JP2018137869A - Motor driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress sudden change in output torque when a control mode is switched between a rectangular wave control mode and other control mode and suppress variations in output torque of a motor 22 by disturbance.SOLUTION: When an inverter is controlled in a rectangular wave control mode, using a current of each phase and a rotation angle of a motor, a torque average value of the motor is calculated. Using the current of each phase of the motor, a voltage of each phase of the motor, and rotation speed of the motor, an amount of variations in torque of the motor is calculated. A torque average value corrected by the amount of variations in torque is estimated to be output torque of the motor. An inverter is controlled such that the motor is adapted to be driven at target torque using the estimated output torque.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a motor drive device, and more particularly, to a motor drive device including an inverter and a control device.

  Conventionally, as this kind of motor drive device, what is provided with the inverter for driving a motor is proposed (for example, refer to patent documents 1). In this apparatus, the inverter is controlled in a plurality of control modes including a rectangular wave control mode so that the motor is driven with the target torque. When controlling the inverter in the rectangular wave control mode, the d-axis current and the q-axis current are calculated using each phase current of the motor and the rotation angle of the motor, and the calculated d-axis current, q-axis current and torque are calculated. The motor output torque is estimated using the calculation map. Then, the inverter is controlled by adjusting the voltage phase of the rectangular wave voltage so that the difference between the estimated value of the output torque of the motor and the torque command of the motor becomes 0.

JP 2007-159368 A

  In the motor drive device described above, when the inverter is controlled in the rectangular wave control mode, if the rotational speed of the motor varies due to disturbance, an error occurs in the estimated output torque of the motor due to the detection delay of the rotational angle of the motor. May occur. As a technique for suppressing the occurrence of such an error, a technique for estimating the output torque of the motor without using the rotation angle of the motor can be considered. However, in general, in a control mode different from the rectangular wave control mode, the inverter is controlled using the d-axis current and the q-axis current calculated using each phase current of the motor and the rotation angle of the motor. If the output torque of the motor is estimated without using the rotation angle of the motor, the output torque changes suddenly when the control mode is switched between the rectangular wave control mode and another control mode.

  The motor drive device according to the present invention mainly suppresses a sudden change in the output torque when the control mode is switched between the rectangular wave control mode and another control mode, and suppresses a change in the output torque of the motor due to a disturbance. Objective.

  The motor driving apparatus of the present invention employs the following means in order to achieve the main object described above.

The motor drive device of the present invention is
An inverter that drives the motor;
A control device for controlling the inverter in a plurality of control modes including a rectangular wave control mode so that the motor is driven with a target torque;
A motor drive device comprising:
The control device, when controlling the inverter in the rectangular wave control mode, calculates an average torque value of the motor using a current of each phase of the motor and a rotation angle of the motor, and each phase of the motor. The torque fluctuation amount of the motor is calculated using the current of the motor, the voltage of each phase of the motor, and the rotation speed of the motor, and the torque obtained by correcting the torque average value with the torque fluctuation amount is calculated as the output torque of the motor. Controlling the inverter so that the motor is driven with the target torque using the estimated output torque,
This is the gist.

  In the motor driving device of the present invention, when controlling the inverter in the rectangular wave control mode, the motor torque average value is calculated using the current of each phase of the motor and the rotation angle of the motor, and the current of each phase of the motor is calculated. The torque fluctuation amount of the motor is calculated using the voltage of each phase of the motor and the rotation speed of the motor, the torque obtained by correcting the average torque value by the torque fluctuation amount is estimated as the motor output torque, and the estimated output torque is calculated. Used to control the inverter so that the motor is driven with the target torque. In general, in a control mode different from the rectangular wave control mode, an estimated value of torque output from the motor is calculated using the current of each phase of the motor and the rotation angle of the motor, and an inverter is calculated using the calculated estimated value. To control. Therefore, in the rectangular wave control mode, when the inverter is controlled by estimating the motor output torque using a state quantity different from that in the other control mode, the rectangular wave control mode and the other control mode are When the control mode is switched between, the torque actually output from the motor may change suddenly. In the motor drive device of the present invention, in the rectangular wave control mode, the same amount of state as in the other control modes, that is, the motor torque average value is calculated using the current of each phase of the motor and the rotation angle of the motor. The torque fluctuation amount of the motor is calculated using the current of each phase of the motor, the voltage of each phase of the motor and the rotation speed of the motor, and the torque obtained by correcting the torque average value by the torque fluctuation amount is estimated as the motor output torque. Since the inverter is controlled so that the motor is driven with the target torque using the estimated output torque, sudden changes in the output torque from the motor when the control mode is switched between the rectangular wave control mode and another control mode are suppressed. can do. In addition, if an error occurs in the rotation angle detected due to the detection delay of the rotation angle of the motor, the torque average value calculated using the current of each phase of the motor and the rotation angle of the motor becomes a value with an error. The torque fluctuation amount calculated using the current of each phase of the motor, the voltage of each phase of the motor, and the rotation speed of the motor has little effect even if an error occurs in the detected rotation angle. Therefore, by estimating the torque average value corrected with the torque fluctuation amount that is less affected by the rotational angle error as the motor output torque, fluctuations in the rotational speed of the motor will occur due to disturbances, and detection of the rotational angle of the motor will be performed. Even when a delay occurs, the deviation between the estimated output torque of the motor and the torque actually output from the motor can be suppressed. Since the inverter is controlled using the estimated output torque of the motor in this way, fluctuations in the output torque of the motor due to disturbance can be suppressed. As a result, it is possible to suppress a sudden change in output torque when the control mode is switched between the rectangular wave control mode and another control mode, and to suppress fluctuations in the output torque of the motor due to disturbance.

  In such a motor driving device of the present invention, when the control device controls the inverter in the rectangular wave control mode, the torque average value is obtained when a fluctuation amount of the rotation speed of the motor is equal to or larger than a predetermined fluctuation amount. The torque fluctuation amount is calculated, the torque obtained by correcting the torque average value by the torque fluctuation amount is estimated as the output torque of the motor, and the motor is used as the target torque by using the estimated output torque. The inverter may be controlled to drive. Here, the “predetermined fluctuation amount” is a threshold value for determining whether the rotation speed of the motor has fluctuated due to disturbance. In this way, fluctuations in the output torque of the motor can be suppressed when the rotational speed of the motor fluctuates due to disturbance.

  In the motor drive device of the present invention, when the control device controls the inverter in the rectangular wave control mode, the fluctuation amount of the rotation speed of the motor is equal to or greater than a predetermined fluctuation amount, and the motor When the fluctuation amount of the estimated output torque calculated using the current of each phase and the rotation angle of the motor is equal to or greater than a predetermined torque fluctuation amount, the torque average value is calculated, and the torque fluctuation amount is calculated. A torque obtained by correcting the torque average value by the torque fluctuation amount is estimated as an output torque of the motor, and the inverter is controlled so that the motor is driven by the target torque using the estimated output torque. . Here, the “predetermined torque fluctuation amount” is a threshold value for determining whether or not the estimated output torque is actually fluctuating. In this way, when the rotational speed of the motor fluctuates due to disturbance and the estimated output torque fluctuates, that is, the estimated output torque fluctuates due to the fluctuation of the motor rotational speed due to the disturbance. When the motor is running, fluctuations in the output torque of the motor can be suppressed.

  Furthermore, in the motor drive device of the present invention, the plurality of control modes may include the rectangular wave control mode and a PWM control mode. In this case, in the PWM control mode, the inverter may be controlled using a d-axis current and a q-axis current calculated using the current of each phase of the motor and the rotation angle.

It is a block diagram which shows the outline of a structure of the drive device 20 provided with the motor drive device as one Example of this invention. FIG. 6 is an explanatory diagram for explaining an example of a relationship between a rotational speed Nm of a motor 22, a torque command Tm *, and a control mode Md of an inverter 24. FIG. 4 is a block diagram for explaining control of an inverter 24 in a rectangular wave control mode in the drive device 20. 4 is a flowchart illustrating an example of a corrected torque setting process routine executed by a control device 50. It is explanatory drawing which shows the relationship between the electric currents Id and Iq of d axis | shaft and q axis | shaft, and the torque output from the motor 22. FIG. It is explanatory drawing which shows an example of a time change of the estimation output torque Trq1 when the rotation speed Nm of the motor 22 is fluctuated by disturbance, and the actual torque Tmr actually output from the motor 22. A voltage phase command θp * when the estimated output torque Trq1 is subjected to rectangular control feedback calculation using the corrected torque Trq, and a voltage phase command θp when the actual output torque Trq actually output is calculated using the rectangular control feedback calculation * (Ideal voltage phase command θpr) and an explanatory diagram showing an example of a time change.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a drive device 20 including a motor drive device as an embodiment of the present invention. The drive device 20 according to the embodiment is configured as a device that drives a drive shaft mounted on a vehicle and connected to an axle connected to a drive wheel via a differential gear. And an inverter 24, a battery 26, and a control device 50.

  The motor 22 is configured as a synchronous generator motor, and includes a rotor in which a permanent magnet is embedded and a stator around which a three-phase coil is wound.

  The inverter 24 is connected to the motor 22 and to the battery 26. The inverter 24 includes six transistors T11 to T16 and six diodes D11 to D16. Two transistors T11 to T16 are arranged in pairs so as to be on the source side and the sink side with respect to the positive and negative buses of the power line from the battery 26, respectively. The six diodes D11 to D16 are respectively connected in parallel to the transistors T11 to T16 in the reverse direction. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor 22 is connected to each connection point between the transistors T11 to T16. Therefore, when the voltage is applied to the inverter 24, the control device 50 adjusts the ratio of the on-time of the paired transistors T11 to T16, so that a rotating magnetic field is formed in the three-phase coil, and the motor 22 Is driven to rotate.

  The battery 26 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery.

  The control device 50 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU.

  Signals from various sensors are input to the control device 50 via input ports. Examples of the signal input to the control device 50 include a rotation angle θm of the rotor of the motor 22 from a rotation angle detection sensor (for example, a resolver) 22 a that detects the rotation position of the rotor of the motor 22, The phase currents Iu and Iv flowing from the current sensors 22u and 22v for detecting the current flowing in the phase to the motor 22 and the voltages Vu, Vv and Vw of the voltage sensors 22b, 22c and 22d for detecting the voltage of each phase of the motor 22 are listed. be able to. Moreover, the voltage Vb from the voltage sensor 26a attached between the terminals of the battery 26 and the current Ib from the current sensor 26b attached to the output terminal of the battery 26 can also be mentioned.

  Various control signals are output from the control device 50 via an output port. As a signal output from the control apparatus 50, the switching control signal to the transistors T11-T16 of the inverter 24 can be mentioned, for example. The control device 50 calculates the rotation angle θm of the rotor of the motor 22 and the rotation speed Nm of the motor 22 from the rotation angle detection sensor 22a. In addition, control device 50 calculates storage ratio SOC of battery 26 based on the integrated value of current Ib of battery 26 from current sensor 26b. Here, the storage ratio SOC is a ratio of the capacity of electric power that can be discharged from the battery 26 to the total capacity of the battery 26.

  In the drive device 20 of the embodiment thus configured, the control device 50 performs switching control of the transistors T11 to T16 of the inverter 24 so that the motor 22 is driven by the torque command Tm *.

  Here, the control of the inverter 24 will be described. In the embodiment, for the inverter 24, a sine wave PWM (pulse width modulation) control mode, an overmodulation PWM control mode, a rectangular wave control mode, based on the target operating point (torque command Tm * and rotation speed Nm) of the motor 22. Any one of these is controlled as the control mode Md. Here, the sine wave PWM control mode is a control mode for controlling the inverter 24 so that a pseudo three-phase AC voltage is applied (supplied) to the motor 22, and the overmodulation PWM control mode is an overmodulation voltage. This is a control mode for controlling the inverter 24 so as to be applied to the motor 22, and the rectangular wave control mode is a control mode for controlling the inverter 24 so that a rectangular wave voltage is applied to the motor 22. FIG. 2 is an explanatory diagram for explaining an example of the relationship between the rotational speed Nm of the motor 22, the torque command Tm *, and the control mode Md of the inverter 24. As shown in the figure, the control mode Md of the inverter 24 includes a sine wave PWM control mode, an overmodulation PWM control mode, and a rectangular wave control mode from the side where the rotational speed Nm and the torque command Tm * of the motor 22 are small to the large side. It is determined to be.

  In the sine wave PWM control mode and the overmodulation PWM control mode, the control device 50 first assumes that the total sum of currents flowing in the phases (U phase, V phase, W phase) of the motor 22 is 0, and the current sensor 22u. , 22v and the electrical angle θe calculated based on the rotation angle θm of the rotor of the motor 22 detected by the rotation angle detection sensor 22a. Phase conversion of the phase currents Iu and Iv of the phase and V phase into the currents Id and Iq of the d-axis and q-axis (three-phase to two-phase conversion) is performed. Subsequently, current commands Id * and Iq * for the d and q axes in the dq coordinate system are set from the torque command Tm * and a predetermined map. Next, the d-axis and q-axis voltage commands Vd * and Dq are used as feedback terms based on the differences ΔId and ΔIq between the d-axis and q-axis current commands Id * and Iq * and the d-axis and q-axis currents Id and Iq, respectively. Vq * is calculated. Then, using the electrical angle θe of the motor 22, the d-axis and q-axis voltage commands Vd * and Vq * are coordinate-converted into the voltage commands Vu *, Vv * and Vw * for each phase (2-phase to 3-phase conversion). The PWM signals of the transistors T11 to T16 are generated by comparing the voltage commands Vu *, Vv *, Vw and the carrier voltage, and the switching control of the transistors T11 to T16 is performed using this PWM signal.

  Next, the operation of the driving device 20 of the embodiment configured as described above, particularly the operation when controlling the inverter 24 in the rectangular wave control mode will be described. FIG. 3 is a block diagram for explaining the control of the inverter 24 in the rectangular wave control mode in the drive device 20.

  In the rectangular wave control mode, as shown in the figure, the control device 50 first converts the U-phase and V-phase currents Iu and Iv to the d-axis by the same processing as in the sine wave PWM control mode and overmodulation PWM control mode. Coordinate conversion (three-phase to two-phase conversion) is performed on q-axis currents Id and Iq. Subsequently, the estimated output torque Trq1 estimated to be output from the motor 22 is set based on the d-axis and q-axis currents Id and Iq (estimated torque setting). Then, assuming that the sum of the currents flowing in the respective phases (U phase, V phase, W phase) of the motor 22 is 0, the estimated output torque Trq1, U phase, V phase phase currents Iu, Iv, voltage sensor 22b, A corrected torque Trq is set by correcting the estimated output torque Trq1 using the U-phase, V-phase, and W-phase phase voltages Vu, Vv, and Vw detected by 22c and 22d and the rotational speed Nm of the motor 22. The setting of the corrected torque Trq will be described later. Then, the corrected torque Trq is estimated as the output torque of the motor 22, and the voltage phase command θp * is calculated so that the difference between the corrected torque Trq and the torque command Tm * is canceled (rectangular control feedback calculation). When the voltage phase command θp * is calculated in this way, rectangular wave signals Vu, Vv, Vw are generated so that a rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22 (switching pattern output). Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 24, switching control of the transistors T11 to T16 of the inverter 24 is performed. The control device 50 repeatedly executes such processing every predetermined time T (for example, several msec).

  Next, the setting of the corrected torque Trq will be described. FIG. 4 is a flowchart showing an example of a corrected torque setting process routine executed by the control device 50. When this routine is executed, the control device 50 causes the U-phase and V-phase currents Iu and Iv and the U-phase, V-phase and W-phase phase voltages Vu, Vv and Vw, and the rotation speed Nm of the motor 22 to rotate. A process of inputting the angle θm is executed (step S100). As the phase currents Iu and Iv, those detected by the current sensors 22u and 22v are input. The phase voltages Vu, Vv, and Vw are those detected by the voltage sensors 22b, 22c, and 22d. The rotation speed Nm is input based on the rotation angle θm of the rotor of the motor 22. The rotation angle θm is input as detected by the rotation angle detection sensor 22a.

  Subsequently, the estimated output torque Trq1 estimated to be output from the motor 22 is set based on the d-axis and q-axis currents Id and Iq (step S110). This process is a process corresponding to the estimated torque setting described above. The estimated output torque Trq1 is set by determining the relationship between the currents Id and Iq of the d-axis and q-axis and the torque output from the motor 22 by experiment or analysis and storing them as a map. The torque corresponding to when the currents Id and Iq are given is set to the estimated output torque Trq1. FIG. 5 is an explanatory diagram showing the relationship between the d-axis and q-axis currents Id and Iq and the torque output from the motor 22.

  Next, the estimated output torque Trq2 is calculated using the following equation (1) (step S120). As shown in the equation (1), the estimated output torque Trq2 assumes that the sum of the currents flowing in the phases (U phase, V phase, W phase) of the motor 22 is 0, and the phase currents Iu, Iv, Iw (= 0−Iu−Iv), voltages Vu, Vv, Vw, and rotation speed Nm. The rotation speed Nm is calculated using the rotation angle θm detected by the rotation angle detection sensor 22a. In general, it is known that the difference between the rotational speed Nm and the actual rotational speed Nm of the motor 22 is not so large when an error due to a detection delay of the rotational angle detection sensor 22a occurs. Therefore, even when the rotation angle θm and the actual rotation angle deviate, the difference between the estimated output torque Trq2 and the torque output from the motor 22 is small.

  Trq2 = (Iu ・ Vu + Iv ・ Vv + Iw ・ Vw) / Nm (1)

  Then, torque average values Trq1_av and Trq2_av, which are average values of the estimated output torques Trq1 and Trq2, are calculated using the following equations (2) and (3) (step S130). In formulas (2) and (3), “Trq1_N” and “Trq2_N” are set or calculated in the processing of steps S110 and S120 when this routine is executed N times (N is a real number greater than or equal to 1). Estimated output torque Trq1, Trq2. The value Nth is calculated using the following equation (4). In Expression (4), “ωe” is a resonance frequency of torsional vibration of the drive system including the motor 32. Examples of the drive system include a drive system (motor, drive wheel, differential gear, etc.) connected to the drive shaft when the rotating shaft of the motor 32 is connected to the drive shaft of the vehicle. “N” is reset to 0 when the number of repetitions of this routine reaches the value Nth.

  Nth = (1 / ωe) / T (4)

  Subsequently, it is determined whether or not the fluctuation amount ΔNm of the rotational speed Nm2 exceeds the predetermined fluctuation amount dNmref (step S140). The fluctuation amount ΔNm is calculated by subtracting the rotation speed Nm input in the process of step S100 when this routine was executed last time from the rotation speed Nm of the motor 22 input in the process of step S100. The predetermined fluctuation amount dNmref is a threshold value for determining whether or not the rotational speed Nm of the motor 22 has fluctuated due to disturbance.

  Here, the reason why the rotational speed Nm of the motor 22 varies due to disturbance will be described. FIG. 6 is an explanatory diagram illustrating an example of a time change between the estimated output torque Trq1 and the actual torque Tmr actually output from the motor 22 when the rotation speed Nm of the motor 22 varies due to disturbance. In the figure, the solid line is an example of the time change of the actual torque Tmr. A broken line is an example of a time change of the estimated output torque Trq1. When a delay occurs in the detection of the rotation angle θm of the motor 22 by the rotation angle detection sensor 22a, the estimated output torque Trq1 is delayed in phase with respect to the actual torque Tmr, as shown in FIG. For example, when the rotational speed Nm of the motor 22 changes, increasing, decreasing, and increasing, the estimated output torque Trq1 is calculated to be smaller than the actual torque Tmr when the rotational speed Nm of the motor 22 is increased. When the number Nm decreases, it is calculated to be larger than the actual torque Tmr. When the phase difference between the actual torque Tmr and the estimated output torque Trq1 increases to some extent, the control becomes oscillating and the fluctuation of the rotational speed of the motor 22 increases. The reason why the rotational speed Nm of the motor 22 fluctuates due to disturbance is based on these reasons.

  When it is determined in step S140 that the variation ΔNm is equal to or less than the predetermined variation dNmref, it is determined that the rotational speed Nm of the motor 22 does not vary due to disturbance, and the estimated output torque Trq1 is changed to the corrected torque Trq. After setting (step S150), this routine is finished. When such a corrected torque Trq is set, the corrected torque Trq is estimated as the output torque of the motor 22, and the voltage phase command θp * is calculated so that the difference between the corrected torque Trq and the torque command Tm * is canceled out. The rectangular wave signals Vu, Vv, and Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22. Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 24, switching control of the transistors T11 to T16 of the inverter 24 is performed. Thus, the current is set from the d-axis and q-axis currents Id and Iq calculated using the same state quantities (phase currents Iu and Iv and the rotation angle θm) as in the sine wave PWM control mode and the overmodulation PWM control mode. The estimated output Trq1 is set to the corrected torque Trq, the corrected torque Trq is estimated as the torque output from the motor 22, and the inverter 24 is controlled so that the sine wave PWM control mode and the overmodulation PWM control mode are set. The sudden change of the output torque from the motor 22 when switching the control mode with the rectangular wave control is suppressed.

  If it is determined in step S140 that the fluctuation amount ΔNm exceeds the predetermined fluctuation amount dNmref, it is determined that the rotational speed Nm of the motor 22 is fluctuating due to disturbance, and then the torque fluctuation amount ΔTrq1 is predetermined. It is determined whether or not the torque fluctuation amount dTrqref is exceeded (step S160). The torque fluctuation amount ΔTrq1 is calculated by subtracting the estimated output torque Trq1 set in step S110 when the routine was executed last time from the estimated output torque Trq1 set in step S110. The predetermined torque fluctuation amount dTrqref is a threshold value for determining whether or not the estimated output torque Trq1 is fluctuating.

  When it is determined in step S160 that the torque fluctuation amount ΔTrq1 is equal to or less than the predetermined torque fluctuation amount dTrqref, it is determined that the estimated output torque Trq1 has not fluctuated, and the estimated output torque Trq1 is set to the corrected torque Trq. (Step S150), and this routine ends. When such a corrected torque Trq is set, the corrected torque Trq is estimated as the output torque of the motor 22, and the voltage phase command θp * is calculated so that the difference between the corrected torque Trq and the torque command Tm * is canceled out. The rectangular wave signals Vu, Vv, and Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22. Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 24, switching control of the transistors T11 to T16 of the inverter 24 is performed. By such processing, a sudden change in the output torque from the motor 22 when the control mode is switched between the sine wave PWM control mode or the overmodulation PWM control mode and the rectangular wave control is suppressed.

  When it is determined in step S160 that the torque fluctuation amount ΔTrq1 exceeds the predetermined torque fluctuation amount dTrqref, the torque fluctuation amount ΔTrq2 is calculated by subtracting the torque average value Trq_2 from the estimated output torque Trq2 (step S170). A value obtained by adding the torque fluctuation amount ΔTrq2 to the average value Trq_1, that is, a value obtained by correcting the torque average value Trq_1 with the torque fluctuation amount ΔTrq2 is set as the corrected torque Trq (step S180), and this routine ends. When the corrected torque Trq is set in this manner, the corrected torque Trq is estimated as the output torque of the motor 22, and the voltage phase command θp * is calculated so that the difference between the corrected torque Trq and the torque command Tm * is canceled out. The rectangular wave signals Vu, Vv, and Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22. Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 24, switching control of the transistors T11 to T16 of the inverter 24 is performed. The torque average value Trq_1 calculated using the estimated output torque Trq_1 calculated using the same state quantities (phase currents Iu, Iv and rotation angle θm) as in the sine wave PWM control mode and overmodulation PWM control mode When the control mode is switched between the sine wave PWM control mode and the overmodulation PWM control mode and the rectangular wave control because the corrected torque Trq is set with the corrected value by the amount ΔTrq2, that is, the torque average value Trq_1 as the base value. A sudden change in the output torque from the motor 22 can be suppressed. Further, since the fluctuation of the estimated output torque Trq2 when the rotation angle θm deviates from the actual rotation angle is small, the torque fluctuation amount ΔTrq2 is a value reflecting the fluctuation of the torque actually output from the motor 22. It is believed that there is. In the process of step S180, the torque average value Trq_1 added with the torque fluctuation amount ΔTrq2, that is, the torque average value Trq_1 corrected by the torque fluctuation amount ΔTrq2 is set as the corrected torque Trq. Thus, the actual torque Tmr actually output from the motor 22 can be made closer.

  FIG. 7 shows the voltage phase command θp * when the estimated output torque Trq1 is subjected to the rectangular control feedback calculation using the corrected torque Trq, and the rectangular control feedback calculation using the actually output actual torque Tr as the corrected torque Trq. It is explanatory drawing which shows an example of a time change with voltage phase command (theta) p * (ideal voltage phase command (theta) pr). In the figure, the solid line is an example of the time change of the ideal voltage phase command θp *. A broken line is an example of a voltage phase command θp * when a rectangular control feedback calculation is performed using the estimated output torque Trq1 as the corrected torque Trq. As shown in FIG. 6, when a rectangular control feedback calculation is performed using the estimated output torque Trq1 as the corrected torque Trq, the voltage phase command θp * deviates from the ideal voltage phase command θpr. In the embodiment, the voltage phase command θp * can be brought closer to the ideal voltage phase command θpr by making the correction word torque Trq closer to the actual torque Tmr. Thereby, the fluctuation | variation of the output torque of the motor 22 by disturbance can be suppressed.

  According to the driving device 20 of the embodiment described above, when the inverter 24 is controlled in the rectangular wave control mode, the torque average is calculated using the currents Iu, Iv, Iw of each phase of the motor 22 and the rotation angle θm of the motor 22. The value Trq1_av is calculated, and the torque fluctuation amount ΔTrq2 of the motor 22 is calculated using the currents Iu, Iv, Iw of each phase of the motor 22, the voltages Vu, Vv, Vw of each phase of the motor 22 and the rotational speed Nm of the motor 22. The torque calculated by correcting the torque average value Trq1_av with the torque fluctuation amount ΔTrq2 is estimated as the output torque of the motor 22, and the inverter 34 is controlled so that the motor 22 is driven with the target torque Tm * using the estimated output torque. This suppresses sudden changes in output torque when switching the control mode between the rectangular wave control mode and another control mode, and It is possible to suppress variations in output torque of the motor 22 by.

  In the driving device 20 of the embodiment, whether or not the fluctuation amount ΔNm of the rotational speed Nm2 exceeds the predetermined fluctuation amount dNmref or whether the torque fluctuation amount ΔTrq1 exceeds the predetermined torque fluctuation amount dTrqref in the processes of steps S140 and S160. However, the processing in steps S170 and S180 may be executed after the processing in step S130 without executing the processing in steps S140 and S160 and the processing in step S150.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the inverter 24 corresponds to an “inverter”, and the control device 50 corresponds to a “control device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the interpretation of the invention described in the column of means for solving the problem should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problem. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the motor drive manufacturing industry.

  20 drive device, 22 motor, 22a rotation angle detection sensor, 22u, 22v, 26b current sensor, 24 inverter, 26 battery, 22b, 22c, 22d, 26a voltage sensor, 50 control device, D11-D16 diode, T11-T16 transistor .

Claims (1)

An inverter that drives the motor;
A control device for controlling the inverter in a plurality of control modes including a rectangular wave control mode so that the motor is driven with a target torque;
A motor drive device comprising:
The control device, when controlling the inverter in the rectangular wave control mode, calculates an average torque value of the motor using a current of each phase of the motor and a rotation angle of the motor, and each phase of the motor. The torque fluctuation amount of the motor is calculated using the current of the motor, the voltage of each phase of the motor, and the rotation speed of the motor, and the torque obtained by correcting the torque average value with the torque fluctuation amount is calculated as the output torque of the motor. Controlling the inverter so that the motor is driven with the target torque using the estimated output torque,
Motor drive device.

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