JP6696456B2 - Motor drive - Google Patents

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 a motor drive device of this type, one provided with an inverter for driving a motor has been proposed (for example, refer to Patent Document 1). In this device, the inverter is controlled in a plurality of control modes including a rectangular wave control mode so that the motor is driven with a target torque. Then, 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 output torque of the motor 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 zero.

JP, 2007-159368, A

  In the above-mentioned motor drive device, when controlling the inverter in the rectangular wave control mode, if the rotation speed of the motor fluctuates due to disturbance, the estimated value of the output torque of the motor will have an error due to the detection delay of the rotation angle of the motor. May occur. As a method of suppressing the occurrence of such an error, a method of estimating the output torque of the motor without using the rotation angle of the motor can be considered. However, generally, in the 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 the phase currents 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 suddenly changes when the control mode is switched between the rectangular wave control mode and another control mode.

  The motor drive device of the present invention mainly suppresses a sudden change in the output torque when switching the control mode between the rectangular wave control mode and another control mode, and also suppresses a fluctuation in the output torque of the motor due to disturbance. To aim.

  The motor drive device of the present invention employs the following means in order to achieve the above-mentioned main object.

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 at a target torque,
A motor drive device comprising:
When controlling the inverter in the rectangular wave control mode, the control device calculates a torque average value of the motor by using a current of each phase of the motor and a rotation angle of the motor to calculate each phase of the motor. Of the motor, the voltage of each phase of the motor, and the rotation speed of the motor are used to calculate the torque fluctuation amount of the motor, and the torque obtained by correcting the torque average value with the torque fluctuation amount is defined as the output torque of the motor. Estimating and controlling the inverter so that the motor is driven at the target torque using the estimated output torque,
That is the summary.

  In the motor drive device of the present invention, when controlling the inverter in the rectangular wave control mode, the average torque value of the motor 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. Calculate the amount of torque fluctuation of the motor using the voltage of each phase of the motor and the number of rotations of the motor, and estimate the torque obtained by correcting the torque average value with the amount of torque fluctuation as the output torque of the motor. It is used to control the inverter so that the motor drives at the target torque. Generally, in a control mode different from the rectangular wave control mode, the estimated value of the torque output from the motor is calculated using the current of each phase of the motor and the rotation angle of the motor, and the inverter is calculated using the calculated estimated value. To control. Therefore, in the rectangular wave control mode, when the output torque of the motor is estimated by using a state quantity different from that of the other control modes and the inverter is controlled, the square wave control mode and the other control modes are different due to the detection error of the state quantity. The torque actually output from the motor may suddenly change when the control mode is switched between them. In the motor drive device of the present invention, in the rectangular wave control mode, the same state quantity as in the other control modes, that is, the current of each phase of the motor and the rotation angle of the motor are used to calculate the torque average value of the motor, The torque fluctuation amount of the motor is calculated using the current of each phase, 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 estimated as the output torque of the motor. The inverter is controlled so that the motor is driven at the target torque by using the estimated output torque, thus suppressing abrupt changes in the output torque from the motor when switching the control mode between the rectangular wave control mode and other control modes. can do. Further, if an error occurs in the detected rotation angle 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 a small effect even if an error occurs in the detected rotation angle. Therefore, by estimating the torque obtained by correcting the average torque value with the torque fluctuation amount that is less affected by the error of the rotation angle as the output torque of the motor, fluctuations in the rotation speed of the motor occur due to disturbance, and the rotation angle of the motor can be detected. Even when a delay occurs, it is possible to suppress the deviation between the estimated output torque of the motor and the torque actually output from the motor. Since the inverter is controlled using the motor output torque thus estimated, it is possible to suppress fluctuations in the motor output torque due to disturbance. As a result, it is possible to suppress a sudden change in the output torque when switching the control mode between the rectangular wave control mode and another control mode, and also suppress a fluctuation in the output torque of the motor due to disturbance.

  In the motor drive device of the present invention, the control device controls the inverter in the rectangular wave control mode, and when the variation amount of the rotation speed of the motor is equal to or more than a predetermined variation amount, the torque average value. Is calculated, the torque fluctuation amount is calculated, the torque obtained by correcting the torque average value with the torque fluctuation amount is estimated as the output torque of the motor, and the estimated output torque is used by the motor to obtain the target torque. The inverter may be controlled to drive. Here, the “predetermined variation amount” is a threshold value for determining whether or not the rotation speed of the motor has changed due to disturbance. This makes it possible to suppress fluctuations in the output torque of the motor when the rotation speed of the motor fluctuates due to disturbance.

  Further, in the motor drive device of the present invention, the control device, when controlling the inverter in the rectangular wave control mode, has a fluctuation amount of the rotation speed of the motor of a predetermined fluctuation amount or more, and 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 more 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 with the torque fluctuation amount may be estimated as an output torque of the motor, and the inverter may be controlled so that the motor is driven at the target torque by using the estimated output torque. .. Here, the “predetermined torque fluctuation amount” is a threshold value for determining whether or not the estimated output torque actually fluctuates. By doing this, when the rotation speed of the motor is fluctuating due to the disturbance and the estimated output torque is fluctuating, that is, when the rotation speed of the motor is fluctuating due to the disturbance, the estimated output torque fluctuates. The fluctuation of the output torque of the motor can be suppressed during the operation.

  Further, in the motor drive device of the present invention, the plurality of control modes may include the rectangular wave control mode and the PWM control mode. In this case, in the PWM control mode, the inverter may be controlled using the d-axis current and the q-axis current calculated using the currents of the respective phases 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 the relationship between the rotation speed Nm of the motor 22, the torque command Tm *, and the control mode Md of the inverter 24. In drive device 20, it is a block diagram for explaining control of an inverter 24 in a rectangular wave control mode. 7 is a flowchart showing an example of a corrected torque setting processing routine executed by the control device 50. It is explanatory drawing which shows the relationship between the electric currents Id and Iq of d-axis and q-axis, and the torque output from the motor 22. 7 is an explanatory diagram showing an example of a temporal change between an estimated output torque Trq1 and a real torque Tmr actually output from the motor 22 when the rotation speed Nm of the motor 22 changes due to a disturbance. FIG. The voltage phase command θp * when the estimated output torque Trq1 is calculated as the corrected torque Trq by the rectangular control feedback, and the voltage phase command θp when the actually output actual torque Tr is calculated as the corrected torque Trq by the rectangular control feedback. It is explanatory drawing which shows an example of the time change of * (ideal voltage phase command (theta) pr) and.

  Next, modes for carrying out the present invention will be described using examples.

  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 of the embodiment is mounted on a vehicle, for example, and is configured as a device that drives a drive shaft that is connected to an axle that is connected to drive wheels 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 the battery 26. The inverter 24 has six transistors T11 to T16 and six diodes D11 to D16. Two transistors T11 to T16 are arranged in pairs so that they are on the source side and the sink side with respect to the positive bus and the negative bus of the power line from the battery 26, respectively. The six diodes D11 to D16 are connected in parallel in reverse directions to the transistors T11 to T16, respectively. Each of the three-phase coils (U-phase, V-phase, W-phase) of the motor 22 is connected to each of the connection points of the paired transistors of the transistors T11 to T16. Therefore, when a voltage is applied to the inverter 24, the controller 50 adjusts the on-time ratio of the pair of transistors T11 to T16, so that a rotating magnetic field is formed in the three-phase coil and the motor 22 is driven. Is driven to rotate.

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

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

  Signals from various sensors are input to the control device 50 via input ports. As the signal input to the control device 50, for example, the rotation angle θm of the rotor of the motor 22 from a rotation angle detection sensor (for example, a resolver) 22a that detects the rotation position of the rotor of the motor 22, and each of the motor 22. The phase currents Iu, Iv flowing through the motor 22 from the current sensors 22u, 22v for detecting the current flowing through the phases, and the voltages Vu, Vv, Vw for the voltage sensors 22b, 22c, 22d for detecting the voltages of the respective phases 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 the output ports. The signal output from the control device 50 may be, for example, a switching control signal to the transistors T11 to T16 of the inverter 24. 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. Further, the control device 50 calculates the charge ratio SOC of the battery 26 based on the integrated value of the current Ib of the battery 26 from the current sensor 26b. Here, the charge ratio SOC is the ratio of the capacity of the 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 controls the switching 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, the sine wave PWM (pulse width modulation) control mode, the overmodulation PWM control mode, and the rectangular wave control mode are used based on the target operating point (torque command Tm * and rotation speed Nm) of the motor 22. Any one of them 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 for the overmodulation voltage. The control mode controls the inverter 24 so as to be applied to the motor 22, and the rectangular wave control mode controls the inverter 24 so that the rectangular wave voltage is applied to the motor 22. FIG. 2 is an explanatory diagram for explaining an example of the relationship between the rotation 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 rotation speed Nm of the motor 22 and the torque command Tm * are small to the side where the rotation speed Nm is small. Is determined to be.

  In the sine wave PWM control mode and the overmodulation PWM control mode, the control device 50 first determines that the total sum of the currents flowing in the respective 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. The phase currents Iu and Iv of the phase and V phase are coordinate-converted (three-phase to two-phase conversion) into currents Id and Iq of the d-axis and the q-axis. Then, the d-axis and q-axis current commands Id * and Iq * in the dq coordinate system are set from the torque command Tm * and a predetermined map. Next, as a feedback term based on the differences ΔId, ΔIq between the d-axis and q-axis current commands Id *, Iq * and the d-axis, q-axis currents Id, Iq, the d-axis and q-axis voltage commands Vd *, Calculate Vq *. Then, using the electrical angle θe of the motor 22, the voltage commands Vd *, Vq * for the d-axis and the q-axis are coordinate-converted (2-phase-3 phase conversion) into the voltage commands Vu *, Vv *, Vw * for each phase. The PWM signals of the transistors T11 to T16 are generated by comparing the voltage commands Vu *, Vv *, Vw with the carrier voltage, and the switching control of the transistors T11 to T16 is performed using the PWM signal.

  Next, the operation of the driving device 20 of the embodiment thus configured, 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 performs the same processing as in the sine wave PWM control mode and the overmodulation PWM control mode to set the phase currents Iu and Iv of the U phase and V phase to the d axis, Coordinate conversion (3 phase-2 phase conversion) is performed on the currents Id and Iq of the q axis. Then, 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 and the phase currents Iu, Iv of the U phase and V phase, the voltage sensor 22b, The corrected output torque Trq is set by correcting the estimated output torque Trq1 using the phase voltages Vu, Vv, Vw of the U phase, V phase, W phase detected by 22c, 22d and the rotation 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 manner, the rectangular wave signals Vu, Vv, Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22 (switching pattern output). Then, by outputting 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 processing 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 voltage Vu, Vv, and Vw, the rotation speed Nm of the motor 22, and the rotation speed. A process of inputting the angle θm is executed (step S100). The phase currents Iu and Iv are input as those detected by the current sensors 22u and 22v. As the phase voltages Vu, Vv, Vw, those detected by the voltage sensors 22b, 22c, 22d are input. The number of rotations Nm is input as a value calculated based on the rotation angle θm of the rotor of the motor 22. The rotation angle θm is the one detected by the rotation angle detection sensor 22a.

  Then, 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 above-described estimated torque setting. To set the estimated output torque Trq1, the relationship between the d-axis and q-axis currents Id and Iq and the torque output from the motor 22 is determined by experiments or analysis and stored as a map. The torque corresponding to the given currents Id and Iq is set as 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). The estimated output torque Trq2 is obtained by assuming that the sum of the currents flowing in the respective phases (U phase, V phase, W phase) of the motor 22 is 0, as shown in the equation (1), the phase currents Iu, Iv, Iw. (= 0-Iu-Iv), the voltages Vu, Vv, Vw, and the rotation speed Nm. The rotation speed Nm is calculated using the rotation angle θm detected by the rotation angle detection sensor 22a. It is generally known that the difference between the rotation speed Nm and the actual rotation speed Nm of the motor 22 is not so large when an error occurs due to the detection delay of the rotation angle detection sensor 22a. Therefore, even when the rotation angle θm deviates from the actual rotation angle, the deviation 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, the torque average values Trq1_av, Trq2_av, which are the average values of the estimated output torques Trq1, Trq2, are calculated using the following equations (2), (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 the present routine is executed N times (N is a real number of 1 or more). The estimated output torques Trq1 and Trq2. Further, the value Nth is calculated using the following equation (4). In Expression (4), “ωe” is the resonance frequency of the torsional vibration of the drive system including the motor 32. Examples of the drive system include a drive system (motor, drive wheels, differential gear, etc.) connected to the drive shaft when the rotation shaft of the motor 32 is connected to the drive shaft of the vehicle. It should be noted that "N" is reset to the value 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 rotation 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 processing of step S100 when the routine was last executed from the rotation speed Nm of the motor 22 input in the processing of step S100. The predetermined variation amount dNmref is a threshold value for determining whether or not the rotation speed Nm of the motor 22 has changed due to disturbance.

  Here, the reason why the rotation speed Nm of the motor 22 changes due to disturbance will be described. FIG. 6 is an explanatory diagram showing an example of a temporal 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 changes due to disturbance. In the figure, the solid line is an example of the change over time of the actual torque Tmr. The broken line is an example of the temporal change of the estimated output torque Trq1. When the detection of the rotation angle θm of the motor 22 by the rotation angle detection sensor 22a is delayed, the estimated output torque Trq1 is delayed in phase with respect to the actual torque Tmr, as shown in FIG. For example, when the rotation speed Nm of the motor 22 increases, decreases, or increases, the estimated output torque Trq1 is calculated smaller than the actual torque Tmr when the rotation speed Nm of the motor 22 increases, and the rotation speed of the motor 22 increases. When the number Nm decreases, it is calculated larger than the actual torque Tmr. When the phase difference between the actual torque Tmr and the estimated output torque Trq1 becomes large to some extent, the control becomes oscillating, and the fluctuation of the rotation speed of the motor 22 becomes large. This is the reason why the rotation speed Nm of the motor 22 changes due to disturbance.

  When it is determined in step S140 that the variation amount ΔNm is equal to or less than the predetermined variation amount dNmref, it is determined that the rotation speed Nm of the motor 22 has not changed due to disturbance, and the estimated output torque Trq1 is set to the corrected torque Trq. After setting (step S150), this routine is finished. When such 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. , Rectangular wave signals Vu, Vv, Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22. Then, by outputting 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. In this way, it 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 rotation angle θm) as in the sine wave PWM control mode and 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, whereby the sine wave PWM control mode or the overmodulation PWM control mode is set. The sudden change of the output torque from the motor 22 when the control mode is switched between the rectangular wave control and the rectangular wave control is suppressed.

  When it is determined in the process of step S140 that the fluctuation amount ΔNm exceeds the predetermined fluctuation amount dNmref, it is determined that the rotation speed Nm of the motor 22 is fluctuating due to disturbance, and subsequently, 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 the process of step S110 when the present routine was last executed from the estimated output torque Trq1 set in the process of step S110. The predetermined torque fluctuation amount dTrqref is a threshold value for determining whether the estimated output torque Trq1 is fluctuating.

  When it is determined in step S160 that the torque fluctuation amount ΔTrq1 is less than or equal to the predetermined torque fluctuation amount dTrqref, it is determined that the estimated output torque Trq1 has not changed, and the estimated output torque Trq1 is set to the corrected torque Trq. (Step S150), this routine is ended. When such 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. , Rectangular wave signals Vu, Vv, Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22. Then, by outputting 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, abrupt changes 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 are 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), and the torque fluctuation amount ΔTrq2 is calculated. The value obtained by adding the torque fluctuation amount ΔTrq2 to the average value Trq_1, that is, the value obtained by correcting the torque average value Trq_1 by the torque fluctuation amount ΔTrq2 is set as the corrected torque Trq (step S180), and this routine is ended. When the corrected torque Trq is set in this way, 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 wave signals Vu, Vv, Vw are generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 22. Then, by outputting 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 Trq1 calculated using the same state quantities (phase currents Iu, Iv and rotation angle θm) as in the sine wave PWM control mode or overmodulation PWM control mode is used as the torque fluctuation. When the control mode is switched between the sine wave PWM control mode or the overmodulation PWM control mode and the rectangular wave control, the value corrected by the amount ΔTrq2, that is, the torque average value Trq_1 is set as the corrected torque Trq with the base value. The 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 and the actual rotation angle deviate is small, the torque fluctuation amount ΔTrq2 is a value that reflects the fluctuation of the torque actually output from the motor 22. It is believed that there is. In the process of step S180, a value obtained by adding the torque fluctuation amount ΔTrq2 to the torque 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. The actual torque Tmr actually output from the motor 22 can be brought closer.

  FIG. 7 shows the voltage phase command θp * when the estimated output torque Trq1 is calculated as the corrected torque Trq by the rectangular control feedback calculation, and the actual output torque Tr that is actually output as the corrected torque Trq by the rectangular control feedback calculation. It is explanatory drawing which shows an example of the time change of voltage phase command (theta) p * (ideal voltage phase command (theta) pr). In the figure, the solid line is an example of the change over time of the ideal voltage phase command θp *. The broken line is an example of the voltage phase command θp * when the rectangular control feedback calculation is performed with the estimated output torque Trq1 as the corrected torque Trq. As shown in FIG. 6, when the estimated output torque Trq1 is used as the corrected torque Trq to perform the rectangular control feedback calculation, the voltage phase command θp * and the ideal voltage phase command θpr deviate. In the embodiment, the voltage phase command θp * can be brought closer to the ideal voltage phase command θpr by bringing the correction word torque Trq closer to the actual torque Tmr. As a result, fluctuations in the output torque of the motor 22 due to disturbance can be suppressed.

  According to the drive device 20 of the embodiment described above, when controlling the inverter 24 in the rectangular wave control mode, the torque average is calculated using the currents Iu, Iv, Iw of the respective phases 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 the respective phases of the motor 22, the voltages Vu, Vv, Vw of the respective phases of the motor 22, and the rotation speed Nm of the motor 22. A torque obtained by calculating and 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. As a result, it is possible to suppress a sudden change in the output torque when the control mode is switched between the rectangular wave control mode and another control mode, and to suppress a change in the output torque of the motor 22 due to disturbance.

  In the drive device 20 of the embodiment, whether or not the variation amount ΔNm of the rotation speed Nm2 exceeds the predetermined variation amount dNmref or whether the torque variation amount ΔTrq1 exceeds the predetermined torque variation amount dTrqref in the processes of steps S140 and S160. Although it is determined whether or not the processing of steps S140 and S160 and the processing of step S150 are not executed, the processing of steps S170 and S180 may be executed after the processing of step S130.

  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 will be described. In the embodiment, the inverter 24 corresponds to the “inverter” and the control device 50 corresponds to the “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 section of means for solving the problem. This is an example for specifically explaining the mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

  Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

  INDUSTRIAL APPLICABILITY The present invention can be used in the manufacturing industry of motor drive devices.

  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 to D16 diode, T11 to 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 at a target torque,
A motor drive device comprising:
When controlling the inverter in the rectangular wave control mode, the control device calculates a torque average value of the motor by using a current of each phase of the motor and a rotation angle of the motor to calculate each phase of the motor. Of the motor, the voltage of each phase of the motor, and the rotation speed of the motor are used to calculate the torque fluctuation amount of the motor, and the torque obtained by correcting the torque average value with the torque fluctuation amount is defined as the output torque of the motor. Estimating and controlling the inverter so that the motor is driven at the target torque using the estimated output torque,
Motor drive device.

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