage command value, that is, with the phase shift of the phase voltage pulse, the high frequency current according to the switching frequency is Because it is generated, high frequency noise is generated. In particular, when the output of the three-phase motor is small, the noise can be heard relatively loud to the motor operation noise.

  The technique of patent document 2 is known with respect to the problem of such a noise. In the present technology, when the AC output voltage of the power converter is low, the switching frequency of the power converter is increased to be out of the audible range, and when the output voltage of the power converter is high, the switching frequency of the power converter is To lower the heat generation of the power converter.

JP 2001-327173 A JP, 2014-168332, A

  In the technology described in Patent Document 2, the power loss of the power converter increases to increase the switching frequency in a region where the output voltage of the power converter is low, and the semiconductor element used for the power converter is broken due to heat generation. There is a risk of

  Therefore, the present invention provides a motor control device capable of reducing high frequency noise associated with DC bus current detection without changing the switching frequency.

  In order to solve the above problems, a motor control device according to the present invention detects a three-phase current flowing in a three-phase motor based on a power converter, a three-phase motor driven by the power converter, and a DC bus current. And control means for creating a phase voltage command value using the detected three-phase current and controlling the power converter using the phase voltage command value, the control means comprising: At the time of detection, the phase voltage command value is corrected based on the d-axis voltage to shift the phase of the phase voltage pulse.

  According to the present invention, the current detection width at the time of DC bus current detection is secured, current detection accuracy is improved, and motor noise generated with phase shift of phase voltage pulse for securing current detection width is reduced. can do.

  Problems, configurations, and effects other than those described above will be clarified by the description of the embodiments below.

It is a block diagram showing composition of a motor control device which is a 1st embodiment of the present invention. It is a functional block diagram which shows the structure of the control means in FIG. It is a waveform example of the pulse width modulation signal which shows operation | movement in a pulse width adjustment part. It is a vector diagram which shows the pulse width adjustment means in a comparative example. It is a wave form diagram which shows the voltage command value and PWM carrier wave in a comparative example. It is a vector diagram which shows the pulse width adjustment means in 1st Embodiment. It is a wave form diagram showing a voltage command value and a PWM carrier wave in a 1st embodiment. FIG. 2 shows a configuration of a pulse width adjustment unit in FIG. It is a vector diagram which shows the pulse width adjustment means in the 2nd Embodiment of this invention. It is a wave form diagram showing a voltage command value and a PWM carrier wave in a 2nd embodiment. It is a block diagram which shows the structure of the motor control apparatus of 2nd Embodiment. It is a vector diagram which shows the pulse width adjustment means in the 3rd Embodiment of this invention. The structure of the electrically-controlled type | mold brake which is the 4th Embodiment of this invention is shown. The structure of the electrically-driven power steering which is the 5th Embodiment of this invention is shown. The structure of the pump drive system which is the 6th Embodiment of this invention is shown.

  Hereinafter, embodiments of the present invention will be described using the drawings.

  In the drawings, those with the same reference numerals indicate components having the same configuration or similar functions.

First Embodiment
A first embodiment of the present invention will be described using FIGS. 1 to 3.

  FIG. 1 is a block diagram showing a configuration of a motor control device according to a first embodiment of the present invention.

  As shown in FIG. 1, the motor control device 3 includes a three-phase motor 2 and a controller 1 that supplies three-phase AC power to the three-phase motor 2 to drive the three-phase motor 2. The controller 1 has a DC power supply 11 and a power converter 14 that converts DC power of the DC power supply 11 into three-phase AC power and outputs the power to the three-phase motor 2. Here, in the present embodiment, a permanent magnet synchronous motor is applied as the three-phase motor 2.

  The power converter 14 constitutes a three-phase inverter circuit composed of six semiconductor switching elements (MOSFETs in FIG. 1). DC power is converted into three-phase AC power by on / off control of these six semiconductor switching elements by pulse width modulation signals Sup, Svp, Swp, Sun, Svn, Swn output from the control means 13. Ru. The control means 13 detects a three-phase alternating current output from the power converter 14 based on the direct current bus current detector 12, for example, the direct current bus current Idc detected by the shunt resistor. Based on the detected three-phase alternating current, the control means 13 creates pulse width modulation signals Sup, Svp, Swp, Sun, Svn, Swn.

  FIG. 2 is a functional block diagram showing a configuration of control means 13 in FIG.

  As shown in FIG. 2, the control unit 13 includes a three-phase current reproduction unit 131, a dq axis current conversion unit 132, a voltage command calculation unit 133, a coordinate conversion unit 134, a pulse width adjustment unit 135, and a drive signal generation unit 136. Be done. In the present embodiment, a so-called vector control technique is applied.

  Three-phase current reproduction unit 131 generates three-phase current detection value Iuc using direct current bus current Idc detected by current detector 12 (FIG. 1) using pulse width modulation signals Sup, Svp, Swp, Sun, Svn, and Swn. , Ivc, Iwc. As described later, in the present embodiment, the pulse width modulation signal is phase shifted in order to reliably detect the three-phase current. In addition, as a means to obtain a three-phase current detection value, a known technique (for example, refer to the above-mentioned patent document 1) is applied except for a phase shift means of a pulse width modulation signal.

  The dq-axis current conversion unit 132 uses the three-phase currents Iuc, Ivc, and Iwc, which are outputs of the three-phase current reproduction unit 131, using the rotor phase θdc of the three-phase motor 2 (FIG. 1). The current detection values Idc and Iqc (DC amount) are converted, and these detection values are output. The rotor phase θdc is detected by a position detector such as a resolver, or estimated from the three-phase current or three-phase voltage of the three-phase motor 2 without using a position detector, that is, using a known sensorless technique. Do. Alternatively, the rotor phase θdc of the three-phase motor 2 may be estimated by applying a known technique of estimating the rotor phase based on the neutral point potential of the three-phase motor.

  Voltage command calculation unit 133 calculates the difference between d-axis current command value Id * and d-axis current detection value Idc output by dq-axis current conversion unit 132, q-axis current command value Iq *, and dq-axis current conversion unit The d-axis voltage command value Vd * and the q-axis voltage command value Vq * are generated such that these differences approach zero, according to the difference from the q-axis current detection value Iqc output by 132. In voltage command calculation unit 133, for example, a d-axis voltage command value that brings the d-axis current difference closer to zero by proportional-integral (PI) control and a q-axis voltage command value that brings the q-axis current difference closer to zero. Is created. Note that the d-axis current command value Id * and the q-axis current command value Iq * are current command calculation units (not shown), for example, a speed control unit or torque control that creates a current command to obtain a desired motor speed or motor torque. Created by the department.

  The coordinate conversion unit 134 uses the rotor phase θdc of the three-phase motor 2 to output the d-axis voltage command value Vd and the q-axis voltage command value Vq output by the voltage command calculation unit 133 as the U-phase voltage command value Vu ′. V-phase voltage command value Vv 'and W-phase voltage command value Vw' are converted, and these Vu ', Vv' and Vw 'are output.

  The pulse width adjustment unit 135 inputs the phase voltage command values Vu ', Vv' and Vw ', and corrects Vu', Vv 'and Vw' so that the current detection width can be secured by pulse width adjustment means described later. The corrected U-phase voltage command value Vu, the corrected V-phase voltage command value Vv, and the corrected W-phase voltage command value Vw are output. When the pulse width modulation signal is generated based on phase voltage command values Vu ', Vv' and Vw ', pulse width adjustment unit 135 reduces the current detection width and DC bus current such that detection of DC bus current becomes difficult At the detection timing, phase voltage command values Vu ′, Vv ′ and Vw ′ are corrected in order to perform phase shift based on the d-axis voltage as described later. Here, based on the rotor phase θdc, the pulse width adjustment unit 135 determines the magnitude relationship between the DC bus current detection time point and the d-axis voltage of the phase voltage command values Vu ′, Vv ′ and Vw ′ at that time point. The phase voltage command value in which the d-axis voltage is maximum and the phase voltage command value in which the d-axis voltage is minimum are corrected. The phase voltage command value in which the d-axis voltage is at an intermediate level is not substantially corrected.

  The drive signal generation unit 136 generates six pulse width modulation signals Sup, Svp, Swp, Sun, Svn, and Swn based on the corrected phase voltage command values Vu, Vv and Vw output from the pulse width adjustment unit 135. Do. Here, so-called PWM (Pulse Width Modulation) control technology is applied, in which phase voltage command values Vu, Vv and Vw (modulated wave signal) and a carrier wave signal (for example, triangular wave signal) are compared to create a pulse width modulated signal. Be done.

  FIG. 3 is a waveform example of a pulse width modulation signal showing an operation of pulse width adjustment in the pulse width adjustment unit 135.

  As shown in FIG. 3, in the case of the pulse width modulation signals Sup ', Svp' and Swp 'of the upper arms of each phase obtained by PWM control using the phase voltage command values Vu', Vv 'and Vw' before correction, Since each phase of the upper arm of the power converter 14 (FIG. 1) switches (ON) simultaneously, the DC bus current Idc becomes 0, and it is difficult to detect a three-phase current from the DC bus current.

  On the other hand, the pulse width modulation signal Sup obtained by PWM control using the corrected U-phase voltage command value Vu is the pulse modulation of the U-phase upper arm obtained using the U-phase voltage command value Vu 'before correction. The phase of the signal Sup 'is shifted to the right in the figure, that is, in the delay direction. The pulse width modulation signal Swp obtained by PWM control using the W phase voltage command value Vw after correction is a pulse modulation signal Swp of the W phase upper arm obtained using the W phase voltage command value Vw 'before correction. The phase is shifted to the left in the figure, that is, in the lead direction with respect to '. The phase of pulse width modulation signal Svp obtained by PWM control using corrected V-phase voltage command value Vv is pulse modulation of the V-phase upper arm obtained using V-phase voltage command value Vv 'before correction. It is the same as the phase of the signal Svp 'and is not shifted. Since the DC bus current Idc flows as shown in FIG. 3 by such phase shift, it is possible to detect a three-phase current from the DC bus current.

  The pulse width adjustment unit 135 in this embodiment is a voltage in the d-axis direction that has little or no influence on the torque of the three-phase motor with a predetermined amount of correction voltage pulse given to the phase voltage command value to shift the phase. (D-axis voltage) As a result, the three-phase current can be reliably detected based on the DC bus current, and high frequency noise associated with the phase shift can be reduced. Such a pulse width adjustment unit 135 will be described below with reference to FIGS. Note that, first, pulse width adjustment of the comparative example will be described, and next, pulse width adjustment of the present embodiment will be described.

  FIG. 4 is a vector diagram showing the pulse width adjusting means in the comparative example. In FIG. 4, directions of three-phase (U-phase, V-phase, W-phase) phase voltage vectors U, V, W, an output voltage vector, a correction voltage vector (broken line arrow) and a d axis The magnetic flux axes of the magnets (S, N) of the motor rotor and the q axis (torque axis) forming an angle of 90 ° with the d axis are shown.

  As shown in FIG. 4, the correction voltage vector (broken line arrow) in the comparative example has a d-axis component and a q-axis component. Therefore, the correction of the phase voltage command value affects the torque of the three-phase motor 2 and noise is generated.

  FIG. 5 is a waveform diagram showing phase voltage command values before and after correction and a PWM carrier wave (triangular wave) in the comparative example. In FIG. 5, U-phase voltage command value Vu ', V-phase voltage command value Vv' and W-phase voltage command value Vw 'before correction, U-phase voltage command value Vu after correction, V-phase voltage command value Vv And W phase voltage command value Vw.

  As shown in FIG. 5, in the comparative example, W phase voltage command value Vw '(maximum phase) having the largest magnitude among three phases and U phase voltage command value Vu' (minimum The correction phase voltage of a predetermined amount is added to or subtracted from each phase to obtain a U-phase voltage command value Vu and a W-phase voltage command value Vw after pulse width correction. The V-phase voltage command value Vv '(intermediate phase) having an intermediate magnitude is used as the V-phase voltage command value Vv after pulse width correction without correction. This correction enlarges the magnitude of the voltage difference between the maximum phase (W phase) and the middle phase (V phase) and the magnitude of the voltage difference between the middle phase (V phase) and the minimum phase (U phase) . The maximum phase, the medium phase and the minimum phase are respectively W phase, V phase and U phase before and after correction.

  According to the above correction, although not shown, a W-phase (maximum phase) voltage pulse obtained by comparing the PWM carrier wave (triangular wave) with the W-phase voltage command value Vw and the V-phase voltage command value Vv The difference in switching timing of V-phase (intermediate phase) voltage pulses can be obtained by comparing the PWM carrier (triangular wave) with the W-phase (maximum phase) voltage command Vw 'and the V-phase (interphase) voltage command Vv' The phase of the W-phase voltage pulse after voltage correction is shifted so as to be larger than the difference between the switching timings of the W-phase voltage pulse and the V-phase (interphase) voltage pulse. Similarly, the phase of the U-phase (minimum phase) voltage pulse is also shifted. Thereby, the current detection width is secured, and the sampling accuracy of the DC bus current is improved, so that the three-phase current can be reliably detected based on the DC bus current. However, as described above, in the comparative example, since the correction voltage command has the q-axis component, motor noise is generated.

  FIG. 6 is a vector diagram showing the pulse width adjusting means in the present embodiment. Similar to FIG. 4, the directions of three-phase voltage vectors U, V, W, output voltage vectors, correction voltage vectors (solid arrows), and d-axis and q-axis in the rotational coordinate system are shown.

  As shown in FIG. 6, the correction voltage vector (solid line arrow) in the present embodiment has only the d-axis component among the d-axis component and the q-axis component. Here, as the motor output is smaller and the rotation of the three-phase motor is slower, that is, when the output voltage of the power converter 14 (FIG. 1) or the motor speed is lower than rated and is near zero, There is little influence on it. Therefore, by correcting the d-axis voltage, it is possible to reduce motor noise that becomes more noticeable as the rotation of the motor is slower.

  FIG. 7 is a waveform diagram showing phase voltage command values before and after pulse width adjustment and a PWM carrier wave (triangular wave) in the present embodiment. 7, similarly to FIG. 5, U-phase voltage command value Vu 'before correction, V-phase voltage command value Vv' and W-phase voltage command value Vw ', and U-phase voltage command value Vu after correction, V phase voltage command value Vv and W phase voltage command value Vw are shown.

  As shown in FIG. 7, of the three phases, the U-phase voltage command value Vu 'having the largest magnitude of the d-axis direction component and the V-phase voltage command value Vv' having the smallest magnitude of the d-axis directional component A corrected d-axis voltage of a predetermined amount is respectively added or subtracted to obtain a corrected U-phase voltage command value Vu and a V-phase voltage command value Vv. Note that the W-phase voltage command value Vw 'whose d-axis direction component has an intermediate magnitude is used as the W-phase voltage command value Vw after the correction without correction.

  In FIG. 7, the maximum phase, medium phase and minimum phase before correction are W phase, U phase and V phase respectively, but the maximum phase, middle phase and minimum phase after correction are U phase, W phase and It is V phase. Thus, unlike the comparative example, the maximum phase, the intermediate phase and the minimum phase do not necessarily coincide before and after correction. However, the magnitude of the voltage difference between the maximum phase (before correction: W phase, after correction: U phase) and the middle phase (before correction: U phase, after correction: W phase), and the middle phase (before correction: U phase) The magnitude of the voltage difference between after correction: W phase) and the minimum phase (before correction: V phase, after correction: V phase) is expanded as in the comparative example.

  According to the above correction, although not shown, the PWM carrier wave (triangular wave), the U phase voltage command value Vu of the maximum phase after correction, and the W phase voltage command value Vw of the middle phase after correction as in the comparative example Of the switching timings of the U-phase voltage pulse and the W-phase voltage pulse obtained by comparing the PWM carrier (triangular wave) with the phase voltage command value Vw 'of the maximum phase and the U phase voltage command value Vu' of the intermediate phase. The phase of the U-phase voltage pulse after voltage correction is shifted so as to be larger than the difference between the switching timings of the W-phase voltage pulse and the U-phase voltage pulse obtained by comparing. Similarly, the phase of the V-phase voltage pulse is also shifted. Thus, the current detection width of the DC bus current is secured, and the sampling accuracy of the DC bus current is improved, so that the three-phase current can be reliably detected based on the DC bus current. Furthermore, as described above, in the present embodiment, since the correction voltage is only the d-axis component, motor noise can be reduced.

  FIG. 8 shows the configuration of the pulse width adjustment unit 135 in FIG. 1 in which the above-described pulse width adjustment means is used. The d-axis direction correction phase voltage determination unit 1352 determines that the phase with the largest d-axis voltage and the d-axis voltage are minimum among the U-phase, V-phase, and W-phase at the time of DC bus current detection based on the rotor phase θdc. Select the phase of The pulse shift phase adjustment unit 1351 receives the voltage command values Vu ′, Vv ′ and Vw ′ generated by the coordinate conversion unit 134 (FIG. 2), and among these phase voltage command values, the d-axis direction correction phase voltage The phase voltage command values of the phases with the largest and smallest d-axis voltages selected by determination unit 1352 are corrected and output as corrected voltage command values Vu, Vv and Vw including the voltage command values not corrected. . Here, the correction voltage is set in the pulse shift adjustment unit 1351 by the correction d-axis voltage setting unit 1353. The correction d-axis voltage setting unit 1353 stores in advance the correction voltage of the d-axis voltage with respect to each phase voltage command value of the phase having the largest and the smallest phase of the d-axis voltage. Set the correction amount.

  The correction d-axis voltage setting unit 1353 may create the correction d-axis voltage according to the magnitudes of the phase voltage command values Vu ', Vv' and Vw 'before correction and the voltage difference between the phases. Thus, when the current detection width can be secured without correcting Vu ', Vv' and Vw ', the correction amount can be set to zero.

  As described above, according to the present embodiment, the current detection width is secured in the DC bus current detection method, the current detection accuracy is improved, and the generation occurs along with the phase shift of the phase voltage pulse for securing the current detection width. Motor noise can be reduced.

  The timing for correcting the phase voltage command value, that is, the sampling timing for detecting the DC bus current, and the magnitude of the correction voltage are such that the average value of the phase voltage command value becomes substantially equal before and after correction. It is set appropriately.

  Further, as described above, the smaller the motor output and the lower the motor rotation, the smaller the influence of the d-axis voltage on the torque is. Therefore, according to the present embodiment, the correction voltage in the q-axis direction is minimized if the q-axis current is near zero, not only when the output voltage is zero but also when the output voltage is greater than zero. Therefore, motor noise can be reduced.

Second Embodiment
Next, a motor control apparatus according to a second embodiment of the present invention will be described. The device configuration of this embodiment is the same as that of the first embodiment (FIGS. 1 and 2) described above.

  FIG. 9 is a vector diagram showing pulse width adjusting means in the second embodiment. Similar to FIG. 6, the directions of three-phase voltage vectors U, V and W, output voltage vectors, correction voltage vectors (solid arrows), and d-axis and q-axis in the rotational coordinate system are shown. FIG. 10 is a waveform diagram showing voltage command values before and after correction and a PWM carrier wave (triangular wave) in the present embodiment. In FIG. 10, as in FIG. 7, the U-phase voltage command value Vu 'before correction, the V-phase voltage command value Vv' and the W-phase voltage command value Vw ', and the U-phase voltage command value Vu after correction, V phase voltage command value Vv and W phase voltage command value Vw are shown.

  As shown in FIGS. 9 and 10, in this embodiment, unlike the first embodiment described above, of the U, V and W phases, only one of the phase with the largest d axis voltage and the smallest phase is used. Then, the phase voltage command value is corrected, and the direction of the correction voltage is taken as the d-axis direction. In the first embodiment (FIG. 7), the phase voltage command values of the U and V phases are corrected, whereas in the second embodiment, only the U phase is used as shown in FIGS. The phase voltage command value is corrected for.

  In the second embodiment, the d-axis direction correction phase voltage determination unit (reference numeral 1352 in FIG. 8) as described above selects only one of the maximum phase and the minimum phase of the d-axis voltage. Configured For example, the d-axis direction correction phase voltage determination unit 1352 selects the phase having the largest voltage difference from the intermediate phase of the d-axis voltage among the phases having the largest d-axis voltage and the smallest phase.

  FIG. 11 is a block diagram showing the configuration of a motor control device according to the second embodiment. The configuration of this embodiment is the same as that of the first embodiment (FIG. 1) except for the position detector 4 that detects the rotor phase θdc.

In the second embodiment, the U-phase current having the minimum d-axis voltage is more difficult to detect from the DC bus current than the other phase currents, but the rotor phase θdc detected by the position detector 4 By coordinate-converting the dq-axis current command values (Id ^* and Iq ^* in FIG. 1) to the three-phase current command values, the U-phase current having the minimum d-axis voltage can be obtained.

  According to the present embodiment, as in the first embodiment, in the DC bus current detection method, the current detection width is secured, the current detection accuracy is improved, and the phase shift of the phase voltage pulse for securing the current detection width. Noise generated by the motor can be reduced.

Third Embodiment
FIG. 12 is a vector diagram showing pulse width adjusting means in a motor control apparatus according to a third embodiment of the present invention. Similar to FIG. 6, the directions of three-phase voltage vectors U, V and W, output voltage vectors, correction voltage vectors (solid arrows), and d-axis and q-axis in the rotational coordinate system are shown. The device configuration of this embodiment is the same as that of the first embodiment (FIGS. 1 and 2) described above.

  Unlike the first embodiment (FIG. 6), the direction of the correction voltage in this embodiment is slightly inclined from the direction parallel to the d-axis. That is, the correction voltage set by the above-mentioned correction voltage setting unit 1353 (FIG. 8) has not only the d-axis component but also the q-axis component although it is smaller than the d-axis component.

  According to the present embodiment, although the correction voltage has the q-axis component, the magnitude thereof is smaller than the d-axis component, so that the current detection width is secured in the DC bus current detection method as in the first embodiment. The current detection accuracy is improved, and motor noise generated with the phase shift of the phase voltage pulse for securing the current detection width can be reduced.

Fourth Embodiment
FIG. 13 shows the configuration of an electric brake device according to a fourth embodiment of the present invention.

  As shown in FIG. 13, in the electric brake device 41, the three-phase motor 2 is driven based on the detection value of the operation amount detector 42A that detects the operation amount of the brake pedal 42. The three-phase motor 2 is controlled by the motor control device 3 in any one of the first to third embodiments described above. Thus, the motor torque of the three-phase motor 2 is output to the transmission mechanism 46, whereby the piston 45 is propelled. The movement of the piston 45 generates a fluid pressure inside the master cylinder 43, and the fluid pressure is supplied to the wheel cylinders 44a to 44d. Then, the braking members provided on the wheel cylinders 44a to 44d are pressed by the non-braking members that rotate with the wheels, whereby a braking force corresponding to the operation of the brake pedal 42 is applied to the vehicle.

  In such an electric brake device 41, conventionally, noise and vibration generated by the three-phase motor 2 in the motor control device 3 are transmitted to the driver via the brake pedal 42. In particular, when the motor torque of the three-phase motor 2 is operated in the low torque region as when the brake pedal 42 is lightly depressed, the noise and vibration tend to be felt more strongly. On the other hand, in the present embodiment, since any one of the first to third embodiments described above is applied to the motor control device 3, high frequency noise is reduced in the stopped state or low torque state of the vehicle, Vibration or noise generated by the electrically controlled brake can be reduced.

Fifth Embodiment
FIG. 14 shows a configuration of an electric power steering according to a fifth embodiment of the present invention.

  As shown in FIG. 14, in the electric power steering 51, the rotational torque of the steering wheel 52 is detected by the torque sensor 53, and the controller 1 in the motor control device 3 drives the three-phase motor 2 in accordance with the detected rotational torque. Control. Thus, the motor torque generated by the three-phase motor 2 is output to the steering mechanism 55 via the steering assist mechanism 54. Thus, when the steer link wheel 52 is operated, the tire 56 is steered by the steering mechanism 55 while the electric power steering 51 assists the steering force according to the input of the steering wheel 52.

  In the electric power steering 51, noise and vibration generated by the three-phase motor 2 are transmitted to the driver via the steering wheel 52. In particular, in a state in which the steering wheel 52 is slowly rotated or in a state in which the steering wheel is fixed, the driver feels the vibration and noise of the three-phase motor 2 more strongly. On the other hand, in the present embodiment, any one of the above-described first to third embodiments is applied to the motor control device 3, so that vibration or noise generated by the electric power steering can be reduced.

Sixth Embodiment
FIG. 15 shows the configuration of an electric oil pump system according to a sixth embodiment of the present invention. The electric oil pump system of the present embodiment is used for transmission hydraulic pressure, brake hydraulic pressure, and the like inside a vehicle.

  As shown in FIG. 15, in the pump drive device 4, an oil pump 61 is attached to the three-phase motor 2 of the motor control device 3. The oil pump 61 controls the hydraulic pressure of the hydraulic circuit 62. The hydraulic circuit 62 includes a tank 63 for storing oil, a relief valve 64 for keeping the hydraulic pressure below a set value, a solenoid valve 65 for switching a hydraulic pressure transmission path in the hydraulic circuit 62, and a cylinder 66 operating as a hydraulic actuator.

  The oil pump 61 generates hydraulic pressure by being driven by the motor control device 3 and drives a cylinder 66 which is a hydraulic actuator. In the hydraulic circuit 62, the load of the oil pump 61 is changed by switching the hydraulic pressure transmission path by the solenoid valve 65, and a load disturbance occurs in the motor control device 3. For this reason, the three-phase motor 2 vibrates and noise is generated.

  On the other hand, in the present embodiment, any of the above-described first to third embodiments is applied to the motor control device 3, so vibration is reduced and noise is reduced in the stopped state or low torque state. it can.

  The present invention is not limited to the embodiment described above, and includes various modifications. For example, the embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. In addition, it is possible to add, delete, and replace another configuration for part of the configuration of each embodiment.

  For example, various motors capable of vector control can be applied as a three-phase motor. Moreover, you may apply IGBT (Insulated Gate Bipolar Transistor) etc. as a semiconductor switching element which comprises a power converter.

1 controller 2 three-phase motor 3 motor control device 4 position detector 11 direct current power source 12 current detector 13 control means 14 power converter 41 electric brake device 42 brake pedal 42A operation amount detector 43 master cylinder,
44a, 44b, 44c, 44d brake caliper 45 piston, 46 transmission mechanism 51 electric power steering 52 steering wheel 53 torque sensor 54 steering assist mechanism 55 steering assist mechanism 56 steering mechanism 56 tire 1G command generator 61 oil pump 62 hydraulic circuit 63 tank 64 relief valve 65 Solenoid valve 66 Cylinder 131 Three-phase current detection unit 132 dq axis current conversion unit 133 Voltage command calculation unit 134 Coordinate conversion unit 135 Pulse width adjustment unit 136 Drive signal generation unit 1351 Pulse shift adjustment unit 1352 d axis direction correction phase voltage determination unit 1353 Correction voltage setting unit

Claims (17)

A power converter,
A three-phase motor driven by the power converter;
A three-phase current flowing through the three-phase motor is detected based on a DC bus current, a phase voltage command value is created using the detected three-phase current, and the power converter is generated using the phase voltage command value. Control means for controlling;
In a motor control device comprising
A motor control apparatus characterized in that, when detecting the DC bus current, the control means corrects the phase voltage command value based on a d-axis voltage to shift the phase of the phase voltage pulse. In the motor control device according to claim 1,
The control means
A motor control apparatus characterized by selecting a phase for correcting the phase voltage command value based on the d-axis voltage, and correcting the phase voltage command value of the selected phase by a predetermined amount. In the motor control device according to claim 2,
The motor control device, wherein the control means selects the phase with the largest d-axis voltage and the smallest phase with the d-axis voltage. In the motor control device according to claim 2,
The motor control device, wherein the control means selects only one of the phase with the largest d axis voltage and the phase with the smallest d axis voltage. In the motor control device according to claim 4,
A motor control apparatus characterized in that the control means selects a phase having the largest voltage difference from the intermediate phase of the d-axis voltage among the phase having the largest d-axis voltage and the smallest phase. In the motor control device according to claim 2,
The motor control device, wherein the predetermined amount is a correction amount of the d-axis voltage. In the motor control device according to claim 2,
The motor control device according to claim 1, wherein the predetermined amount is a voltage correction amount including a d-axis component and a q-axis component. In the motor control device according to claim 7,
A motor control apparatus characterized in that the q-axis component is smaller than the d-axis component. In the motor control device according to claim 1,
A motor control apparatus characterized in that the q-axis component of the three-phase current is near zero. In the motor control device according to claim 1,
A motor control apparatus characterized in that an output voltage of the power converter is near zero. In the motor control device according to claim 1,
A motor control apparatus characterized in that the speed of the three-phase motor is near zero. In the motor control device according to claim 1,
A motor control apparatus characterized in that the phase voltage pulse is generated by pulse width modulation using the phase voltage command value as a modulation wave signal. In the motor control device according to claim 4,
The control means
The phase voltage command value is created based on the d-axis component and the q-axis component of the three-phase current, and the d-axis current command value and the q-axis current command value,
A motor control apparatus characterized by detecting the phase current of the phase in which the d-axis voltage is minimum by using the d-axis current command value and the q-axis current command value. A power converter,
A three-phase motor driven by the power converter;
A three-phase current flowing through the three-phase motor is detected based on a DC bus current, a phase voltage command value is created using the detected three-phase current, and the power converter is generated using the phase voltage command value. Control means for controlling;
In a motor control device comprising
The control means
A determination unit that selects a phase for correcting the phase voltage command value based on the d-axis direction voltage;
An adjustment unit that corrects the phase voltage command value of the phase selected by the determination unit by a predetermined amount to shift the phase of the phase voltage pulse;
A setting unit configured to set the predetermined amount in the adjustment unit;
A motor control device characterized by having. A transmission mechanism that outputs motor torque of a three-phase motor driven by a power converter of the motor control device;
A piston moved by the transmission mechanism;
And a master cylinder that generates a hydraulic pressure to be supplied to the wheel cylinder by the movement of the piston.
In the electric brake device, wherein the motor control device controls the power converter based on an operation amount of a brake pedal.
The motor control device is the motor control device according to claim 1. With the steering wheel,
A steering mechanism that steers a tire according to an operation of the steering wheel;
A motor control device that generates a motor torque in accordance with the rotational torque of the steering wheel;
In the electric power steering provided with a steering assist mechanism for transmitting the motor torque to the steering mechanism,
An electric power steering apparatus characterized in that the motor control device is the motor control device according to claim 1. Hydraulic circuit,
A solenoid valve that switches a path of hydraulic pressure in the hydraulic circuit;
An oil pump for controlling the hydraulic pressure of the hydraulic circuit;
A motor control device for driving the oil pump;
In the electric oil pump system provided with
The motor control device is a motor control device according to claim 1.

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