JP2018143055A - Motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variation in output torque of a motor due to disturbance, while preventing rapid change in the output torque of the motor when switching between a rectangular-wave control mode and another control mode.SOLUTION: When an inverter is controlled in a rectangular-wave control mode, an average value of torque outputted from a motor is calculated based on a current in each phase of the motor as well as a rotational angle of the motor detected by a rotational angle detection sensor. Then, a torque variation amount of the motor is calculated with the use of a rotational speed of the motor calculated based on input/output power inputted into/outputted from a power storage device as well as the rotational angle detected by the rotational angle detection sensor. Output torque of the motor is estimated by using the average value and the torque variation amount. With the use of the output torque thus estimated, the inverter is controlled such that it may be driven at target 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, a rotation angle detection sensor, and a control device.

  2. Description of the Related Art Conventionally, as this type of motor drive device, a device including an inverter that drives a motor and exchanges electric power with a battery, and a rotation angle detection sensor that detects a rotation angle of the motor has been proposed (for example, 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 the inverter is controlled 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 detected by the rotation angle detection sensor, and the calculated d The output torque of the motor is estimated using the shaft current, the q-axis current, and the torque 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 controlling the inverter in the rectangular wave control mode, if the rotation speed of the motor changes due to disturbance, the phase of the estimated value of the output torque of the motor is actually detected due to the detection delay of the rotation angle detection sensor. The phase of the actual torque output from the motor may deviate greatly. If the voltage phase of the rectangular wave voltage is adjusted so that the difference between the estimated value of the output torque and the torque command is 0 while the phase of the estimated value of the output torque and the phase of the actual torque are greatly shifted, the control response Becomes vibration, and fluctuations in the cycle shorter than the above-described changes occur in the rotation speed and output torque of the motor. As a technique for suppressing such fluctuations, a technique for estimating the motor output torque from fluctuations in battery power input / output to / from the battery without using the detection force from the rotation angle detection sensor is conceivable. However, in general, in another control mode different from the rectangular wave control mode, the inverter is controlled using a d-axis current and a q-axis current calculated using each phase current of the motor and the rotation angle of the motor as state quantities. Therefore, when the output torque of the motor is estimated using the battery power that is a state quantity different from that in the other control modes in the rectangular wave control mode, the estimated value of the motor output torque is different from that in the rectangular wave control mode. The value differs depending on the control mode. Therefore, when the control mode is switched between the rectangular wave control mode and another control mode, the output torque from the motor changes suddenly.

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

  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 and exchanges power with the power storage device;
A rotation angle detection sensor for detecting a rotation angle of 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:
When the control device controls the inverter in the rectangular wave control mode, it is output from the motor using the current of each phase of the motor and the rotation angle of the motor detected by the rotation angle detection sensor. The average value of the torque is calculated, and the input / output power input / output to / from the power storage device and the rotation speed of the motor calculated using the rotation angle detected by the rotation angle detection sensor are used. A torque fluctuation amount is calculated, an output torque of the motor is estimated using the average value and the torque fluctuation amount, and the inverter is driven so that the motor is driven with the target torque using the estimated output torque. Control,
This is the gist.

  In the motor driving device of the present invention, when the inverter is controlled in the rectangular wave control mode, the torque output from the motor using the current of each phase of the motor and the rotation angle of the motor detected by the rotation angle detection sensor. The motor torque fluctuation amount is calculated using the input / output power input / output to / from the power storage device and the motor rotation speed calculated using the rotation angle detected by the rotation angle detection sensor. Then, the output torque of the motor is estimated using the average value and the torque fluctuation amount, and the inverter is controlled using the estimated output torque so that the motor is driven with the target torque. When controlling the inverter in the rectangular wave control mode, if the motor rotation speed varies due to disturbance, an error occurs in the rotation angle of the motor detected by the rotation angle detection sensor due to the detection delay of the rotation angle detection sensor. The rotational speed of the motor is calculated using the rotational angle detected by the rotational angle detection sensor, but the error of the detected rotational angle has little influence on the calculated rotational speed of the motor. Therefore, even if an error occurs in the rotation angle detected by the rotation angle detection sensor, the calculation is performed using the input / output power and the rotation speed of the motor calculated using the rotation angle detected by the rotation angle detection sensor. The torque fluctuation amount of the motor is close to the actual torque fluctuation amount of the motor. Therefore, the estimated output is obtained by estimating the output torque of the motor using the calculated average value of torque and the amount of torque fluctuation, and controlling the inverter so that the motor is driven at the target torque using the estimated output torque. The shift in phase between the torque phase and the torque actually output from the motor can be suppressed, and the control response when controlling the inverter can be suppressed from becoming vibrational. Thereby, the fluctuation | variation of the output torque of the motor resulting from a disturbance can be suppressed. In general, in a control mode different from the rectangular wave control mode, the estimated value of torque output from the motor is calculated using the current of each phase of the motor as the state quantity and the rotation angle of the motor detected by the rotation angle detection sensor. Then, the inverter is controlled using the calculated estimated value. When controlling the inverter in the rectangular wave control mode, the average value of the torque output from the motor is obtained by detecting the current of each phase of the motor, which is the same state quantity as in the other control modes, and the rotation angle detection sensor. Therefore, a sudden change in output torque from the motor when the control mode is switched between the rectangular wave control mode and another control mode can be suppressed. Therefore, when the control mode is switched between the rectangular wave control mode and another control mode, it is possible to suppress a sudden change in the output torque of the motor and to suppress a fluctuation in the output torque of the motor due to a disturbance. .

  In such a motor drive device of the present invention, when the control device controls the inverter in the rectangular wave control mode, when the calculated fluctuation amount of the rotation speed of the motor is a predetermined fluctuation amount or more, An average value is calculated, the torque fluctuation amount is calculated, a torque obtained by adding the torque fluctuation amount to the average value is estimated as an output torque of the motor, and the motor uses the estimated output torque to cause the motor to output the target torque. The inverter may be controlled so as to be driven by 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 detected by the rotation angle detection sensor is equal to or larger than a predetermined torque fluctuation amount, the torque average value is calculated. The torque fluctuation amount is calculated, the torque obtained by adding the torque fluctuation amount to the torque average value is estimated as the output torque of the motor, and the motor is driven by the target torque using the estimated output torque. The inverter may be controlled. 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.

  In the motor drive device of the present invention, the inverter may exchange power with the power storage device via a boost converter.

  Further, in the motor drive device according to the present invention, the motor and the battery are mounted on a vehicle, the motor is connected to a drive shaft having a rotation shaft connected to the axle, and the control device performs the calculation. A second estimated output torque is calculated by dividing a value obtained by performing a band-pass filter process for extracting a frequency component within a resonance frequency band of the device connected to the drive shaft to the input / output power by the number of rotations of the motor. A value obtained by subtracting an average value of the second estimated output torque from the second estimated output torque may be calculated as the torque fluctuation amount.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 carrying 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 32, a torque command Tm *, and a control mode Md of an inverter 34. FIG. 4 is a block diagram for explaining control of inverter 34 in a rectangular wave control mode in electric vehicle 20. 5 is a flowchart showing an example of a corrected torque setting process routine executed by the electronic control unit 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 32. 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 32 is fluctuated by disturbance, and the actual torque Tmr actually output from the motor 32. Voltage phase command θp * when rectangular control feedback calculation is performed using estimated output torque Trq1 as corrected torque Trq, and voltage phase command θpr when rectangular control feedback calculation is performed using actual torque Tr actually output as corrected torque Trq It is explanatory drawing which shows 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 the configuration of an electric vehicle 20 equipped with a motor drive device as an embodiment of the present invention. The electric vehicle 20 according to the embodiment includes a motor 32, an inverter 34, a battery 36, a boost converter 40, and an electronic control unit 50, as illustrated.

  The motor 32 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 rotor of the motor 32 is connected to a drive shaft 26 that is coupled to the drive wheels 22a and 22b via a differential gear 24.

  Inverter 34 is connected to motor 32 and connected to boost converter 40 via high-voltage power line 42. The inverter 34 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 electrode bus and the negative electrode bus of the high voltage power line 42, 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 32 is connected to each connection point between the transistors T11 to T16 as a pair. Therefore, when a voltage is applied to the inverter 34, the electronic control unit 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 32 is rotationally driven. A smoothing capacitor 46 is attached to the positive and negative buses of the high voltage system power line 42.

  The battery 36 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the boost converter 40 via the low voltage system power line 44. A smoothing capacitor 48 is attached to the positive and negative buses of the low voltage system power line 44.

  Boost converter 40 is connected to high voltage power line 42 to which inverter 34 is connected and low voltage power line 44 to which battery 36 is connected. Boost converter 40 includes two transistors T31 and T32, two diodes D31 and D32, and a reactor L. The transistor T31 is connected to the positive bus of the high voltage system power line 42. The transistor T32 is connected to the transistor T31 and the negative buses of the high voltage system power line 42 and the low voltage system power line 44. The two diodes D31 and D32 are respectively connected in parallel to the transistors T31 and T32 in the reverse direction. The reactor L is connected to a connection point between the transistors T31 and T32 and a positive bus of the low voltage system power line 44. The step-up converter 40 adjusts the on-time ratio of the transistors T31 and T32 by the electronic control unit 50 to boost the power of the low voltage system power line 44 and supply it to the high voltage system power line 42. The power of the high voltage system power line 42 is stepped down and supplied to the low voltage system power line 44.

  The electronic control unit 50 is configured as a microprocessor centered on the CPU 52, and includes a ROM 54 for storing a processing program, a RAM 56 for temporarily storing data, and an input / output port in addition to the CPU 52.

  Signals from various sensors are input to the electronic control unit 50 via input ports. As a signal input to the electronic control unit 50, for example, a rotation angle detection sensor that detects the rotation angle (rotation position) of the rotor of the motor 32 (for example, a resolver and an R that converts a signal from the resolver into a digital value). (A known rotation angle detection sensor provided with a / D converter) a rotation angle θm of the rotor of the motor 32 from the motor 32a, and a phase flowing to the motor 32 from the current sensors 32u and 32v for detecting a current flowing in each phase of the motor 32. Currents Iu and Iv can be given. Moreover, the voltage Vb from the voltage sensor 36a attached between the terminals of the battery 36 and the current Ib from the current sensor 36b attached to the output terminal of the battery 36 can also be mentioned. Furthermore, the voltage VH of the capacitor 46 (high voltage system power line 42) from the voltage sensor 46a attached between the terminals of the capacitor 46, and the capacitor 48 (low voltage from the voltage sensor 48a attached between the terminals of the capacitor 48). The voltage VL of the system power line 44) can also be mentioned. In addition, the ignition signal from the ignition switch 60 and the shift position SP from the shift position sensor 62 that detects the operation position of the shift lever 61 can also be cited. Further, the accelerator opening Acc from the accelerator pedal position sensor 64 that detects the depression amount of the accelerator pedal 63, the brake pedal position BP from the brake pedal position sensor 66 that detects the depression amount of the brake pedal 65, and the vehicle speed sensor 68 The vehicle speed V can also be mentioned.

  Various control signals are output from the electronic control unit 50 through an output port. Examples of the signal output from the electronic control unit 50 include a switching control signal to the transistors T11 to T16 of the inverter 34 and a switching control signal to the transistors T31 and T32 of the boost converter 40. The electronic control unit 50 calculates the electrical angle θe and the rotational speed Nm of the motor 32 based on the rotational position θm of the rotor of the motor 32 from the rotational angle detection sensor 32a. Further, the electronic control unit 50 calculates the storage ratio SOC of the battery 36 based on the integrated value of the current Ib of the battery 36 from the current sensor 36b. Here, the storage ratio SOC is the ratio of the capacity of power that can be discharged from the battery 36 to the total capacity of the battery 36.

  In the electric vehicle 20 of the embodiment thus configured, the electronic control unit 50 performs the following traveling control. In the travel control, the required torque Td * required for the drive shaft 26 is set based on the accelerator opening Acc and the vehicle speed V, the set required torque Td * is set as the torque command Tm * of the motor 32, and the motor 32 Is controlled by the torque command Tm * to perform switching control of the transistors T11 to T16 of the inverter 34. Further, the target voltage VH * of the high voltage system power line 42 is set so that the motor 32 can be driven with the torque command Tm *, and the boost converter 40 is set so that the voltage VH of the high voltage system power line 42 becomes the target voltage VH *. The transistors T31 and T32 are controlled to be switched.

  Here, the control of the inverter 34 will be described. In the embodiment, for the inverter 34, 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 32. Any one of these is controlled as the control mode Md. Here, the sine wave PWM control mode is a control mode in which the inverter 34 is controlled so that a pseudo three-phase AC voltage is applied (supplied) to the motor 32. The overmodulation PWM control mode has an overmodulation voltage. The rectangular wave control mode is a control mode in which the inverter 34 is controlled so that a rectangular wave voltage is applied to the motor 32. FIG. 2 is an explanatory diagram for explaining an example of the relationship between the rotational speed Nm of the motor 32, the torque command Tm *, and the control mode Md of the inverter 34. As shown in the figure, the control mode Md of the inverter 34 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 of the motor 32 and the torque command Tm * 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 electronic control unit 50 first determines that the sum of currents flowing in the respective phases (U phase, V phase, W phase) of the motor 32 is 0, and is a current sensor. Using the phase currents Iu, Iv of the motor 32 detected by 22u, 22v and the electrical angle θe calculated based on the rotation angle θm of the rotor of the motor 32 detected by the rotation angle detection sensor 32a, U-phase and V-phase phase currents Iu and Iv are coordinate-converted into d-axis and q-axis currents Id and Iq (three-phase to two-phase conversion). 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 32, 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 electric vehicle 20 of the embodiment configured as described above, particularly the operation when controlling the inverter 34 in the rectangular wave control mode will be described. FIG. 3 is a block diagram for explaining the control of the inverter 34 in the rectangular wave control mode in the electric vehicle 20.

  In the rectangular wave control mode, as shown in the figure, the electronic control unit 50 first converts the U-phase and V-phase currents Iu and Iv into the d-axis by the same processing as in the sine wave PWM control mode and overmodulation PWM control mode. , And q-axis currents Id and Iq are converted into coordinates (three-phase to two-phase conversion). Subsequently, the estimated output torque Trq1 estimated to be output from the motor 32 is set based on the d-axis and q-axis currents Id and Iq (estimated output torque setting). Then, assuming that the sum of the currents flowing in the respective phases (U phase, V phase, W phase) of the motor 32 is 0, the estimated output torque Trq1 and the phases of the U phase and V phase detected by the current sensors 32u, 32b The corrected torque Trq is set using the currents Iu and Iv, the voltage Vb from the voltage sensor 36a, the current Ib from the current sensor 36b, and the rotational speed Nm of the motor 32. 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 32, 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 thus calculated, 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 32, and the generated rectangular wave signals Vu, Vv are generated. , Vw are output to the inverter 34 (switching pattern output). Then, switching control of the transistors T11 to T16 of the inverter 34 is performed using the waveform signals Vu, Vv, and Vw. The electronic control unit 50 executes such a series of processes every predetermined time Tc (for example, every 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 electronic control unit 50. When this routine is executed, the electronic control unit 50 inputs the U-phase and V-phase phase currents Iu and Iv, the voltage Vb and current Ib of the battery 36, the rotational speed Nm of the motor 32, and the rotational 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 voltage Vb is input as detected by a voltage sensor 36a attached between the terminals of the battery 36. The current Ib is input as detected by a current sensor 36b attached to the output terminal of the battery 36. As the rotation speed Nm, a value calculated based on the rotation angle θm of the rotor of the motor 32 is input. The rotation angle θm is input as detected by the rotation angle detection sensor 32a.

  Next, the estimated output torque Trq1 estimated to be output from the motor 32 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 output torque setting. The estimated output torque Trq1 is set by determining the relationship between the d-axis and q-axis currents Id and Iq and the torque output from the motor 32 by experiment or analysis and storing it 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 32.

  Subsequently, the processes of steps S120 to S150 are executed, and the average value (torque average value) Trq1_av of the torque actually output from the motor 32 and the fluctuation amount (torque fluctuation amount) ΔTrq2 from the torque average value Trq1_av are obtained. Calculate. The calculation of the torque fluctuation amount ΔTrq2 is performed using the battery power Pb and the rotational speed Nm of the motor 32. First, the battery power Pb input / output to / from the battery 36 is calculated (step S120). Battery power Pb is calculated by multiplying voltage Vb by current Ib.

  Subsequently, an estimated output torque Trq2, which is an estimated value of the torque output from the motor 32, is calculated using the battery power Pb and the rotation speed Nm of the motor 32 (step S130). The calculation of the estimated output torque Trq2 extracts only the resonance frequency component of the drive system (motor 32, drive wheels 22a, 22b, differential gear 24, etc.) connected to the drive shaft 26 from the frequency components included in the battery power Pb. Thus, the value Pb_fit obtained by subjecting the battery power Pb to bandpass processing is divided by the number of revolutions Nm of the motor 32 to calculate. The battery power Pb includes various frequency components such as switching frequency components of the inverter 34 and the boost converter 40. By setting the estimated output torque Trq2 using the value Pb_fit, only the component of the resonance frequency of the drive system connected to the drive shaft 26 can be extracted from the frequency components included in the battery power Pb. Here, since the battery power Pb is calculated without using the rotation angle θ detected by the rotation angle detection sensor 32a, the battery power Pb is not affected by the detection delay of the rotation angle detection sensor 32a. The rotation speed Nm is calculated using the rotation angle θm detected by the rotation angle detection sensor 32a. Even if a detection delay of the rotation angle detection sensor 32a occurs due to a change in the rotation speed of the motor 32 due to disturbance, It is known that the rotational speed Nm and the actual rotational speed of the motor 32 do not greatly deviate. Thus, the estimated output torque Trq2 is calculated using the battery power Pb that is not affected by the detection delay of the rotation angle detection sensor 32a and the rotation speed Nm that is less affected by the detection delay of the rotation angle detection sensor 32a. The estimated output torque Trq2 is a value that is less affected by the detection delay of the rotation angle detection sensor 32a.

  When the estimated output torque Trq2 is thus calculated, 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 (1) and (2) (step S140). In formulas (1) and (2), “Trq1_N” and “Trq2_N” are set or calculated in the processing of steps S110 and S130 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 (3). In Expression (3), “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 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) / Tc (3)

  Next, torque fluctuation amount ΔTrq2 is calculated by subtracting torque average value Trq_2 from estimated output torque Trq2 (step S150). Since the estimated output torque Trq2 is a value that is less affected by the detection delay of the rotation angle detection sensor 32a, the torque fluctuation amount ΔTrq2 is also a value that is less affected by the detection delay of the rotation angle detection sensor 32a.

  When the torque average value Trq1_av and the torque fluctuation amount ΔTrq2 are thus calculated, it is determined whether or not the fluctuation amount ΔNm of the rotational speed Nm2 exceeds the predetermined fluctuation amount dNmref (step S160). 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 32 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 32 is fluctuated due to disturbance, and is set to 50 rpm, 100 rpm, 150 rpm, or the like, for example.

  If it is determined in step S160 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 32 is not varying, and the estimated output torque Trq1 is set to the corrected torque Trq. (Step S180), 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 32, 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 32. Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 34, switching control of the transistors T11 to T16 of the inverter 34 is performed. Thus, estimation based on 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. By setting the output torque Trq1 to the corrected torque Trq, estimating the corrected torque Trq as the torque output from the motor 32, and controlling the inverter 34, the sine wave PWM control mode and the overmodulation PWM control mode are rectangular. The sudden change of the output torque from the motor 32 at the time of switching a control mode between wave control is suppressed.

  If it is determined in step S160 that the fluctuation amount ΔNm exceeds the predetermined fluctuation amount dNmref, it is determined that the rotational speed Nm of the motor 32 is fluctuating, and then the torque fluctuation amount ΔTrq1 is changed to the predetermined torque fluctuation. It is determined whether or not the amount dTrqref is exceeded (step S170). 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 torque actually output from the motor 32 is fluctuating.

  Here, the reason for determining whether or not the torque fluctuation amount ΔTrq1 exceeds the predetermined torque fluctuation amount dTrqref in the process of step S130 will be described. FIG. 6 is an explanatory diagram showing an example of a time change between the estimated output torque Trq1 and the actual torque Tmr actually output from the motor 32 when the rotation speed Nm of the motor 32 is changed 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. The rotation angle detection sensor 32a desirably has good responsiveness. However, if the responsiveness is too good, noise resistance is lowered, so that the responsiveness is slightly lowered. Therefore, when the rotation speed Nm of the motor 32 changes due to disturbance, a detection delay of the rotation angle θm of the motor 32 by the rotation angle detection sensor 32a occurs. When such a detection delay occurs, as shown in the figure, the phase of the estimated output torque Trq1 is delayed with respect to the phase of the actual torque Tmr. Therefore, the estimated output torque Trq1 is calculated smaller than the actual torque Tmr when the actual torque Tmr is increased and the rotation speed Nm of the motor 32 is increasing, and the actual torque Tmr is decreased and the rotation speed Nm of the motor 32 is decreased. When is reduced, it is calculated to be larger than the actual torque Tmr. In this way, with the phase difference between the actual torque Tmr and the estimated output torque Trq1, the estimated output torque Trq1 is set to the corrected torque Trq as it is, and the difference between the corrected torque Trq and the torque command Tm * is When the voltage phase command θp * is calculated so as to be canceled and the inverter 34 is controlled by the rectangular wave signals Vu, Vv, Vw generated so that the rectangular wave voltage based on the voltage phase command θp * is applied to the motor 32, the motor The torque actually output from the motor 32 increases or decreases (vibrates) with the torque in the vicinity of the torque command Tm1 *, and the rotational speed Nm of the motor 32 and the torque output from the motor 32 vary. The fluctuation in the rotational speed Nm of the motor 32 is caused by a factor different from the change in the rotational speed Nm of the motor 32 described above. In the embodiment, it is determined whether or not the torque actually output from the motor 32 is fluctuating by determining whether or not the torque fluctuation amount ΔTrq1 exceeds the predetermined fluctuation amount dNmref. For these reasons, it is determined whether or not the torque fluctuation amount ΔTrq1 exceeds the predetermined torque fluctuation amount dTrqref.

  When it is determined in step S170 that the torque fluctuation amount ΔTrq1 is equal to or smaller than the predetermined torque fluctuation amount dTrqref, the torque output actually output from the motor 32 is small, so the estimated output torque Trq1 is changed to the corrected torque Trq. The estimated output torque Trq1 is set to the corrected torque Trq (step S180), and this routine is terminated. When the corrected torque Trq is thus set, the corrected torque Trq is estimated as the output torque of the motor 32, 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 32. Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 34, switching control of the transistors T11 to T16 of the inverter 34 is performed. By such processing, a sudden change in the output torque from the motor 32 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.

  If it is determined in step S170 that the torque fluctuation amount ΔTrq1 exceeds the predetermined torque fluctuation amount dTrqref, it is determined that the fluctuation of the torque output from the motor 32 is large, and the torque average value Trq_av is obtained. A value obtained by adding the torque fluctuation amount ΔTrq2 is set as the corrected torque Trq (step S190), and this routine is finished. When the corrected torque Trq is thus set, the corrected torque Trq is estimated as the output torque of the motor 32, 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 32. Then, by switching the generated rectangular wave signals Vu, Vv, Vw to the inverter 34, switching control of the transistors T11 to T16 of the inverter 34 is performed. By such processing, the torque average value 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 and overmodulation PWM control mode. Since a value obtained by adding the torque fluctuation amount ΔTrq22 to Trq_1 is set as the corrected torque Trq, an estimated value of torque output from the motor 32 calculated from a state quantity different from the sine wave PWM control mode and the overmodulation PWM control mode ( For example, compared with the estimated output torque Trq2) estimated from the battery power Pb as the corrected torque Trq as it is, the control mode is changed between the sine wave PWM control mode and the overmodulation PWM control mode and the rectangular wave control. A sudden change in output torque from the motor 32 at the time of switching can be suppressed. Further, since the torque average value Trq_av plus the torque fluctuation amount ΔTrq2 that is less affected by the detection delay of the rotation angle detection sensor 32a is set as the corrected torque Trq, the corrected torque Trq is actually output from the motor 32 more. The actual torque Tmr can be brought close to.

  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 the time change of voltage phase instruction | command θpr. In the figure, the solid line is an example of the time change of the voltage phase command θpr. A broken line is an example of a time change of the voltage phase command θp *. As shown in FIG. 7, the voltage phase command θp * and the voltage phase command θpr are different. In the embodiment, the corrected torque Trq can be approximated to the actual torque Tmr, and therefore the voltage phase command θp * can be approximated to the voltage phase command θpr. Thereby, the fluctuation | variation of the output torque of the motor 32 by disturbance can be suppressed. Therefore, the vibration of the vehicle can be suppressed.

  According to the electric vehicle 20 of the embodiment described above, when the inverter 34 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 32 and the rotation angle θm of the motor 32. The value Trq_av is calculated, the torque fluctuation amount ΔTrq2 of the motor 32 is calculated using the battery power Pb and the rotational speed Nm of the motor 32, and the torque obtained by adding the torque fluctuation amount ΔTrq2 to the torque average value Trq_av is calculated as the output torque of the motor 32. And the inverter 34 is controlled so that the motor 32 is driven at the target torque Tm * using the estimated output torque, thereby switching the control mode between the rectangular wave control mode and another control mode. While suppressing the sudden change of output torque, the fluctuation | variation of the output torque of the motor 32 by disturbance can be suppressed.

  In the electric vehicle 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 S160 and S170. However, the processing of step S190 may be executed after the processing of step S150 is executed without executing the processing of steps S160 and S170 and the processing of step S180.

  In the electric vehicle 20 of the embodiment, the boost converter 40 is provided between the battery 36 and the inverter 34, but the boost converter 40 may not be provided.

  In the electric vehicle 20 of the embodiment, the battery 36 is used as the power storage device. However, any device may be used as long as it can store power, such as a capacitor.

  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 34 corresponds to an “inverter”, the rotation angle detection sensor 32 a corresponds to a “rotation angle detection sensor”, and the electronic control unit 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. That is, the interpretation of the invention described in the column of means for solving the problems 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 problems. 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 electric vehicle, 22a, 22b drive wheel, 24 differential gear, 26 drive shaft, 32 motor, 32a rotation angle detection sensor, 32u, 32v, 36b current sensor, 34 inverter, 36 battery, 36a, 46a, 48a voltage sensor, 40 Boost converter, 42 High voltage system power line, 44 Low voltage system power line, 46, 48 Capacitor, 50 Electronic control unit, 52 CPU, 54 ROM, 56 RAM, 60 Ignition switch, 61 Shift lever, 62 Shift position sensor, 63 Accelerator pedal, 64 Accelerator pedal position sensor, 65 Brake pedal, 66 Brake pedal position sensor, 68 Vehicle speed sensor, D11 to D16, D31, D32 Diode, L reactor, T11 to T1 , T31, T32 transistor.

Claims (1)

An inverter that drives the motor and exchanges power with the power storage device;
A rotation angle detection sensor for detecting a rotation angle of 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:
When the control device controls the inverter in the rectangular wave control mode, it is output from the motor using the current of each phase of the motor and the rotation angle of the motor detected by the rotation angle detection sensor. The average value of the torque is calculated, and the input / output power input / output to / from the power storage device and the rotation speed of the motor calculated using the rotation angle detected by the rotation angle detection sensor are used. A torque fluctuation amount is calculated, an output torque of the motor is estimated using the average value and the torque fluctuation amount, and the inverter is driven so that the motor is driven with the target torque using the estimated output torque. Control,
Motor drive device.

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