JP2013005618A - Inverter control device and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress motor torque fluctuation after the control mode is changed from rectangular wave control to overmodulation control.SOLUTION: When an inverter is controlled under overmodulation control, voltage commands Vd* and Vq* of a d-axis and a q-axis are set by current feedback control that uses a difference between currents Id, Iq and current commands Id*, Iq* of the d-axis and q-axis, control gains of proportional and integral terms, and an integral interval of the integral term. During the switching of the control mode between the rectangular wave control and overmodulation control, when the motor torque fluctuation is likely to increase due to the switching (i.e., a fluctuation-supposed state) (S110, S120), the gains of the proportional and integral terms are made larger and the integral interval of the integral term is made shorter (S140) than in a non fluctuation-supposed state.

Description

  The present invention relates to an inverter control device and a vehicle, and more specifically, includes an inverter control device that controls an inverter for driving a motor by any one of sine wave control, overmodulation control, and rectangular wave control, and such an inverter control device. Regarding vehicles.

  Conventionally, as this type of inverter control device, an inverter control method for driving an AC motor is changed from rectangular wave voltage control to PWM control (overmodulation PWM control) using a current phase calculated from a predetermined switching determination torque. ), When the absolute value of the torque deviation with respect to the torque command value is equal to or smaller than the predetermined value, the torque command value is used as a switching determination torque. When the absolute value of the torque deviation with respect to the torque command value is larger than the predetermined value, the torque command There has been proposed one that uses a value obtained by adding a predetermined value to a value as a switching determination torque (see, for example, Patent Document 1). In this inverter control device, the switching delay from the rectangular wave voltage control to the PWM control (overmodulation PWM control) is suppressed by such processing.

JP 2010-166707 A

  In such an inverter control device, depending on the driving state of the AC motor when switching from rectangular wave voltage control to PWM control (overmodulation PWM control), the torque fluctuation of the AC motor may tend to increase after the switching.

  The main purpose of the inverter control device and the vehicle of the present invention is to suppress the torque fluctuation of the motor after switching from the rectangular wave control to the overmodulation control.

  The inverter control device and the vehicle of the present invention employ the following means in order to achieve the main object described above.

The inverter control device of the present invention is
An inverter control device that controls an inverter for driving a motor by any one of sine wave control, overmodulation control, and rectangular wave control,
When controlling the inverter by sine wave control or overmodulation control, the difference between the d-axis and q-axis currents and the d-axis and q-axis current commands based on the required torque required for the motor and the control gain are used. D-axis and q-axis voltage commands are set by the current feedback control, and the inverter is controlled using the set d-axis and q-axis voltage commands,
Furthermore, when the rectangular wave overmodulation switching is switched from the rectangular wave control to the overmodulation control, the torque fluctuation of the motor due to the rectangular wave overmodulation switching is likely to be large compared to when the fluctuation is not assumed. Use large control gain for current feedback control,
This is the gist.

  In this inverter control device, when the inverter is controlled by sine wave control or overmodulation control, the difference and control between the d-axis and q-axis currents and the d-axis and q-axis current commands based on the required torque required for the motor are controlled. The d-axis and q-axis voltage commands are set by current feedback control using the gain, and the inverter is controlled using the set d-axis and q-axis voltage commands. When the rectangular wave overmodulation switching is switched from the rectangular wave control to the overmodulation control, the motor torque fluctuation due to the rectangular wave overmodulation switching is likely to increase. Gain is used for current feedback control. As a result, when the fluctuation is assumed at the time of switching the rectangular wave overmodulation, the d-axis and q-axis currents can be quickly brought closer to the d-axis and q-axis current commands after the rectangular wave overmodulation switching. As a result, fluctuations (pulsations) in the d-axis and q-axis currents and voltage commands after switching the rectangular wave overmodulation can be suppressed, and the torque required for the motor can be suppressed and the time required for convergence of the torque fluctuations can be reduced. Can be planned. Here, “sine wave control” is control for supplying a pseudo three-phase AC voltage to the motor by pulse width modulation, and “rectangular wave control” is control for supplying a rectangular wave voltage to the motor. “Modulation control” is control for supplying an overmodulation voltage intermediate between a pseudo three-phase AC voltage and a rectangular wave voltage to the motor.

  In such an inverter control device of the present invention, at the time of switching the rectangular wave overmodulation, a shorter integration interval may be used for the current feedback control when the fluctuation is assumed than when the fluctuation is not assumed. .

  In the inverter control device of the present invention, when the inverter is controlled by sine wave control or overmodulation control, current feedback using the difference between the q-axis current and the q-axis current command and the first control gain. A d-axis voltage command is set by control, a q-axis voltage command is set by current feedback control using a difference between the d-axis current and the d-axis current command and the second control gain, and When the variation state is assumed at the time of switching the rectangular wave overmodulation, a value larger than the first control gain may be used as the second control gain. This is because the q-axis current is more likely to fluctuate than the d-axis current immediately after the rectangular wave overmodulation switching when the rectangular wave overmodulation switching is in progress, and then the difference between the d-axis current and the d-axis current command. This is based on the reason that tends to be larger than the difference between the q-axis current and the q-axis current command. By such control, the d-axis and q-axis currents can be brought close to the d-axis and q-axis current commands in a well-balanced manner.

  Furthermore, in the inverter control apparatus of the present invention, the fluctuation assumed state may be a state where the rotation speed of the motor is equal to or less than a predetermined rotation speed and the magnitude of the required torque is equal to or greater than a predetermined value.

  In addition, in the inverter control apparatus of the present invention, when the inverter is controlled by sine wave control or overmodulation control, the required torque is displayed on a current command line indicating a relationship between the required torque and the d-axis and q-axis current commands. Is applied to set the d-axis and q-axis current commands, and the d-axis and q-axis currents of the d-axis current from the current command line are controlled while the inverter is controlled by rectangular wave control. It is also possible to switch from rectangular wave control to overmodulation control when a switching line with a smaller size is reached.

  The vehicle of the present invention includes a traveling motor, an inverter for driving the motor, and the inverter control device of the present invention according to any one of the above-described aspects, that is, basically an inverter for driving the motor. Is controlled by one of sine wave control, overmodulation control, and rectangular wave control, and when the inverter is controlled by sine wave control or overmodulation control, the d-axis and q-axis currents and The d-axis and q-axis voltage commands are set by current feedback control using the difference between the d-axis and q-axis current commands based on the required torque required for the motor and the control gain, and the set d-axis, q The inverter is controlled using a shaft voltage command, and when the rectangular wave overmodulation switching is switched from rectangular wave control to overmodulation control, the motor torque is switched by the rectangular wave overmodulation switching. When click fluctuation of large tends variation assumed state is used to the current feedback control of the large control gain than when the non variation assumed state, and summarized in that comprises an inverter control device.

  Since the vehicle according to the present invention includes the inverter control device according to any one of the above-described aspects, the effect provided by the inverter control device according to the present invention, for example, suppression of torque fluctuation of the motor after the switching of the rectangular wave overmodulation, The same effect as the effect of shortening the time required for the convergence of the torque fluctuation can be obtained.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 carrying the inverter control apparatus as one Example of this invention. 2 is a configuration diagram showing an outline of a configuration of an electric drive system including a motor 32. FIG. It is explanatory drawing which shows an example of the map for electric current command setting. It is explanatory drawing which shows an example of voltage command magnitude | size Vr and voltage command angle (theta) vr. It is explanatory drawing which shows an example of a switching line. 6 is an explanatory diagram showing an example of an approximate relationship between a torque command Tm * of a motor 32, a rotation speed Nm, and a control method of an inverter 34. FIG. 4 is a flowchart showing an example of a rectangular wave overmodulation switching processing routine executed by an electronic control unit 50. It is explanatory drawing which shows an example of the mode of the torque Tm of the motor 32, the modulation factor Rm, voltage phase command (theta) *, or voltage command angle (theta) vr when rectangular wave overmodulation switching is performed in the fluctuation | variation assumption state. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example.

  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 an inverter control device as one embodiment of the present invention. FIG. 2 is a configuration diagram showing an outline of the configuration of an electric drive system including a motor 32. FIG. As shown in FIG. 1, the electric vehicle 20 according to the embodiment drives a motor 32 that can input and output power to a drive shaft 22 connected to drive wheels 26 a and 26 b via a differential gear 24, and a motor 32. Inverter 34, a battery 36 configured as, for example, a lithium ion secondary battery, a power line (hereinafter referred to as a drive voltage system power line) 42 to which the inverter 34 is connected, and a power line (hereinafter referred to as a drive voltage system power line) 42 to which the battery 36 is connected. A boost converter that adjusts the voltage VH of the drive voltage system power line 42 and exchanges power between the drive voltage system power line 42 and the battery voltage system power line 44. 40 and an electronic control unit 50 for controlling the entire vehicle.

  The motor 32 is configured as a well-known synchronous generator motor including a rotor embedded with permanent magnets and a stator wound with a three-phase coil. As shown in FIG. 2, the inverter 34 includes transistors T11 to T16 as six switching elements, and six diodes D11 to D16 connected in parallel to the transistors T11 to T16 in the reverse direction. The 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 drive voltage system power line 42, and each of the connection points between the paired transistors. The three-phase coils (U-phase, V-phase, W-phase) of the motor 32 are connected to each other. Therefore, a rotating magnetic field can be formed in the three-phase coil and the motor 32 can be driven to rotate by adjusting the ratio of the on-time of the transistors T11 to T16 while the voltage is applied to the inverter 34. A smoothing capacitor 46 is connected to the positive and negative buses of the drive voltage system power line 42.

  As shown in FIG. 2, the boost converter 40 is configured as a boost converter including two transistors T31 and T32, two diodes D31 and D32 connected in parallel in opposite directions to the transistors T31 and T32, and a reactor L. . The two transistors T31 and T32 are respectively connected to the positive bus of the drive voltage system power line 42, the negative bus of the drive voltage system power line 42 and the battery voltage system power line 44, and the connection point between the transistors T31 and T32. A reactor L is connected to the positive electrode bus of the battery voltage system power line 44. Therefore, by turning on and off the transistors T31 and T32, the power of the battery voltage system power line 44 is boosted and supplied to the drive voltage system power line 42, or the power of the drive voltage system power line 42 is lowered to reduce the battery voltage system. Or can be supplied to the power line 44. A smoothing capacitor 48 is connected to the positive and negative buses of the battery 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 that stores a processing program, a RAM 56 that temporarily stores data, and an input / output port (not shown) in addition to the CPU 52. . The electronic control unit 50 includes a rotational position θm of the rotor of the motor 32 from a rotational position detection sensor 32a that detects the rotational position of the rotor of the motor 32, and phase currents flowing in the U phase and V phase of the three-phase coil of the motor 32. The phase currents Iu and Iv from the current sensors 23U and 23V, the inter-terminal voltage Vb from the voltage sensor 37a attached between the terminals of the battery 36, and the charge from the current sensor 37b attached to the output terminal of the battery 36. Discharge current Ib, battery temperature Tb from temperature sensor 37c attached to battery 36, voltage of capacitor 46 from voltage sensor 46a attached between terminals of capacitor 46 (voltage of drive voltage system power line 42) VH, capacitor The voltage of the capacitor 48 from the voltage sensor 48a attached between the terminals of the 48 (battery voltage system power IN 44 voltage) VL, ignition signal from the ignition switch 60, shift position SP from the shift position sensor 62 for detecting the operating position of the shift lever 61, and accelerator pedal position sensor 64 for detecting the depression amount of the accelerator pedal 63 The accelerator opening Acc, the brake pedal position BP from the brake pedal position sensor 66 that detects the depression amount of the brake pedal 65, the vehicle speed V from the vehicle speed sensor 68, and the like are input via the input port. From the electronic control unit 50, switching control signals to the transistors T11 to T16 of the inverter 34, switching control signals to the transistors T31 and T32 of the boost converter 40, and the like are output via an output port. The electronic control unit 50 calculates the electrical angle θe, rotational angular velocity ωm, and rotational speed Nm of the rotor of the motor 32 based on the rotational position θm of the rotor of the motor 32 detected by the rotational position detection sensor 32a, Based on the charge / discharge current Ib of the battery 36 detected by the sensor 37b, the storage ratio SOC, which is the ratio of the amount of power that can be discharged from the battery 36 at that time to the total capacity, is calculated, or the calculated storage ratio SOC and the battery temperature Based on Tb, input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 36, are calculated.

  In the thus configured electric vehicle 20 of the embodiment, the electronic control unit 50 sets the required torque Tr * to be output to the drive shaft 22 in accordance with the accelerator opening Acc and the vehicle speed V, and limits the input / output of the battery 36. By dividing Win and Wout by the rotational speed Nm of the motor 32, torque limits Tmin and Tmax are set as upper and lower limits of the torque that may be output from the motor 32, and the required torque Tr * is limited by the torque limits Tmin and Tmax. Then, a torque command Tm * as a torque to be output from the motor 32 is set, and the transistors T11 to T16 of the inverter 34 are subjected to switching control so that the motor 32 is driven by the set torque command Tm *. Further, the target voltage VHtag of the drive voltage system power line 42 is set according to the torque command Tm * of the motor 32 and the rotation speed Nm of the motor 32 so that the voltage VH of the drive voltage system power line 42 becomes the target voltage VHtag. The transistors T31 and T32 of the boost converter 40 are switching-controlled. Hereinafter, control of the inverter 34 will be described.

  In the embodiment, the inverter 34 is controlled by the electronic control unit 50 by any one of sine wave control, overmodulation control, and rectangular wave control. Here, the sine wave control is a pulse width modulation (PWM) control in which the ratio of the on-time of the transistors T11 to T16 is adjusted by comparing the voltage command of the motor 32 and the triangular wave (carrier wave) voltage. In this control, a pseudo three-phase AC voltage obtained by converting an amplitude sinusoidal voltage command is supplied to the motor 32. The overmodulation control is control for supplying the motor 32 with an overmodulation voltage obtained by converting a sinusoidal voltage command having an amplitude larger than the amplitude of the triangular wave voltage in the pulse width modulation control. Further, the rectangular wave control is a control for supplying a rectangular wave voltage to the motor 32. In the sine wave control, the modulation rate (voltage utilization rate) Rm, which is the ratio of the amplitude of the sine wave voltage command to the voltage VH of the drive voltage system power line 42, ranges from 0 to the value Rref1 (about 0.61). In overmodulation control, the modulation rate Rm is in the range of the value Rref1 (about 0.61) to the value Rref2 (about 0.78), and in the rectangular wave control, the modulation rate Rm is the value Rref2 (about 0.78). It becomes constant. Hereinafter, sine wave control and overmodulation control will be described first, and then rectangular wave control will be described.

  In sine wave control and overmodulation control, first, d-axis and q-axis current commands Id * and Iq * are set based on the torque command Tm * of the motor 32. Here, the d-axis is the direction of the magnetic flux formed by the permanent magnet embedded in the rotor of the motor 32, and the q-axis is the electrical angle θe advanced by π / 2 in the positive rotation direction of the motor 32 with respect to the d-axis. It is an angled direction. In the embodiment, the d-axis and q-axis current commands Id * and Iq * are determined in advance by determining the relationship between the torque command Tm * of the motor 32 and the d-axis and q-axis current commands Id * and Iq *. It is stored in the ROM 54 as a command setting map, and when the torque command Tm * of the motor 32 is given, the corresponding d-axis and q-axis current commands Id * and Iq * are derived and set from the stored map. did. Here, the relationship between the torque command Tm * of the motor 32 and the d-axis and q-axis current commands Id * and Iq * is a current for outputting the torque corresponding to the torque command Tm * from the motor 32 in the embodiment. The relationship between the torque command Tm * and the current commands Id * and Iq * that minimize the command magnitude Ir (the square root of the sum of the square of the current command Id * and the square of the current command Iq *) (hereinafter this relationship is shown) The line was called a current command line). An example of the current command setting map is shown in FIG. In the example of FIG. 3, when the torque command Tm * of the motor 32 is the torque T3, the d-axis and q-axis current commands Id * and Iq * corresponding to the torque command Tm * are set. In addition to the current command line, torque command Tm *, and current commands Id * and Iq *, FIG. 3 shows the current command magnitude Ir and the current command angle θir (the q-axis in the direction of the current command magnitude Ir). The angle with respect to the direction) is also illustrated.

  Subsequently, the sum of the phase currents Iu, Iv, and Iw flowing in the U phase, V phase, and W phase of the three-phase coil of the motor 32 is set to 0, and the phase current is expressed by the following equation (1) using the electrical angle θe of the motor 32 Iu and Iv are coordinate-converted (three-phase to two-phase conversion) into d-axis and q-axis currents Id and Iq. Then, using the rotational angular velocity ωm of the motor 32, the d-axis and q-axis currents Id and Iq, and the current commands Id * and Iq *, the d-axis and q-axis voltage commands Vd according to the following equations (2) and (3): Set * and Vq *. Here, the expressions (2) and (3) are relational expressions in current feedback control for canceling the difference between the d-axis and q-axis currents Id and Iq and the current commands Id * and Iq *. The first term on the right side is a feedforward term, the second term on the right side is a proportional term in the feedback term, and the third term on the right side is an integral term in the feedback term. In Expressions (2) and (3), “Ld” and “Lq” are inductances of the d-axis and q-axis, respectively, and “φ” is an induced voltage coefficient. “Kp1” and “Kp2” are proportional term gains, and “Ki1” and “Ki2” are integral term gains. The proportional terms gains Kp1 and Kp2, the integral terms gains Kp2 and Ki2, and the integral terms integration intervals Ti1 and Ti2 are respectively normal values Kp1n, Kp2n, which are determined in consideration of the controllability of the motor 32, and the like. Ki1n, Ki1n, Ti1n, Ti2n were used. Here, with respect to the values Ti1n and Ti2n used as the integration intervals Ti1 and Ti2, in order to maintain the controllability of the motor 32 regardless of the rotational speed Nm of the motor 32, a predetermined period (for example, two periods or 2.. A value corresponding to 5 minutes, 3 periods, etc.) was used.

  Then, using the electrical angle θe, the d-axis and q-axis voltage commands Vd * and Vq * are applied to the U-phase, V-phase, and W-phase of the three-phase coil of the motor 32 by the following equations (4) and (5). Coordinate conversion (two-phase to three-phase conversion) into power voltage commands Vu *, Vv *, and Vw *, and switching the transistors T11 to T16 of the inverter 34 using the voltage commands Vu *, Vv *, and Vw * that have been subjected to coordinate conversion By switching to a PWM signal and outputting it to the transistors T11 to T16 of the inverter 34, switching control of the transistors T11 to T16 is performed. Here, as the amplitude of the sinusoidal voltage command used for the conversion of the PWM signal, the voltage command magnitude Vr (the square root of the sum of the square of the voltage command Vd * and the square of the voltage flow command Vq *) is used. Therefore, the above-described modulation rate Rm is obtained as a ratio of the voltage command magnitude Vr to the voltage VH of the drive voltage system power line 42. For reference, the voltage command magnitude Vr and the voltage command angle θvr (angle of the voltage command magnitude Vr direction with respect to the q-axis direction) when controlling the inverter 34 by sine wave control or overmodulation control. An example is shown in FIG.

  Next, rectangular wave control will be described. In the rectangular wave control, first, using the electrical angle θe of the motor 32, the phase currents Iu and Iv of the motor 32 are coordinate-converted into the currents Id and Iq of the d-axis and the q-axis (3-phase-2) according to the above equation (1). Phase estimation), and an estimated torque Tmest estimated to be output from the motor 32 is obtained based on the d-axis and q-axis currents Id and Iq obtained by the coordinate conversion. Then, a voltage phase command θ * is set by the following equation (6) using the estimated torque Tmest and torque command Tm * of the motor 32, and a rectangular wave voltage based on the set voltage phase command θ * is applied to the motor 32. By outputting a rectangular wave signal to the transistors T11 to T16 of the inverter 34, the transistors T11 to t16 are subjected to switching control. Here, the voltage phase command θ * is a phase command corresponding to the voltage command angle θvr in overmodulation control or sine wave control. Expression (6) is a relational expression in torque feedback control for canceling the difference between the estimated torque Tmest of the motor 32 and the torque command Tm *. In Expression (6), “Kp3” is proportional. Is the gain of the term, and “Ki3” is the gain of the integral term. It should be noted that normal values Kp3n, Ki3n, and Ti3n determined in consideration of controllability of the motor 32 are used for the proportional term gain Kp3, the integral term gain Kp3, and the integral term integration interval Ti3, respectively. . Here, with respect to the value Ti3n used as the integration interval Ti3, in order to maintain the controllability of the motor 32 regardless of the rotational speed Nm of the motor 32, a predetermined cycle (for example, 2 cycles, 2.5 cycles, 3 The value corresponding to the minute) was used.

  By the way, in the embodiment, switching between the sine wave control and the overmodulation control is performed while the modulation rate Rm (= Vr / VH) is the value Rref1 (about 0.61) while the inverter 34 is controlled by the sine wave control. Is switched from sine wave control to over-modulation control when the value exceeds the value, and over-modulation control is switched to sine wave control when the modulation factor Rm becomes equal to or less than the value Rref1 while the inverter 34 is being controlled by over-modulation control. It was supposed to be. Further, in the embodiment, the switching between the overmodulation control and the rectangular wave control is performed while the modulation rate Rm (= Vr / VH) is the value Rref2 (about 0.78) while the inverter 34 is controlled by the overmodulation control. When the inverter reaches 34, the overmodulation control is switched to the rectangular wave control, and while the inverter 34 is controlled by the rectangular wave control, the d-axis and q-axis currents are larger than the current command line. Switching from rectangular wave control to overmodulation control when the switching line becomes smaller is assumed. An example of the switching line is shown in FIG. FIG. 5 also shows a current command line used for sine wave control and overmodulation control for reference. When the inverter 34 is controlled by the rectangular wave control, the d-axis current Id is often larger in the −d-axis direction than the current command line due to the field weakening. Therefore, in the embodiment, in order to suppress frequent switching between overmodulation control and rectangular wave control, the switching line is determined so that the magnitude of the d-axis current Id is smaller than the current command line.

  Thus, when the inverter 34 is controlled by any one of sine wave control, overmodulation control, and rectangular wave control, the torque command Tm * and the rotational speed Nm of the motor 32 and the control method of the inverter 34 (sine wave control, overmodulation control). FIG. 6 shows an example of the approximate relationship with the rectangular wave control. As shown in FIG. 6, the inverter 34 is controlled by sine wave control, overmodulation control, and rectangular wave control in order from the side where the torque command Tm * of the motor 32 and the rotational speed Nm are small. As characteristics of the motor 32 and the inverter 34, in the order of rectangular wave control, overmodulation control, and sine wave control, the output response and controllability of the motor 32 are improved, the output is reduced, and the switching loss of the inverter 34 is increased. Therefore, in the region of low rotational speed and low torque, the output response and controllability of the motor 32 can be improved by controlling the inverter 34 by sine wave control. On the other hand, in the high rotation speed and high torque region, by controlling the inverter 34 by the rectangular wave control, a large torque can be output and the switching loss of the inverter 34 can be reduced.

  Next, the operation of the electric vehicle 20 of the embodiment configured as described above, particularly, the operation at the time of switching the rectangular wave overmodulation to switch from the rectangular wave control to the overmodulation control in the control method of the inverter 34 will be described. FIG. 7 is a flowchart illustrating an example of a rectangular wave overmodulation switching processing routine executed by the electronic control unit 50. This routine is executed when the d-axis and q-axis currents Id and Iq reach the switching line while the inverter 34 is being controlled by the rectangular wave control.

  When the rectangular wave overmodulation switching processing routine is executed, the CPU 52 of the electronic control unit 50 first inputs the torque command Tm * and the rotational speed Nm of the motor 32 (step S100), and the input torque command Tm *. And the rotational speed Nm, it is determined whether or not the torque fluctuation state of the motor 32 due to the rectangular wave overmodulation switching is likely to increase (steps S110 and S120). Specifically, this determination is performed by comparing the absolute value of the torque command Tm * of the motor 32 with the threshold value Tref (step S110) and comparing the rotational speed Nm of the motor 32 with the threshold value Nref (step S120). It was supposed to be. Here, the threshold value Tref and the rotation speed Nm are used to determine the region of the assumed fluctuation state, and can be determined in advance by experiments or analysis. For example, 45 N · m, 50 N · m, 55 N · m, or the like can be used as the threshold value Tref, and 2300 rpm, 2500 rpm, 2700 rpm, or the like can be used as the threshold value Nref.

  Here, the reason for determining whether or not the fluctuation is assumed using the torque command Tm * and the rotation speed Nm of the motor 32 will be described. When the inverter 34 is controlled by rectangular wave control in a region where the absolute value of the torque command Tm * of the motor 32 is large and the rotation speed Nm is small, normally, the voltage phase command θ * (voltage command angle θvr in overmodulation control or sine wave control). A phase command equivalent to 90 degrees (for example, a range of 75 degrees or 80 degrees to 100 degrees or 105 degrees), that is, the d-axis component of the voltage is large and the q-axis component is large. It becomes small. When switching from rectangular wave control to overmodulation control when the d-axis and q-axis currents Id and Iq reach the switching line, the modulation factor Rm (value Rref2) and overmodulation in the rectangular wave control are switched after the switching. Modulation rate Rm fluctuates due to a deviation from modulation rate Rm (= Vr / VH) in control, and d-axis and q-axis currents Id and Iq (on the switching line) and d-axis and q-axis current commands Id at the time of switching. *, Iq * (on the current command line) and the d-axis current Id (q-axis voltage command Vd *) and q-axis current Iq (d-axis voltage command Vd *) fluctuate (pulsate). In particular, when switching from rectangular wave control to overmodulation control when the voltage phase command θ * is close to 90 degrees, the magnitude of the d-axis component of the voltage is large and the magnitude of the q-axis component is large. Because of its small size, the motor 32 is turned on after switching. (Voltage command Vd of the d-axis *) current Iq of the q-axis leading to click varies greatly tends to fluctuate. Therefore, when switching from the rectangular wave control to the overmodulation control in a state where the inverter 34 is controlled by the rectangular wave control in a region where the absolute value of the torque command Tm * of the motor 32 is large and the rotational speed Nm is small, the d-axis is switched after the switching. The voltage command Vd * is greatly fluctuated and the torque fluctuation of the motor 32 is likely to increase. For the above reasons, in the embodiment, it is determined whether or not the fluctuation is assumed using the torque command Tm * of the motor 32 and the rotation speed Nm.

  When the absolute value of the torque command Tm * of the motor 32 is smaller than the threshold value Tref or when the rotational speed Nm of the motor 32 is larger than the threshold value Nref, it is determined that the fluctuation is not assumed, and feedback control in overmodulation control or sine wave control. Normal values Kp1n, Kp2n, Ki1n, Ki2n, Ti1n, Ti2n are set in the proportional terms, integral term gains Kp1, Kp2, Ki1, Ki2 and integral intervals Ti1, Ti2 of the integral term used in (step S130). Control of the inverter 34 by modulation control is started (step S150), and this routine is finished. When the control of the inverter 34 by overmodulation control is thus started, the above-described equations (2), (3) are used using the set proportional term, integral term gains Kp1, Kp2, Ki1, Ki2, and integral term integral intervals Ti1, Ti2. ) To set the d-axis and q-axis voltage commands Vd * and Vq * to control the inverter 34.

  On the other hand, when the absolute value of the torque command Tm * of the motor 32 is equal to or greater than the threshold value Tref and the rotational speed Nm of the motor 32 is equal to or less than the threshold value Nref, it is determined that the fluctuation is assumed, and feedback control in overmodulation control or sine wave control. Are set to values Kp1a, Kp2a, Ki1a, Ki2a that are larger than the normal values Kp1n, Kp2n, Ki1n, Ki2n, respectively, and normal values are used for the integration intervals Ti1, Ti2. Ti1a and Ti2a smaller than the values Ti1n and Ti2n are set (step S140), control of the inverter 34 by overmodulation control is started (step S150), and this routine is terminated. In this way, by setting the gains Kp1, Kp2, Ki1, Ki2 of the proportional term and the integral term and the integration intervals Ti1, Ti2, the d-axis is switched after the rectangular wave overmodulation switching in the assumed state of fluctuation during the rectangular wave overmodulation switching. , Q-axis currents Id and Iq can be quickly brought closer to d-axis and q-axis current commands Id * and Iq *. As a result, fluctuations (pulsations) in the d-axis voltage command Vd * and the voltage command magnitude Vr can be suppressed, and it is necessary to suppress torque fluctuations of the motor 32 after the rectangular wave overmodulation switching and to converge the torque fluctuations. Time can be shortened. Further, when the fluctuation is assumed at the time of switching the rectangular wave overmodulation, the q-axis component of the current (the d-axis component of the voltage) usually changes relatively immediately after the switching of the rectangular wave overmodulation, and the d-axis current Id and the current command Since the deviation from Id * tends to be larger than the deviation between the q-axis current Iq and the current command Iq *, in the embodiment, the values Kp1a, Kp2a, Ki1a, Ki2a are the values Kp2a, Ki2a (q-axis voltage). The gains Kp2 and Ki2 used for setting the command Vq * (see equation (3)) are the values Kp1a and Ki1a (gains Kp1 and Ki1 used for setting the d-axis voltage command Vd * (see equation (2)), respectively. As for values Ti1a and Ti2a, value Ti2a (integral section Ti2 used for setting q-axis voltage command Vq *) is equal to value Ti1a (d-axis voltage command Vd And it shall lay to be smaller than the integration interval Ti1) used for the setting. Thus, after starting control of the inverter 34 by overmodulation control, the d-axis and q-axis currents Id and Iq can be brought close to the d-axis and q-axis current commands Id * and Iq * in a well-balanced manner.

  FIG. 8 is an explanatory diagram illustrating an example of the state of the torque Tm, the modulation factor Rm, the voltage phase command θ *, or the voltage command angle θvr of the motor 32 when the rectangular wave overmodulation switching is performed in a fluctuation assumed state. In the figure, the solid lines increase the gains Kp1, Kp2, Ki1, Ki2 of the proportional term and the integral term and shorten the integral intervals Ti1, Ti2 of the integral term as compared to when the fluctuation is not assumed and when the fluctuation is not assumed. The state of the embodiment is shown, and the alternate long and short dash lines indicate normal values for the proportional term, integral term gains Kp1, Kp2, Ki1, Ki2 and integral term integral intervals Ti1, Ti2 regardless of whether or not fluctuation is assumed. The state of a comparative example is shown. In the example of FIG. 8, the torque command Tm * of the motor 32 is constant. In the case of the comparative example, as indicated by the one-dot chain line in the figure, after the rectangular wave overmodulation switching is performed, the voltage command angle θvr is the d-axis and q-axis current Id and Iq is the d-axis and q-axis current command. The time until convergence near the movement target angle θvrtag as the voltage command angle θvr when reaching the vicinity of Id *, Iq * becomes longer and the modulation rate Rm fluctuates relatively (pulsation), and the torque fluctuation of the motor 32 Becomes larger. On the other hand, in the case of the embodiment, the gains Kp1, Kp2, Ki1, Ki2 of the proportional term and the integral term are increased and the integral intervals Ti1, Ti2 of the integral term are shortened as compared with the case where the fluctuation is not assumed. As shown by the solid line, the time until the voltage command angle θvr converges in the vicinity of the movement target angle θvrtag is shortened, and the fluctuation (pulsation) of the modulation factor Rm is reduced (the fluctuation of the d-axis voltage command Vd * is small). The torque fluctuation of the motor 32 becomes smaller.

  According to the electric vehicle 20 of the embodiment described above, when the inverter 34 is controlled by overmodulation control, the difference between the q-axis current Iq and the q-axis current command Iq *, the control gain of the proportional term, and the integral term The d-axis voltage command Vd * is set by current feedback control using Kp1, Ki1 and the integration interval Ti1 of the integral term, and the difference between the d-axis current command Id and the d-axis current command Id *, the proportional term, and the integral Q-axis voltage command Vq * is set by current feedback control using the term control gains Kp2, Ki2 and the integral term integration interval Ti2, and the set d-axis and q-axis voltage commands Vd *, Vq * are used. In the case of controlling the inverter 34, if the torque fluctuation of the motor 32 due to the rectangular wave overmodulation switching is likely to increase during the rectangular wave overmodulation switching, Since the proportional term and integral term gains Kp1, Kp2, Ki1, and Ki2 are increased and the integral term Ti1 and Ti2 of the integral term are shortened as compared with the case of not being changed, After the rectangular wave overmodulation switching, the d-axis and q-axis currents Id and Iq can be quickly brought closer to the d-axis and q-axis current commands Id * and Iq *, and the torque fluctuation of the motor 32 after the rectangular wave overmodulation switching. It is possible to reduce the time required to suppress the torque and converge the torque fluctuation.

  Further, according to the electric vehicle 20 of the embodiment, in the assumed fluctuation state at the time of switching the rectangular wave overmodulation, the gain Kp2, Ki2 of the proportional term and the integral term used for setting the q-axis voltage command Vq * is set to the d-axis voltage. The proportional term and integral term gain Kp1 and Ki1 used for setting the command Vd * are made larger, and the integral term Ti2 of the integral term used for setting the q-axis voltage command Vq * is used for setting the d-axis voltage command Vd *. Since the integration term is shorter than the integration interval Ti1, the d-axis and q-axis currents Id and Iq can be brought close to the d-axis and q-axis current commands Id * and Iq * in a well-balanced manner.

  In the electric vehicle 20 according to the embodiment, the voltage commands Vd * and Vq * for the d-axis and the q-axis are set when the fluctuation is assumed when the rectangular wave overmodulation is switched compared to when the fluctuation is not assumed when the rectangular wave overmodulation is switched. The gains Kp1, Kp2, Ki1, Ki2 of the proportional term and integral term used in the above are increased and the integral intervals Ti1, Ti2 of the integral term are shortened. However, the gains Kp1, Kp2, Ki1, Ki2 of the proportional term and integral term are used. Is larger than when the fluctuation is not assumed at the time of switching the rectangular wave overmodulation, but the integration sections Ti1 and Ti2 of the integral term may be the same as when the fluctuation is not assumed at the switching of the rectangular wave overmodulation. .

  In the electric vehicle 20 of the embodiment, when the fluctuation is assumed at the time of switching the rectangular wave overmodulation, the proportional term and integral term gains Kp2 and Ki2 used for setting the q-axis voltage command Vq * are set to the d-axis voltage command Vd *. The integral term integral used for setting the d-axis voltage command Vd * is set to be larger than the proportional and integral term gains Kp1 and Ki1 used for setting and the integral term Ti2 of the integral term used for setting the q-axis voltage command Vq *. Although it is assumed to be shorter than the section Ti1, it is sufficient if at least the gains Kp1, Kp2, Ki1, Ki2 of the proportional term and the integral term are made larger than when the fluctuation is not assumed at the time of switching the rectangular wave overmodulation. The proportional and integral term gains Kp2 and Ki2 used for setting the q-axis voltage command Vq * are larger than the proportional and integral term gains Kp1 and Ki1 used for setting the d-axis voltage command Vd *. However, the integral interval Ti1 of the integral term used for setting the d-axis voltage command Vd * and the integral interval Ti2 of the integral term used for setting the q-axis voltage command Vq * may be the same, or d The proportional term and integral term gains Kp1 and Ki1 used to set the voltage command Vd * of the axis are the same as the proportional term and integral term gains Kp2 and Ki2 used to set the voltage command Vq * of the q axis and the d axis The integration term Ti1 of the integral term used for setting the voltage command Vd * may be the same as the integration interval Ti2 of the integral term used for setting the q-axis voltage command Vq *.

  In the electric vehicle 20 according to the embodiment, when switching from rectangular wave control to overmodulation control, proportional term, integral term gains Kp1, Kp2, Ki1, Ki2 and integral term integral intervals Ti1, Ti2 are set and overmodulation control is performed. The control of the inverter 34 is started. Immediately after switching from rectangular wave control to overmodulation control (when overmodulation control is executed for the first time), the feedback terms (2) and (3) above ( The d-axis and q-axis voltage commands Vd * and Vq * may be set using only the feedforward term (first term on the right side) without using the second term and the third term on the right side.

  In the electric vehicle 20 according to the embodiment, when switching from rectangular wave control to overmodulation control, fluctuation occurs when the absolute value of the torque command Tm * of the motor 32 is equal to or greater than the threshold value Tref and the rotational speed Nm of the motor 32 is equal to or less than the threshold value Nref. The assumed state is determined, but for the reason described above, the voltage phase command θ * when switching from rectangular wave control to overmodulation control is within a predetermined range (for example, 75 degrees, 80 degrees to 100 degrees, 105 degrees). It is good also as what is judged that it is a fluctuation assumption state when it is in the range.

  In the embodiment, the present invention is applied to the electric vehicle 20 including the motor 32 that can input and output power to the drive shaft 22 connected to the drive wheels 26a and 26b. As described above, the present invention may be applied to a hybrid vehicle 120 including the engine 122 and the motor 124 connected to the drive shaft 22 through the planetary gear mechanism 126 and the motor 32 capable of inputting / outputting power to / from the drive shaft 22. 10 and the outer rotor 234 connected to the drive shaft 22 connected to the drive wheels 26a and 26b and the inner rotor 232 connected to the crankshaft of the engine 122, as exemplified in the hybrid vehicle 220 of the modified example of FIG. A part of the power from the engine 122 is transmitted to the drive shaft 22 and the remaining power is converted into electric power. The counter rotor motor 230 may be provided, or the motor 32 is attached to the drive shaft 22 and the engine is connected to the rotation shaft of the motor 32 via the clutch 329 as illustrated in the hybrid vehicle 320 of the modified example of FIG. 122 may be connected, and may be applied to a hybrid vehicle 320 that outputs the power from the engine 122 to the drive shaft 22 via the rotation shaft of the motor 32 and outputs the power from the motor 32 to the drive shaft 22. .

  In the embodiments, the present invention has been described as a hybrid vehicle. However, a vehicle other than a vehicle (for example, a train) or an inverter control device may be used.

  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 battery 36 corresponds to “battery”, the motor 32 corresponds to “motor”, the inverter 34 corresponds to “inverter”, and the electronic control unit 50 corresponds to “inverter control device”.

  Here, the “battery” is not limited to the battery 36 configured as a lithium ion secondary battery, but may be any type of battery such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. It doesn't matter. The “motor” is not limited to the motor 32 configured as a synchronous generator motor, and may be any type of motor such as an induction motor. The “inverter” is not limited to the inverter 34 and may be any one as long as it is for driving a motor. As an “inverter control device”, when the inverter 34 is controlled by overmodulation control, the difference between the q-axis current Iq and the q-axis current command Iq *, the proportional term, the integral term control gains Kp1, Ki1 and the integral The d-axis voltage command Vd * is set by current feedback control using the integral interval Ti1 of the term, the difference between the d-axis current Id and the d-axis current command Id *, the proportional term, and the integral term control gain Kp2 , Ki2, and q-axis voltage command Vq * is set by current feedback control using the integration term Ti2 of the integral term, and inverter 34 is controlled using the set d-axis and q-axis voltage commands Vd * and Vq *. When the rectangular wave overmodulation is switched, the torque fluctuation of the motor 32 due to the rectangular wave overmodulation switching is likely to be large. In comparison, the gains Kp1, Kp2, Ki1, Ki2 of the proportional term and the integral term are increased and the integral sections Ti1, Ti2 of the integral term are not shortened. Is controlled by current feedback control using the difference between the d-axis and q-axis current commands based on the required torque required for the d-axis and the q-axis, and the control gain, and the d-axis and q-axis. When the rectangular wave overmodulation switching is performed to control the inverter using the set d-axis and q-axis voltage commands and further switch from the rectangular wave control to the overmodulation control. When a fluctuation assumption state where the torque fluctuation is likely to be large is used, a larger control gain is used for the current feedback control than in a fluctuation assumption state. If it may be used as any thing.

  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 an inverter control device, a vehicle manufacturing industry, and the like.

  20 electric vehicle, 22 drive shaft, 23U, 23V current sensor, 24 differential gear 24, 26a, 26b drive wheel, 32 motor, 34 inverter, 36 battery, 37a voltage sensor, 37b current sensor, 37c temperature sensor, 40 boost converter, 42 drive voltage system power line, 44 battery voltage system power line, 46, 48 capacitor, 46a, 48a voltage sensor, 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, 120, 220, 320 Hybrid vehicle, 12 2 engine, 124 motor, 126 planetary gear mechanism, 230 rotor motor, 232 inner rotor, 234 outer rotor, 329 clutch, D11 to D16, D31, D32 diode, L reactor, T11 to T16, T31, T32 transistor.

Claims (5)

An inverter control device that controls an inverter for driving a motor by any one of sine wave control, overmodulation control, and rectangular wave control,
When controlling the inverter by sine wave control or overmodulation control, the difference between the d-axis and q-axis currents and the d-axis and q-axis current commands based on the required torque required for the motor and the control gain are used. D-axis and q-axis voltage commands are set by the current feedback control, and the inverter is controlled using the set d-axis and q-axis voltage commands,
Furthermore, when the rectangular wave overmodulation switching is switched from the rectangular wave control to the overmodulation control, the torque fluctuation of the motor due to the rectangular wave overmodulation switching is likely to be large compared to when the fluctuation is not assumed. Use large control gain for current feedback control,
Inverter control device. The inverter control device according to claim 1,
At the time of switching the rectangular wave overmodulation, when the fluctuation is assumed, a shorter integration interval is used for the current feedback control than when the fluctuation is not assumed.
Inverter control device. The inverter control device according to claim 1 or 2,
When controlling the inverter by sine wave control or overmodulation control, the d-axis voltage command is set by current feedback control using the difference between the q-axis current and the q-axis current command and the first control gain. And setting the q-axis voltage command by current feedback control using the difference between the d-axis current and the d-axis current command and the second control gain,
Further, at the time of the fluctuation assumed state at the time of switching the rectangular wave overmodulation, a value larger than the first control gain is used for the second control gain.
Inverter control device. An inverter control device according to any one of claims 1 to 3,
The fluctuation assumed state is a state where the rotation speed of the motor is equal to or lower than a predetermined rotation speed and the magnitude of the required torque is equal to or higher than a predetermined value.
Inverter control device.   A vehicle comprising: a traveling motor; an inverter for driving the motor; and the inverter control device according to any one of claims 1 to 4.

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