JP2010154598A - Sensorless motor controller and drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a power loss with a low torque by enhancing an accuracy in computation of a positional angle, extending from the low torque (low current) to a high torque (high current). <P>SOLUTION: A sensorless motor controller includes a magnetic pole position estimating means 45, which estimates the position of a magnetic pole in the rotor of a motor by superposing high frequency voltages on the motor, without using a sensor which detects the position of a magnetic pole in the motor 10 that has a rotor having saliency. The controller includes a high frequency voltage control means 33, which changes the magnitude of the high frequency voltages, based on the magnitude of the torque or currents of the motor 10. It controls the magnitude of the high frequency voltages so that the specified high frequency currents of the specified frequency components of motor currents are target high frequency currents. The larger the magnitude of the torque or currents of the motor 10 is, the more it increases the target high frequency currents; and the smaller the magnitude of the torque or currents of the motor 10 is, the more it decreases the target high frequency currents. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive control device for an electric motor, and more particularly to a sensorless vector control device that calculates a position angle of a rotor based on a harmonic current flowing in the electric motor and uses the position angle for vector control calculation. The sensorless motor control device of the present invention can be used, for example, in an electric vehicle (EV) that drives wheels with an electric motor and an electric vehicle (HEV) that includes an electric motor that is driven by an engine and charges a battery.

In Patent Document 1, the harmonic current generated by the harmonic current generator 10 is superimposed (added) to one of the biaxial target currents id and iq of the motor vector control, and the motor voltage is detected and q is calculated from the voltage. The calculation of the position angle focusing on the gap magnetic flux, in which the shaft voltage is calculated, differentiated and the position difference is calculated by the position difference detector 15, is described. Patent Document 2 describes position calculation that calculates an induced voltage of a motor based on a d-axis voltage command for motor vector control, a d-axis current and a q-axis current of the motor, and calculates a position angle θ based on the induced voltage. Has been.
JP 11-299299 A JP 2007-236015 A

  In addition to these, the position angle calculation technique in sensorless drive control of an electric motor by vector control includes applying a high-frequency current to the motor, or focusing on the high-frequency (harmonic) component of the motor current, There is also a high-frequency position angle calculation in which orthogonal L-axis inductances Ld and Lq are estimated based on the voltage, and the position angle is calculated using Ld and Lq as parameters.

  In the calculation of the position angle using the high frequency, attention is paid to the orthogonal two-axis inductances Ld and Lq. However, because the harmonic current injected into the motor or the harmonic component of the motor current causes power loss in the motor and noise is generated. The harmonic current or the harmonic current is preferably small, but if it is small, the S / N ratio for calculating Ld and Lq is lowered, and the error in calculating the position angle becomes large.

  In addition, in small high-power motors often used in in-vehicle motors, the higher the torque (high current) drive, the more magnetic saturation occurs, and the salient pole ratio (Lq / Ld) decreases (close to 1). The accuracy of is reduced. That is, the harmonic current or the orthogonal biaxial inductances Ld and Lq with respect to the harmonic current are dynamic inductances as shown in FIG. 5 that are tangent angles of the stator I / φ curve, but in the vicinity of the saturation range of the I / φ curve. That is, in the high torque (high current) region, both Ld and Lq are close to 0, the amount of change in Ld and Lq is small with respect to the level change in current I, and Ld and Ld based on the harmonic current or harmonic current and voltage. The S / N ratio of the Lq calculated value decreases, and the accuracy of position angle calculation using Ld and Lq as parameters decreases.

  An object of the present invention is to increase the accuracy of position angle calculation from low torque (low current) to high torque (high current) and to suppress power loss at low torque (low current).

(1) A magnetic pole for estimating the magnetic pole position of the rotor of the electric motor by superimposing a harmonic voltage on the electric motor without using a sensor for detecting the magnetic pole position of the electric motor (10) having a rotor having saliency. In a sensorless motor control device comprising position estimation means (45);
A sensorless motor control device comprising: harmonic voltage control means (33) for changing the magnitude of the harmonic voltage based on the torque or current magnitude of the electric motor (10).

  In addition, in order to make an understanding easy, the code | symbol of the response | compatibility of an Example shown in drawing or an equivalent element or a matter, or an equivalent element or matter was added as reference for reference. The same applies to the following.

As a result, at high torque where the current value of the motor is large, the salient pole ratio (Lq / Ld) becomes small due to magnetic saturation, so the position angle detection accuracy deteriorates. Conversely, at low torque where the current value of the motor is small, Since the pole ratio (Lq / Ld) is large, the position angle detection accuracy can be ensured. For this reason, by improving the harmonic voltage (Vdh ^* , Vqh ^* ) based on the magnitude of the torque or current of the motor, the position angle calculation accuracy is improved and the power loss and noise are suppressed. Can be made compatible.

(2) The harmonic voltage control means (33) controls the magnitude of the harmonic voltage so that the specific harmonic current of the specific frequency component of the electric motor current becomes a target harmonic current, The target harmonic current is increased as the magnitude of the torque or current of the motor is increased, and the target harmonic current is decreased as the magnitude of the torque or current of the motor is decreased;
The magnetic pole position estimating means (45) estimates a magnetic pole position based on the specific harmonic current;
The sensorless motor control device according to (1) above.

  That is, a harmonic current level control system for controlling the level of harmonic current generated by the motor to a target value used for calculating the position angle is configured, and by operating the target value, a high torque with a large motor current value is obtained. Then, increase the target value to increase the harmonic current level to reduce the position angle calculation error, and at low torque with a small motor current value, the position angle calculation accuracy is high. To reduce power loss and noise due to harmonic current.

  (3) The harmonic voltage control means (33) controls the magnitude of the harmonic voltage so that a specific harmonic current of a specific frequency component of the current of the electric motor becomes a target harmonic current, Amplitude data (35) of the target harmonic current corresponding to the torque or current of the motor, and the amplitude of the specific harmonic current is the target amplitude obtained from the amplitude data of the target harmonic current. The sensorless motor control device according to claim 2, comprising means (34, 36 to 39) for controlling the specific harmonic voltage.

  According to this, amplitude data can be easily obtained and the specific harmonic current can be easily controlled.

(4) The sensorless motor control device further converts a three-phase current of the first motor into an orthogonal biaxial current, and a biaxial voltage command value (Vd) for matching the orthogonal biaxial current with the orthogonal biaxial target current. ^* , Vq ^* ), a vector control unit (31, 32, 41 to 49) for controlling the first electric motor by converting the two-axis voltage command value into a three-phase voltage command value;
The harmonic voltage control means (33) superimposes the harmonic voltage on the biaxial voltage command value (Vd ^* , Vq ^* ), and the specific harmonic current is a specific frequency component of the orthogonal biaxial current. Yes; The sensorless motor control device according to any one of (1) to (3) above.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  FIG. 1 shows an outline of the first embodiment of the present invention. In this embodiment, an electric motor 10 that is a motor to be controlled is a permanent magnet embedded synchronous motor that is mounted on a vehicle and rotationally drives wheels, and has a permanent magnet built in a rotor. Includes three-phase coils 11 to 13 of U phase, V phase and W phase. A voltage type inverter 16 supplies electric power of a battery 17 on the vehicle to the electric motor 10.

  A battery 17 that is a storage battery on the vehicle is connected to a primary side capacitor 18 when an electrical component on the vehicle is turned on, and constitutes a primary side DC power source together with the battery 17. Voltage sensor 19 provides voltage detection signal Vdc representing the voltage of primary side capacitor 18 (the voltage of on-vehicle battery 17) to motor control device 30. In this embodiment, a voltage dividing resistor is used for the voltage sensor 19. One end of the reactor 21 of the converter 20 is connected to the positive electrode (+ line) of the primary side DC power supply.

  The converter 20 further includes a step-up semiconductor switch 22 that is a step-up switching element for turning on and off between the other end of the reactor 21 and the negative electrode (−line) of the primary side DC power supply, and the positive electrode of the secondary capacitor 27. And the other end are a regenerative semiconductor switch 23 which is a regenerative switching element for turning on and off, and respective diodes 24 and 25 connected in parallel to the respective semiconductor switches 22 and 23.

  When the step-up semiconductor switch 22 is turned on (conductive), a current flows from the primary DC power supply (17, 18) to the switch 22 via the reactor 21, whereby the reactor 21 stores electricity and the switch 22 is turned off (non-conductive). ), The reactor 21 discharges high voltage to the secondary capacitor 27 through the diode 25. That is, a voltage higher than the voltage of the primary side DC power supply is induced to charge the secondary side capacitor 27. By repeatedly turning on and off the switch 22, high voltage charging of the secondary capacitor 27 is continued. That is, the secondary side capacitor 27 is charged with a high voltage. If this ON / OFF is repeated at a constant cycle, the electric power stored in the reactor 21 increases according to the length of the ON period, so the ON time during the fixed cycle (ON duty: ON time ratio with respect to the fixed cycle) , Ie, by PWM control, the speed at which power is supplied from the primary side DC power supplies 17 and 18 to the secondary capacitor 27 via the converter 20 (powering speed for powering) can be adjusted.

  When the regenerative semiconductor switch 23 is turned on (conductive), the power stored in the secondary side capacitor 27 is supplied to the primary side DC power sources 17 and 18 through the switch 23 and the reactor 21 (reverse power feeding: regeneration). In this case as well, by adjusting the ON time of the switch 23 during a certain period, that is, by PWM control, the speed at which power is reversely supplied from the secondary capacitor 27 to the primary DC power supplies 17 and 18 via the converter 20 ( The power supply speed for regeneration) can be adjusted.

  The voltage type inverter 16 includes six switching transistors Tr1 to Tr6, and the transistors Tr1 to Tr6 are turned on (conducted) by each series of six series of drive signals generated in parallel by the drive circuit 29, so that the secondary operation is performed. The DC voltage of the side capacitor 27 (the output voltage of the converter 20, that is, the secondary voltage) is converted into a triple AC voltage having a phase difference of 2π / 3, that is, a three-phase AC voltage. (Phase, V phase, W phase) stator coils 11-13. Thereby, each phase current iU, iV, iW flows to each of the stator coils 11 to 13 of the electric motor 10, and the rotor of the electric motor 10 rotates. In order to increase the power supply capability for on / off driving (switching) of the transistors Tr1 to Tr6 by the PWM pulse and to suppress the voltage surge, the secondary output line of the converter 20, which is the input line of the inverter 16, A large-capacity secondary capacitor 27 is connected. On the other hand, the primary side capacitor 18 constituting the primary side DC power supply is small and low-cost and has a small capacity, and the capacity of the primary side capacitor 18 is considerably larger than the capacity of the secondary side capacitor 27. small. Voltage sensor 28 detects secondary voltage Vuc of converter 20 and provides it to motor control device 30. Current sensors 14 and 15 using Hall ICs are attached to power supply lines connected to the stator coils 11 and 12 of the electric motor 10, respectively, and detect phase currents iV and iW to detect current signals (analog voltage). Is supplied to the motor control device 30.

  FIG. 2 shows a functional configuration of the motor control device 30. In this embodiment, the motor control device 30 is an electronic control device mainly composed of a DSP (Digital Signal Processor), and includes a drive circuit 29, current sensors 14 and 15, a primary voltage sensor 19, and a secondary voltage sensor 28. And an interface (communication circuit) (not shown) with the main controller of the vehicle travel control system (not shown) on the vehicle.

  Referring to FIG. 2, the position calculation 45 calculates the rotation angle (magnetic pole position) θ of the rotor of the electric motor 10, and the speed calculation 46 calculates the rotation speed (angular speed) ω based on the rotation angle θ. To be precise, the rotation angle of the rotor of the electric motor 10 and the magnetic pole position are not the same, but they are in a proportional relationship, and the proportionality coefficient is determined by the number of magnetic poles p of the electric motor 10. Further, although the rotational speed and the angular speed are not the same, both are in a proportional relationship, and the proportionality coefficient is determined by the number of magnetic poles p of the electric motor 10. In this document, the rotation angle θ means the magnetic pole position. The rotational speed ω means an angular speed, but sometimes means a rotational speed.

A main controller of the vehicle travel control system (not shown) supplies the motor target torque TM ^* to the control device 30 of the motor control device 30. The main controller calculates a vehicle required torque TO ^* based on the vehicle speed and the accelerator opening of the vehicle, generates a motor target torque TM ^* corresponding to the vehicle required torque TO ^* , and controls the control device 30. To give. The control device 30 outputs the rotation speed ω rpm of the electric motor 10 to the main controller.

The motor control device 30 reads the upper limit value Vmax of the output voltage (secondary voltage) of the converter 20 and the limit torque TM ^* max corresponding to the rotational speed ω from the limit torque table (lookup table) by the torque command limit 31. When the target torque TM * exceeds TM ^* max, TM ^* max is determined as the target torque T ^* . When TM * max or less, the motor target torque TM ^* is determined as the target torque T ^* . The motor target torque T ^* generated by adding such a restriction is given to the output calculation 32 and used for calculating the secondary target voltage.

In the limit torque table, each value of the upper limit value Vmax of the secondary voltage and the voltage within the rotation speed range is used as an address, and the maximum torque that can be generated in the electric motor 10 at each value is set as the limit torque TM ^* max. This is a written memory area, and in this embodiment means one memory area of a RAM (not shown) in the control device 30. The limit torque TM ^* max is larger as the upper limit value Vmax of the secondary voltage is higher, and is smaller as it is lower. Further, the lower the rotation speed ω, the larger the value, and the smaller the rotation speed ω, the smaller.

In the motor control device 30, there is a non-volatile memory in which the limit torque table data TM ^* max is written. When the operating voltage is applied to the control device 30, the control device 30 itself and the motor drive shown in FIG. In the process of initializing the system, data is read from the nonvolatile memory and written to the RAM. The control device 30 has a plurality of other similar look-up tables, which will be described later. These also mean the memory area on the RAM in which the reference data in the nonvolatile memory is written, like the limit torque table. To do.

The motor control device 30 determines whether it is “powering” or “regeneration” based on the target torque T ^* and the rotational speed ω, and if it is “powering”, if it is “regeneration” in the “powering” group, The secondary target voltage Vuc ^* assigned to the rotational speed ω of the electric motor 10m is read from the secondary target voltage table assigned to the target torque T ^* in the “regeneration” group, and the secondary voltage detected by the sensor 28 is the target. The drive circuit 26 is disconnected to control the converter 20 so as to match the voltage Vuc ^* .

  The motor control device 30 takes the d-axis in the direction of the magnetic pole pair in the rotor of the electric motor 10 and the q-axis in the direction perpendicular to the d-axis by the output calculation 32, the motor current control 42, and the voltage conversion 43. Motor current feedback control is performed by a vector control calculation on a known dq axis model. Therefore, the control device 30 digitally converts and reads the current detection signals iV and iW of the current sensors 14 and 15, and uses a three-phase / two-phase conversion which is a known fixed / rotational coordinate conversion in the current feedback calculation 49. The three-phase current values iU, iV, iW on the fixed coordinates are converted into the two-phase current values id, iq on the d-axis and the q-axis on the rotation coordinates. Since iU + iV + iW = 0, iU is calculated based on this.

A first high efficiency torque curve table A, which is one look-up table, is included in the output calculation 32, and each of the first high efficiency torque curve tables A is associated with the motor speed ω and the motor target torque T ^*. Each d-axis current value id for generating each target torque T * at the motor speed is written.

The output torque of the electric motor is determined corresponding to each value of the d-axis current id and the q-axis current iq, but id for outputting the same torque for one rotation speed value, that is, at the same motor rotation speed. , Iq are innumerable and are on a constant torque curve. On the constant torque curve, there is a combination of id and iq with the highest power usage efficiency (lowest power consumption), which is the high efficiency torque point. A curve connecting high efficiency torque points on a plurality of torque curves is a high efficiency torque curve and exists for each rotation speed. By energizing the electric motor 10 with the d-axis current id and the q-axis current iq at the position of the given motor target torque T ^* on the high efficiency torque curve addressed to the rotation speed of the motor as the target current values, The electric motor 10 outputs the torque T ^* , and the power use efficiency of the motor energization is high.

  In this embodiment, the high-efficiency torque curve is divided into two systems: a first high-efficiency torque curve A that represents the d-axis value and a second high-efficiency torque curve B that represents the q-axis value. The high-efficiency torque curve A is a pair of the one applied to the power running region and the one applied to the regeneration region, and both represent the d-axis target current with respect to the motor rotation speed and the target torque.

The first high-efficiency torque curve table A is a memory area in which a d-axis target current for generating the target torque with the minimum power consumption, which is addressed to the target torque T *, is written. A pair of regeneration tables A2 for regeneration is configured. Whether to use a table for power running or regeneration is determined according to the determination result by determining whether the table is power running or regeneration based on the rotational speed ω of the electric motor and the target torque T ^* to be given.

In calculating the d-axis current command in the “output calculation” 32, the control device 30 reads the d-axis current value read from the first high-efficiency torque curve table A corresponding to the target torque T ^* determined by the torque command limitation. By subtracting the d-axis field weakening current Δid from id, the d-axis target current id ^* is calculated as id ^* = − id−Δid.

  In the calculation of the q-axis current command, the second high efficiency torque curve table B in the output calculation 32 is used. The second high-efficiency torque curve table B further includes a second high-efficiency torque curve B representing the q-axis value of the high-efficiency torque curve, and a d-axis field weakening current Δid and a pair of q-axis field weakening current Δiq. The data is corrected to a curve representing the subtracted q-axis target current, and the data of the corrected second high efficiency torque curve B is stored. The second high-efficiency torque curve table B is the d-axis target current for generating the target torque with the lowest power consumption, which is assigned to the target torque T * and the d-axis field weakening current Δid. This is a memory area in which the target current value of the high-efficiency torque curve B is written, and this is also composed of a pair of a power running table B1 for power running and a regeneration table B2 for regeneration. Whether to use powering or regenerative power is determined based on the determination result by determining whether it is powering or regenerating based on the rotational speed ω of the electric motor and the target torque T *.

In calculating the q-axis current command, the q-axis target current iq ^* addressed to the target torque T * and the d-axis field weakening current Δid is read from the second high efficiency torque curve table B and used as the q-axis current command.

The motor controller 30 performs subtraction 41d, 41q and motor current control 42 to determine the current deviation δid between the d-axis target current id ^* and the d-axis current id and the current between the q-axis target current iq ^* and the q-axis current iq. Deviation δiq is calculated, proportional control and integral control (PI calculation of feedback control) are performed based on each current deviation δid, δiq, and based on the output, voltage conversion 43 performs d-axis voltage as output voltage The command value vd ^* and the q-axis voltage command value vq ^* are calculated.

Next, in the two-phase / three-phase conversion 47 which is the rotation / fixed coordinate conversion, the target voltages vd ^* and vq ^* on the rotation coordinates are changed to the three-phase target voltage VU ^* on the fixed coordinates according to the two-phase / three-phase conversion ^. , VV ^* , VW ^* , and sent to the PWM pulse generator 48. When the voltage control mode is two-phase modulation, it is modulated to a two-phase target voltage and sent to the PWM pulse generator 48. When each phase target voltage is given, the PWM pulse generator 48 converts the voltage of each value into PWM pulses MU, MV, and MW, and outputs them to the drive circuit 29 shown in FIG. . The drive circuit 29 generates six series of drive signals in parallel based on the PWM pulses MU, MV, and MW, and turns on / off each of the transistors Tr1 to Tr6 of the voltage type inverter 16 with each series of drive signals. . Thereby, each phase target voltage is applied to each of the stator coils 11 to 13 of the electric motor 10, and the phase currents iU, iV and IW flow. When each phase target voltage in the two-phase modulation mode is given, the PWM pulse generator generates a PWM pulse for two phases and an on or off (constant voltage output) signal for the remaining one phase. When each phase target voltage in the 1 pulse modulation mode is given, an energization section signal for making each phase a rectangular wave energization is output.

In the field weakening current calculation, a voltage saturation index m that is a parameter for field weakening control is calculated. That is, based on the d-axis voltage command value vd ^* and the q-axis voltage command value vq ^* , the voltage saturation calculation value ΔV is calculated as a value representing the degree of voltage saturation, and the field adjustment allowance is calculated. In calculating the field adjustment allowance, when ΔV is integrated and the integrated value ΣΔV takes a positive value, the integrated value ΣΔV is multiplied by a proportional constant to calculate a d-axis field weakening current Δid for performing field weakening control. When the voltage saturation calculation value ΔV or the integrated value ΣΔV takes a value less than or equal to zero, the adjustment value Δid and the integrated value ΣΔV are set to zero. The adjustment value Δid is used in the calculation of the d-axis current command and the q-axis current command.

  The rotor rotation angle (magnetic pole position) θ, which is the position angle of the rotor, is determined by the position calculation 45 based on the harmonic current (specific harmonic current) of a specific frequency included in the three-phase current of the motor 10 and its voltage. It is calculated by a position angle calculation via orthogonal two-axis inductances Ld and Lq corresponding to harmonics. The calculated position angle θ is used for calculating the motor rotation speed ω in the speed calculation 46, and is also used for phase conversion in the 2-phase / 3-phase conversion 47 and 3-phase / 2-phase conversion.

In this embodiment for controlling the harmonic current level of the motor 10, the harmonic voltage control 33A reduces the specific harmonic current flowing through the motor 10 to a low level at a low target torque (low current value) and a high target torque. Accordingly, specific harmonic voltage commands Vdh ^* and Vqh ^* for controlling to a high level are generated and added to the orthogonal biaxial target voltage values Vd ^* and Vq ^* by addition and subtraction 44d and 44q. As a result, the two-phase / three-phase conversion 47 is given a voltage command in which the specific harmonic voltage commands Vdh ^* and Vqh ^* are superimposed. Specific harmonics extracted by the bandpass filter 50 from the specific harmonic voltage commands Vdh ^* and Vqh ^* (instantaneous values) generated by the harmonic voltage control 33A and the two-phase current values id and iq calculated by the current feedback calculation 49 Currents idh and iqh (in this example, the fifth or sixth harmonic) are supplied to the position calculation 45, and the position calculation 45 calculates and outputs the position angle θ corresponding to these values.

In the harmonic voltage control 33A of the present embodiment, amplitude calculation 34 for calculating the amplitudes of the specific harmonic currents idh and iqh, and specific harmonic amplitude data associated with each target torque using each target torque value as an address. There is a stored harmonic amplitude table (data group of one area of RAM) 35a. The specific harmonic amplitude (target amplitude of the specific harmonic current) associated with the target torque T ^* is read from the table 35a. On the other hand, the amplitude calculation 34 calculates the amplitude Ai (feedback value) of the vector composite value of the specific harmonic currents idh, iqh (extracted by the band pass filter 50) flowing in the motor 10. The difference of the feedback amplitude with respect to the target amplitude read from the table 35 a is given to PI (proportional / integral) 37, 37, the PI calculation value is limited by the limiter 38, and the specific harmonic voltage is applied by the voltage conversion 39. It is converted into commands Vdh ^* and Vdqh ^* and output to additions 44d and 44q and position calculation 45. That is, the harmonic voltage control 33A of the first embodiment performs feedback control for controlling the specific harmonic currents idh and iqh of the motor 10 to the target amplitude.

  In the harmonic amplitude table 35a, the higher the value, the lower the specific harmonic amplitude corresponding to each value of the target torque, and the lower the specific harmonic amplitude, so that the position angle is calculated at high torque (high current). And the power loss at low torque (low current) is reduced.

FIG. 3 shows a functional configuration of the motor control device 30 of the second embodiment. In this second embodiment, the vector combined value of the d-axis current id and q-axis current obtained by converting the three-phase current of the motor into the orthogonal two-axis value by the three-phase / two-phase conversion, that is, the target current value io in the orthogonal two-axis coordinates. Is calculated by the vector calculation 40. The table 35b stores specific harmonic amplitude (target amplitude) with each value of the target current value io corresponding to the target torque T ^* as an address. Specific harmonic currents idh and iqh (extracted by the bandpass filter 50) calculated by the amplitude calculation 34 for the specific harmonic amplitude (target amplitude) associated with the current target current value io read from the table 35b. The difference of the amplitude Ai (feedback value) of the vector composite value is given to PI (proportional / integral) 37, 37, the PI operation value is limited by the limiter 38, and the specific harmonic voltage is applied by the voltage converter 39. It is converted into commands Vdh ^* and Vdqh ^* and output to the additions 44d and 44q and the position calculation 45. That is, the harmonic voltage control 33B of the second embodiment also performs feedback control for controlling the specific harmonic currents idh and iqh of the motor 10 to the target amplitude. Other configurations and functions of the second embodiment are the same as those of the first embodiment.

FIG. 4 shows a functional configuration of the motor control device 30 of the third embodiment. In the third embodiment, the specific harmonic amplitude (target amplitude) is stored in the table 35c of the high-frequency current control 33C with each value of the motor current value (feedback value) as an address. A vector composite value of the d-axis current id and q-axis current obtained by converting the three-phase current of the motor into a quadrature biaxial value by the three-phase / two-phase conversion 49, that is, the motor current value (feedback current value) if in the quadrature biaxial coordinates. The vector calculation 51 calculates. The calculated value (instantaneous value) is smoothed (DC converted) by the low-pass filter 52, the specific harmonic amplitude (target amplitude) corresponding to the calculated value (motor current value) is read from the table 35c, The difference of the amplitude Ai (feedback value) of the vector composite value of the specific harmonic currents idh, iqh (extracted by the bandpass filter 50) calculated by the amplitude calculation 34 is given to PI (proportional / integral) 37, 37, The PI calculation value is limited to the upper and lower limits by the limiter 38, and converted to specific harmonic voltage commands Vdh ^* and Vdqh ^* by the voltage conversion 39 and output to the additions 44 d and 44 q and the position calculation 45. That is, the harmonic voltage control 33C of the third embodiment also performs feedback control for controlling the specific harmonic currents idh and iqh of the motor 10 to the target amplitude. Other configurations and functions of the third embodiment are the same as those of the first embodiment described above.

It is a block diagram which shows the structure of the electric system of the wheel drive device of one Example of this invention. It is a block diagram which shows the function structure of 1st Example of the motor control apparatus 30 shown in FIG. It is a block diagram which shows the function structure of 2nd Example of the motor control apparatus 30 shown in FIG. It is a block diagram which shows the function structure of 3rd Example of the motor control apparatus 30 shown in FIG. It is a graph which shows the outline of the relationship between the energization current value of the stator of a permanent magnet embedded synchronous motor, and magnetic flux.

Explanation of symbols

10: Electric motors 11-13: Three-phase stator coils 14, 15: Current sensor 17: Battery 18 on vehicle: Primary capacitor 19: Primary voltage sensor 21: Reactor 22: Switching element (for boosting)
23: Switching element (for step-down)
24, 25: Diode 27: Secondary side capacitor 28: Secondary voltage sensor Vdc: Primary voltage (battery voltage)
Vuc: secondary voltage (boost voltage)

Claims (4)

Magnetic pole position estimating means for estimating the magnetic pole position of the rotor of the electric motor by superimposing a harmonic voltage on the electric motor without using a sensor for detecting the magnetic pole position of the electric motor having a rotor having saliency. In the sensorless motor control device,
A sensorless motor control device, comprising: harmonic voltage control means for changing the magnitude of the harmonic voltage based on the magnitude of torque or current of the motor. The harmonic voltage control means controls the magnitude of the harmonic voltage so that the specific harmonic current of the specific frequency component of the current of the electric motor becomes a target harmonic current, and the torque or current of the electric motor The larger the magnitude, the larger the target harmonic current, and the smaller the magnitude of the motor torque or current, the smaller the target harmonic current;
The magnetic pole position estimating means estimates the magnetic pole position based on the specific harmonic current;
The sensorless motor control device according to claim 1.   The harmonic voltage control means controls the magnitude of the harmonic voltage so that the specific harmonic current of the specific frequency component of the electric current of the motor becomes a target harmonic current, and the torque or current of the motor A means for controlling the specific harmonic voltage so that the amplitude data of the corresponding harmonic current of the target and the amplitude of the specific harmonic current become the target amplitude obtained from the amplitude data of the target harmonic current; The sensorless motor control device according to claim 2. The sensorless motor control device further converts a three-phase current of the first motor into an orthogonal biaxial current, calculates a biaxial voltage command value for matching the orthogonal biaxial current with the orthogonal biaxial target current, Including a vector control unit for controlling the first electric motor by converting a biaxial voltage command value into a three-phase voltage command value;
The harmonic voltage control means superimposes the harmonic voltage on the biaxial voltage command value, and the specific harmonic current is a specific frequency component of the orthogonal biaxial current; The sensorless electric motor control device according to one.

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