JP4380650B2 - Electric drive control device and electric drive control method - Google Patents

Description

  The present invention relates to an electric drive control device and an electric drive control method.

  Conventionally, in an electric vehicle, for example, an electric vehicle, a drive motor is provided as an electric machine, and in a hybrid vehicle, a drive motor and a generator are provided as first and second electric machines. ing. The drive motor and the generator are both rotatably arranged, a rotor having a magnetic pole pair composed of N-pole and S-pole permanent magnets, and arranged radially outward from the rotor, U A stator having phase, V-phase, and W-phase stator coils is provided.

  An electric drive device is disposed to drive the drive motor or the generator and generate a drive motor torque that is the torque of the drive motor or a generator torque that is the torque of the generator. A drive motor control device for driving the drive motor and a generator control device for driving the generator are arranged as an electric machine control device, and are generated in the drive motor control device and the generator control device. By sending U-phase, V-phase and W-phase pulse width modulation signals to the inverter, and supplying phase currents generated in the inverter, ie, U-phase, V-phase and W-phase currents, to the respective stator coils The drive motor torque is generated or the generator torque is generated.

  In the drive motor control device, feedback control is performed by vector control calculation on a dq axis model in which the d axis is taken in the direction of the magnetic pole pair in the rotor and the q axis is taken in a direction perpendicular to the d axis. For this purpose, the drive motor control device detects the current supplied to each stator coil, the magnetic pole position of the rotor, the DC voltage at the inlet of the inverter, etc., and the detected current, that is, the detected current is based on the magnetic pole position. Conversion to d-axis current and q-axis current, and then referring to a current command value map, current command values representing target values of d-axis current and q-axis current, that is, d-axis current command value and q-axis current command And a target value of the d-axis voltage and the q-axis voltage based on a deviation between the d-axis current and the d-axis current command value, a deviation between the q-axis current and the q-axis current command value, and a parameter of the drive motor. The d-axis voltage command value and the q-axis voltage command value representing the above are calculated.

  In the current command value map, a d-axis current command value and a q-axis current command value are recorded in association with the drive motor target torque representing the target value of the drive motor torque, the DC voltage, and the angular velocity. The parameter is composed of a counter electromotive voltage constant MIf, a winding resistance Ra of each stator coil, inductances Ld, Lq, and the like, and an interference term is calculated in order to suppress interference between the d axis and the q axis. It is used for performing (for example, refer patent document 1).

  By the way, for example, in the drive motor, in particular, the drive motor that generates reluctance torque, when voltage saturation occurs, field weakening control is performed, and the d-axis current command value and the q-axis current command value are changed. To secure a control area.

However, as the d-axis current command value and the q-axis current command value change, the inductances Ld and Lq as parameters change, so the characteristics of the current control system also change. Therefore, by expressing the inductances Ld and Lq as a function of the d-axis current and the q-axis current, the characteristics of the current control system can be handled as constant.
JP-A-11-150996

  However, in the conventional drive motor control device, when the operating state of the drive motor fluctuates and an external factor is applied, the detected current may fluctuate, and the d-axis current and the q-axis current fluctuate accordingly. As a result, the inductances Ld and Lq fluctuate, and the drive motor cannot be driven stably.

  The present invention solves the problems of the conventional drive motor control device, and can stably drive the electric machine even when the current command value changes or the operating state of the electric machine changes. An object is to provide an electric drive control device and an electric drive control method.

  Therefore, in the electric drive control device of the present invention, the current command value calculation processing means for calculating the current command value based on the electric machine target torque that represents the target value of the torque of the electric machine, and the DC voltage is divided by the angular velocity. Parameter calculation processing means for calculating the inductance based on the voltage speed ratio and the electric machine target torque, and voltage command value calculation processing means for calculating the voltage command value based on the current command value and the inductance. .

  In the electric drive control method of the present invention, the current command value is calculated based on the electric machine target torque that represents the target value of the electric machine torque, and the voltage speed ratio calculated by dividing the DC voltage by the angular velocity and the electric motor are calculated. An inductance is calculated based on the machine target torque, and a voltage command value is calculated based on the current command value and the inductance.

  According to the present invention, in the electric drive control device, the current command value calculation processing means for calculating the current command value based on the electric machine target torque representing the target value of the torque of the electric machine, and the DC voltage is divided by the angular velocity. Parameter calculation processing means for calculating the inductance based on the voltage speed ratio and the electric machine target torque, and voltage command value calculation processing means for calculating the voltage command value based on the current command value and the inductance. .

  In this case, since the inductance is represented by a two-dimensional function of the operating state variable and the electric machine target torque, the inductance can be set appropriately even if the current command value changes.

  In addition, since the actual current is not used to represent the inductance, the electric machine can be driven stably even when the operating conditions of the electric machine fluctuate and external factors are added.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, an electric drive device that is mounted on an electric vehicle as an electric vehicle, a hybrid type vehicle, or the like and that drives a drive motor as an electric machine, and an electric drive control device for operating the electric drive device will be described. .

1 is a block diagram of a current control unit according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of an electric drive device according to an embodiment of the present invention, and FIG. 3 is a schematic diagram of a drive motor control device according to an embodiment of the present invention. FIG. 4 is a diagram showing a maximum drive motor target torque map in the embodiment of the present invention, FIG. 5 is a diagram showing a first current command value map in the embodiment of the present invention, and FIG. The figure which shows the 2nd electric current command value map in embodiment of this invention, FIG. 7 is the characteristic view of the drive motor in embodiment of this invention, FIG. 8 is the characteristic figure of the static inductance in embodiment of this invention, FIG. 9 is a characteristic diagram of dynamic inductance in the embodiment of the present invention, FIG. 10 is a diagram showing a use range of parameters in the embodiment of the present invention, and FIG. 11 is a diagram in the embodiment of the present invention. That first diagram showing an inductance map, FIG. 12 is a diagram showing a second inductance map according to the embodiment of the present invention. In FIG. 4, the horizontal axis represents the angular velocity ω, the vertical axis represents the maximum drive motor target torque TMmax ^* , and in FIG. 5, the horizontal axis represents the drive motor target representing the target value of the drive motor torque, which is the torque of the drive motor 31. the torque TM ^*, the vertical axis of the d-axis current command value id ^*, 6, the d-axis current command value id ^* on the horizontal axis, the q-axis current command value iq ^* on the vertical axis, in FIG. 7, the horizontal In FIG. 8, the vertical axis represents d (q) -axis current id (iq), the vertical axis represents magnetic flux φd (φq), the horizontal axis represents d (q) -axis current id (iq), and the vertical axis represents static inductance Lds ( Lqs) in FIG. 9, the horizontal axis represents d (q) -axis current id (iq), the vertical axis represents dynamic inductance Ldd (Lqd), and in FIG. 10, the horizontal axis represents d-axis current command value id ^* . the q-axis current command value iq ^* on the vertical axis, in FIG. 11, the horizontal axis The drive motor target torque TM ^*, the static inductance Lds (Lqs) on the vertical axis, in FIG. 12, the horizontal axis drive motor target torque TM ^*, are taking the dynamic inductance Ldd (Lqd) on the vertical axis.

  In the figure, reference numeral 31 denotes a drive motor as an electric machine. The drive motor 31 is attached to, for example, a drive shaft of an electric vehicle and is rotatably arranged, and is radially outside the rotor. And a stator disposed on the side. The rotor includes a rotor core and permanent magnets arranged at equal pitches at a plurality of locations in the circumferential direction of the rotor core, and a magnetic pole pair is configured by the S pole and the N pole of the permanent magnet. In addition, the stator includes a stator core in which teeth are formed by projecting radially inward at a plurality of locations in the circumferential direction, and U-phase, V-phase, and W-phase coils wound around the teeth. Stator coils 11-13.

  A magnetic pole position sensor 21 is disposed on the output shaft of the rotor as a magnetic pole position detector for detecting the magnetic pole position of the rotor. The magnetic pole position sensor 21 generates a magnetic pole position signal SGθ as a sensor output, and the electric machine It is sent to a drive motor control device 45 as a control device. Note that a resolver can be provided as a magnetic pole position detection unit in place of the magnetic pole position sensor 21, and a magnetic pole position signal can be generated by the resolver.

  In order to drive the drive motor 31 and drive the electric vehicle, a direct current from the battery 14 is converted into a phase current, that is, a U-phase, V-phase, and W-phase current Iu by an inverter 40 as a current generator. , Iv, and Iw, and the currents Iu, Iv, and Iw of the respective phases are supplied to the stator coils 11 to 13, respectively.

  For this purpose, the inverter 40 includes transistors Tr1 to Tr6 as six switching elements, sends the drive signals generated in the drive circuit 51 to the transistors Tr1 to Tr6, and selectively selects the transistors Tr1 to Tr6. By turning on and off, the currents Iu, Iv, and Iw of each phase can be generated. As the inverter 40, a power module such as an IGBT formed by incorporating 2 to 6 switching elements into one package, or an IPM formed by incorporating a drive circuit or the like in the IGBT is used. can do.

  A voltage sensor 15 serving as a voltage detection unit is disposed on the inlet side when supplying current from the battery 14 to the inverter 40. The voltage sensor 15 detects the DC voltage Vdc on the inlet side of the inverter 40, and drives the motor. Send to control device 45. In addition, a battery voltage can also be used as the DC voltage Vdc, and in this case, a battery voltage sensor is disposed in the battery 14 as a voltage detection unit.

  The drive motor 31, the inverter 40, the drive circuit 51, drive wheels (not shown), and the like constitute an electric drive device, and the electric drive device and the drive motor control device 45 constitute an electric drive control device. Reference numeral 17 denotes a capacitor.

  By the way, since the stator coils 11 to 13 are star-connected, when the current values of two phases of each phase are determined, the current values of the remaining one phase are also determined. Therefore, in order to control the currents Iu, Iv, Iw of each phase, for example, current detection for detecting the U-phase and V-phase currents Iu, Iv on the lead wires of the U-phase and V-phase stator coils 11, 12. Current sensors 33 and 34 are arranged, and the current sensors 33 and 34 send detected currents to the drive motor controller 45 as detected currents iu and iv.

  In addition to a CPU (not shown) that functions as a computer, the drive motor control device 45 is provided with a recording device (not shown) such as a RAM and a ROM for recording data and various programs. First and second current command value maps are set in the recording device. Note that an MPU can be used instead of the CPU.

  Various programs, data, and the like are recorded in the ROM, but the programs, data, and the like may be recorded on other recording media such as a hard disk provided as an external storage device. it can. In this case, for example, a flash memory is provided in the drive motor control device 45, and the program, data, etc. are read from the recording medium and recorded in the flash memory. Therefore, the program, data, etc. can be updated by exchanging an external recording medium.

  Next, the operation of the drive motor control device 45 will be described.

First, a position detection processing unit (not shown) of the drive motor control device 45 performs a position detection process, reads the magnetic pole position signal SGθ sent from the magnetic pole position sensor 21, and based on the magnetic pole position signal SGθ, reads the magnetic pole position θ. Is detected. The rotational speed calculation processing means of the position detection processing means performs rotational speed calculation processing, and calculates the angular speed ω of the drive motor 31 based on the magnetic pole position signal SGθ. The rotational speed calculation processing means has a drive motor rotational speed NM that is the rotational speed of the drive motor 31 based on the angular speed ω, where p is the number of magnetic poles.
NM = 60 · (2 / p) · ω / 2π
Is also calculated. The electric motor rotation speed is constituted by the drive motor rotation speed NM.

A detection current acquisition processing unit (not shown) of the drive motor control device 45 performs a detection current acquisition process, reads and acquires the detection currents iu and iv, and also detects a detection current iw based on the detection currents iu and iv.
iw = -iu-iv
Is obtained by calculating.

Next, a drive motor control processing unit (not shown) of the drive motor control device 45 performs a drive motor control process to obtain a drive motor target torque TM ^* , detected currents iu, iv, iw, a magnetic pole position θ, a DC voltage Vdc, and the like. Based on this, the drive motor 31 is driven. In the present embodiment, in the drive motor control device 45, a vector on a dq axis model in which the d axis is taken in the direction of the magnetic pole pair in the rotor and the q axis is taken in the direction perpendicular to the d axis. Feedback control by control calculation is performed.

For this purpose, vehicle speed detection processing means (not shown) of the drive motor control device 45 performs vehicle speed detection processing, and detects and detects a vehicle speed V corresponding to the drive motor rotation speed NM based on the drive motor rotation speed NM. The vehicle speed V is sent to a vehicle control device (not shown) that controls the entire electric vehicle. Then, the vehicle command value calculation processing means of the vehicle control device performs the vehicle command value calculation processing, reads the vehicle speed V and the accelerator opening α, and based on the vehicle speed V and the accelerator opening α, the vehicle required torque TO ^* Is calculated, a drive motor target torque TM ^* is generated corresponding to the vehicle required torque TO ^* , and is sent to the torque command value limit processing means of the transmission control device that controls the entire electric drive device.

When the drive motor target torque TM ^* is sent from the vehicle command value calculation processing means, the torque command value restriction processing means performs torque command value restriction processing, and the DC voltage Vdc, angular velocity ω, and drive motor target. The torque TM ^* is read, the maximum drive motor target torque map of FIG. 4 set in the recording device is referred to, the maximum drive motor target torque TMmax ^* corresponding to the DC voltage Vdc and the angular velocity ω is read, and the drive motor target torque is read. TM ^* is limited so as not to exceed the maximum drive motor target torque TMmax ^*, and the drive motor target torque TM ^* is sent to the drive motor controller 45.

In the maximum drive motor target torque map, when the angular velocity ω is equal to or less than a predetermined value ω1, the maximum drive motor target torque TMmax ^* takes a constant value, and when the angular velocity ω exceeds the value ω1, the maximum drive motor target torque TMmax. ^* Is reduced to a curved line. In the region where the angular velocity ω exceeds the value ω1, the maximum drive motor target torque TMmax ^* is set larger as the DC voltage Vdc is higher and smaller as the DC voltage Vdc is lower. The maximum electric motor target torque map is constituted by the maximum driving motor target torque map, and the maximum electric machine target torque is constituted by the maximum driving motor target torque TMmax ^* .

In the drive motor control device 45, the drive motor control processing means drives the drive motor 31 based on the drive motor target torque TM ^* , so that a current command value setting unit 46 as current command value setting processing means. , Field weakening control unit 47 as field weakening control processing means, voltage command value setting unit 48 as voltage command value setting processing means, three-phase two-phase conversion unit 49 as first phase conversion processing means, and output signal generation processing means The PWM generator 50 is provided.

The current command value setting unit 46 includes a d-axis current command value calculation unit (maximum torque control unit) 53 and a subtractor 55 as first axis current command value setting processing means for performing a current command value setting process. The q-axis current command value calculation unit (equal torque control unit) 54 is provided as the second axis current command value setting processing means, and the d-axis current command value calculation unit 53 and the subtractor 55 are provided with the first axis current command value A setting process is performed to calculate a d-axis current command value id ^* as a first current command value representing a target value of the d-axis current id, and the q-axis current command value calculation unit 54 A value setting process is performed to calculate a q-axis current command value iq ^* as a second current command value representing the target value of the q-axis current iq. The d-axis current command value calculation unit 53 uses the first current command value calculation processing unit and the maximum torque control processing unit, and the q-axis current command value calculation unit 54 uses the second current command value calculation processing unit and the equal torque. The controller processing means is constituted by the subtractor 55 to constitute current command value adjustment processing means.

  Further, the field weakening control unit 47 performs a field weakening control process, and includes a subtractor 58 as a voltage saturation index calculation processing means and a d as a field saturation current calculation processing means as a voltage saturation determination processing means. An axis current adjustment control unit 59 is provided to perform field weakening control processing. When the DC voltage Vdc (or battery voltage) decreases or the angular velocity ω (or drive motor rotational speed NM) increases, the field weakening as an adjustment value is obtained. A magnetic current Δid is generated, and field weakening control is automatically performed. The d-axis current adjustment control unit 59 is configured by an integrator.

  The three-phase to two-phase conversion unit 49 performs three-phase to two-phase conversion in the first phase conversion process, reads the magnetic pole position θ, and uses the detected currents iu, iv, and iw as the d-axis current id and the q-axis current. iq, d-axis current id and q-axis current iq are calculated as actual currents and sent to voltage command value setting unit 48.

  The voltage command value setting unit 48 serves as a current control processing unit and a current control unit 61 as a shaft voltage command value setting processing unit and a voltage control processing unit in order to perform a voltage command value setting process. And the voltage control part 62 as a 2nd phase conversion process means is provided.

  The PWM generator 50 performs output signal generation processing, generates pulse width modulation signals Mu, Mv, and Mw as output signals and sends them to the drive circuit 51.

  The drive circuit 51 receives the pulse width modulation signals Mu, Mv, Mw of each phase, generates six drive signals, and sends the drive signals to the inverter 40. The inverter 40 switches the transistors Tr1 to Tr6 to generate currents Iu, Iv, Iw of the respective phases based on the pulse width modulation signals Mu, Mv, Mw, and the currents Iu, Iv, Iw of the respective phases. Is supplied to the stator coils 11 to 13 of the drive motor 31.

In this manner, torque control is performed based on the drive motor target torque TM ^* , and the drive motor 31 is driven to run the electric vehicle.

  Next, the operation of the current command value setting unit 46 will be described.

In this case, the current command value setting unit 46 reads the drive motor target torque TM ^* , the angular velocity ω, and the DC voltage Vdc, and calculates the d-axis current command value id ^* and the q-axis current command value iq ^* .

For this purpose, the d-axis current command value calculation unit 53 performs a first current command value calculation process and a maximum torque control process, reads the drive motor target torque TM ^*, and is set in the recording apparatus in FIG. Referring to the current command value map 1, the d-axis current command value id ^* corresponding to the drive motor target torque TM ^* is calculated by reading, and the d-axis current command value id ^* is sent to the subtractor 55.

In this case, in the first current command value map, the d-axis current command value id ^* is set so that the absolute value of the current amplitude command value is minimized in order to achieve the drive motor target torque TM ^* . In the first current command value map, the drive motor target torque TM ^* takes a positive or negative value, whereas the d-axis current command value id ^* takes a negative value, and the drive motor target torque TM If ^* is zero (0), d-axis current command value id ^* is zero, the d-axis current command value id ^* is the negative direction as the driving motor target torque TM ^* is increased in the positive or negative direction Set to be larger.

When the d-axis current command value id ^* is calculated in this way, the q-axis current command value calculation unit 54 performs the second current command value calculation process and the equal torque control unit process, and the drive motor target torque TM ^* and field weakening current Δid are read, and the second current command value map of FIG. 6 is referred to, and q-axis current command value iq ^* corresponding to drive motor target torque TM ^* and d-axis current command value id ^* is obtained. The q-axis current command value iq ^* is calculated by reading and sent to the current control unit 61.

In the second current command value map, the d-axis current command value id ^* increases in the negative direction and the q-axis current command value iq ^* increases in the positive or negative direction as the drive motor target torque TM ^* increases. The d-axis current command value id ^* decreases in the negative direction as the drive motor target torque TM ^* decreases, and the q-axis current command value iq ^* decreases in the positive or negative direction. When the drive motor target torque TM ^* is constant, when the d-axis current command value id ^* increases in the negative direction, the q-axis current command value iq ^* decreases in the positive or negative direction.

  Next, the operation of the field weakening control unit 47 will be described.

  By the way, in the drive motor 31, a counter electromotive force is generated as the rotor rotates. However, as the drive motor rotational speed NM increases, the terminal voltage of the drive motor 31 increases, and the terminal voltage becomes a threshold value. If the threshold value is exceeded, voltage saturation occurs and output by the drive motor 31 becomes impossible.

Therefore, a modulation factor calculation processing means (not shown) of the voltage control unit 62 performs a modulation factor calculation process, reads the d-axis voltage command value vd ^* , the q-axis voltage command value vq ^*, and the DC voltage Vdc, and calculates the voltage amplitude | v |

Is the theoretical maximum voltage Vmax.
Vmax = 0.78 × Vdc
By dividing by the modulation factor m

Is sent to the subtractor 58. The modulation factor m is a value representing the degree of voltage saturation.

The subtractor 58 performs a voltage saturation index calculation process, reads the modulation factor m, and also calculates a command value of the modulation factor m calculated in advance by a modulation factor command value calculation unit (not shown), that is, a modulation factor command value. voltage saturation index Δm, which is an index indicating the degree of voltage saturation by reading k
Δm = m−k
And the voltage saturation index Δm is sent to the d-axis current adjustment control unit 59.

  Subsequently, the d-axis current adjustment control unit 59 performs voltage saturation determination processing and field weakening current calculation processing, integrates the voltage saturation index Δm at each control timing, calculates an integrated value ΣΔm, and calculates the integrated value. It is determined whether voltage saturation has occurred depending on whether ΣΔm takes a positive value. If the integrated value ΣΔm takes a positive value and voltage saturation has occurred, it is weakened by multiplying the integrated value ΣΔm by a proportional constant. The field weakening current Δid for performing field control is calculated and set, and when the integrated value ΣΔm takes a value of zero or less and no voltage saturation occurs, the field weakening current Δid is made zero.

The field weakening current Δid is sent to the q-axis current command value calculation unit 54 and the subtractor 55. The subtractor 55 performs a current command value adjustment process, and receives the field weakening current Δid. adjust the d-axis current command value id ^* by subtracting the field weakening current Δid from the current command value id ^*, and sends the adjusted d-axis current command value id ^* to the current controller 61.

In this case, when the field weakening current Δid takes a zero value, the d-axis current command value id ^* is not substantially adjusted, and field weakening control is not performed. On the other hand, when the field weakening current Δid takes a positive value, the d-axis current command value id ^* is adjusted to increase the value in the negative direction, and field weakening control is performed.

Therefore, as shown in FIG. 6, when the value of the d-axis current command value id ^* sent to the subtractor 55 is ida ^* , the field weakening current Δid is zero and field weakening control is not performed. If, in the q-axis current command value calculating section 54, the q-axis current command value iq ^* values iqa corresponding to the value ida ^{* *} is read. On the other hand, when the field weakening current Δid takes a positive value and field weakening control is performed, for example, in the subtractor 55 and the q-axis current command value calculation unit 54, the d-axis current command value id ^* is negative. In this direction, the value idb ^* is increased by the field weakening current Δid. Therefore, q-axis current command value iq ^* is set to be smaller in value iqa ^* more positive direction in the q-axis current command value calculating section 54, a value Iqb ^*.

  Next, the operation of the voltage command value setting unit 48 will be described.

The current control unit 61 performs current control processing and shaft voltage command value setting processing, and the d-axis current command value id ^* and q-axis current command sent from the d-axis current command value calculation unit 53 via the subtractor 55. The q-axis current command value iq ^* sent from the value calculation unit 54 is received, the d-axis current id and the q-axis current iq are received from the three-phase two-phase conversion unit 49, and the drive motor target torque TM ^* and the voltage speed ratio are also received. Feedback control is performed by reading Vdc / ω. An operation state variable calculation processing unit (not shown) of the drive motor control device 45 performs an operation state variable calculation process and divides the DC voltage Vdc by the angular velocity ω, thereby representing an operation state variable of the drive motor 31. As described above, the voltage speed ratio Vdc / ω is calculated.

In the feedback control, the current control unit 61 uses the d-axis voltage command value as the first and second axis voltage command values based on the d-axis current command value id ^* and the q-axis current command value iq ^*. The value vd ^* and the q-axis voltage command value vq ^* are calculated and set.

Therefore, the current control unit 61 calculates a current deviation δid between the d-axis current command value id ^* and the d-axis current id, and a current deviation δiq between the q-axis current command value iq ^* and the q-axis current iq, Based on the current deviations δid and Δiq and the parameters of the drive motor 31, proportional integral term calculation including proportional control and integral control is performed.

The voltage control unit 62 performs voltage control processing and phase voltage command value setting processing, reads the d-axis voltage command value vd ^* , the q-axis voltage command value vq ^* , the DC voltage Vdc, and the magnetic pole position θ, Voltage command values vu ^* , vv ^* , and vw ^* as first to third phase voltage command values are calculated by three-phase conversion and sent to the PWM generator 50.

The d-axis voltage command value vd ^* , the q-axis voltage command value vq ^*, and the voltage command values vu ^* , vv ^* , vw ^* constitute a voltage command value.

  The parameter includes a back electromotive force constant MIf, a winding resistance Ra of each stator coil, inductances Ld and Lq, and the like, and an interference term is calculated in order to suppress interference between the d axis and the q axis. Used for.

  By the way, the inductances Ld and Lq change depending on the operation state when driving the drive motor 31, but if the characteristics of the control system change accordingly, the drive motor 31 cannot be driven stably.

In addition, for example, in the drive motor 31, in particular, in the drive motor that generates reluctance torque, the d-axis current command value id ^* and the q-axis current are accompanied by the field weakening control as described above. The inductances Ld and Lq also change when the command value iq ^* changes.

Therefore, when the inductances Ld and Lq are used as fixed values, the characteristics of the current control unit 61 change due to the inductance that changes depending on the d-axis current command value id ^* and the q-axis current command value iq ^* .

Therefore, in the present embodiment, as the inductances Ld and Lq, static inductances Lds and Lqs as first inductances are used, dynamic inductances Ldd and Lqd as second inductances are used, and the drive motor 31 is used. The static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd are changed and used in accordance with the driving state at the time of driving and the drive motor target torque TM ^* .

Further, the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd are expressed as a two-dimensional function of the voltage / speed ratio Vdc / ω and the drive motor target torque TM ^* .

  Next, the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd will be described.

  By the way, when the voltage speed ratio Vdc / ω is kept constant and the d-axis current id (q-axis current iq) is increased from zero, the magnetic flux φd (φq) generated by the coil is measured. As shown, the magnetic flux φd (φq) increases as the d-axis current id (q-axis current iq) increases. Therefore, in a region where the d-axis current id (q-axis current iq) is small, the magnetic flux φd (φq) can be greatly changed by only a slight change in the d-axis current id (q-axis current iq). On the other hand, in the region where the d-axis current id (q-axis current iq) is large, the magnetic flux φd (φq) can hardly be changed even if the d-axis current id (q-axis current iq) is changed.

Therefore, when static flux Lds, Lqs is obtained by dividing magnetic flux φd (φq) by d-axis current id (q-axis current iq),
Lds = φd / id
Lqs = φq / iq
Thus, the relationship between the d-axis current id (q-axis current iq) and the static inductances Lds and Lqs as shown in FIG. 8 can be obtained. In this case, the static inductances Lds and Lqs when the d-axis current id (q-axis current iq) is increased from zero are gradually decreased.

  Also, when the magnetic flux φd (φq) is differentiated by the d-axis current id (q-axis current iq), the dynamic inductances Ldd and Lqd are obtained.

Thus, the relationship between the d-axis current id (q-axis current iq) and the dynamic inductances Ldd and Lqd as shown in FIG. 9 can be obtained. In this case, the dynamic inductances Ldd and Lqd are large in the region where the d-axis current id (q-axis current iq) is small, and the dynamic inductances Ldd and Lqd are large in the region where the d-axis current id (q-axis current iq) is large. In a region where the d-axis current id (q-axis current iq) is small, the d-axis voltage command value vd ^* (q-axis voltage command value vq ^* ) with respect to the change amount of the d-axis current id (q-axis current iq). In the region where the d-axis current id (q-axis current iq) is large, the d-axis voltage command value vd ^* (q-axis voltage command value vq) with respect to the change amount of the d-axis current id (q-axis current iq). ^* ) The amount of change can be reduced.

  The static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd have different amounts of change when the d-axis current id (q-axis current iq) changes. In calculating the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd, a calculated value or an estimated value is used as the magnetic flux φd (φq).

Incidentally, in the present embodiment, the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd are expressed as a two-dimensional function of the voltage / speed ratio Vdc / ω and the drive motor target torque TM ^* as described above. It is recorded in the recording device as an inductance map.

Therefore, appropriate static inductances Lds and Lqs and dynamic inductances Ldd and Lqd can be used according to the voltage speed ratio Vdc / ω and the drive motor target torque TM ^* .

That is, in FIG. 10, Li (i = 1, 2,...) Is represented by an elliptical shape, and is an output limiting curve when the voltage speed ratio Vdc / ω is constant, and the voltage speed ratio Vdc. The ellipse becomes larger as / ω becomes larger, and the ellipse becomes smaller as the voltage speed ratio Vdc / ω becomes smaller. Lm is a maximum torque command curve that can maximize the drive motor target torque TM ^* . When the equal torque command curve shown in FIG. 6 is superimposed on FIG. 10, the equal torque command curve and the maximum torque command curve Lm intersect, and the intersection becomes an operation point of the drive motor 31. Can be acquired as the d-axis current command value id ^* and the q-axis current command value iq ^* .

When the drive motor target torque TM ^* increases, the d-axis current command value id ^* and the q-axis current command value iq ^* change along the maximum torque command curve Lm as indicated by the arrows, and the drive motor 31 When the terminal voltage exceeds the threshold value, field weakening control is performed, and as indicated by the arrow, it changes along the output limit curve Li determined by the voltage speed ratio Vdc / ω at that time.

Thus, when the voltage / speed ratio Vdc / ω and the drive motor target torque TM ^* change, as described above, the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd have the voltage / speed ratio Vdc / ω and the drive. Since the motor target torque TM ^* is expressed by a two-dimensional function, the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd are changed even if the d-axis current command value id ^* and the q-axis current command value iq ^* change. It can be set appropriately.

In addition, the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd are not functions of the d-axis current id and the q-axis current iq which are actual currents, but two-dimensional of the voltage speed ratio Vdc / ω and the drive motor target torque TM ^* . It is expressed by function. In this case, even if the d-axis current id and the q-axis current iq fluctuate when the operating condition of the drive motor 31 fluctuates and an external factor is added to the voltage / velocity ratio Vdc / ω, the voltage / velocity ratio Vdc / The change in inductance due to the fluctuation amount of ω is less than that due to the change in d-axis current id and q-axis current iq. Further, the drive motor target torque TM ^* is sent from the vehicle control device, and basically does not vary even if the operation condition of the drive motor 31 varies.

  Accordingly, since the static inductances Lds and Lqs and the dynamic inductances Ldd and Lqd can be stabilized, the drive motor 31 can be driven stably.

  Next, details of the current control unit 61 will be described.

  As shown in FIG. 1, the current control unit 61 includes voltage command value calculation units 78 and 79 as first and second voltage command value calculation processing means.

The voltage command value calculation unit 78 includes a subtractor 81 as a first deviation calculation processing unit, a PI term calculation unit 82 as a first proportional integral term calculation processing unit, and an interference as a first interference term calculation processing unit. A term calculation unit 83, an inductance calculation unit (Ld (Vdc / ω, TM ^* )) 84 as a first parameter calculation processing unit, and an adder 85 as a first voltage command value adjustment processing unit. Based on the current deviation δid representing the deviation between the current id and the d-axis current command value id ^* , feedback control is performed so that the d-axis current id becomes the d-axis current command value id ^* .

The voltage command value calculation unit 79 includes a subtracter 86 as a second deviation calculation processing unit, a PI term calculation unit 87 as a second proportional integral term calculation processing unit, and a second interference term calculation processing unit. An interference term calculation unit 88, an inductance calculation unit (Lq (Vdc / ω, TM ^* )) 89 as a second parameter calculation processing unit, and an adder 90 as a second voltage command value adjustment processing unit, Based on the current deviation δiq representing the deviation between the axis current iq and the q-axis current command value iq ^* , feedback control is performed so that the q-axis current iq becomes the q-axis current command value iq ^* .

Therefore, in the voltage command value calculation unit 78, the subtractor 81 performs a first deviation calculation process, reads the d-axis current id and the d-axis current command value id ^* , calculates the current deviation δid, and PI This is sent to the term calculation unit 82.

By the way, when performing feedback control in the voltage command value calculation unit 78, it is preferable to increase the change amount of the d-axis voltage command value vd ^* with respect to the change amount of the d-axis current id in a region where the d-axis current id is small. In a region where the d-axis current id is large, it is preferable to reduce the change amount of the d-axis voltage command value vd ^* with respect to the change amount of the d-axis current id.

For this purpose, the inductance calculator 84 performs a first parameter calculation process, reads the voltage speed ratio Vdc / ω and the drive motor target torque TM ^* , and refers to the first and second inductance maps of FIGS. The static inductance Lds on the d-axis and the dynamic inductance Ldd on the d-axis are calculated, and the static inductance Lds is sent to the interference term calculation unit 83 and the dynamic inductance Ldd is sent to the PI term calculation unit 82.

  Then, the PI term calculation unit 82 performs a first proportional integral term calculation process, reads the current deviation δid and the dynamic inductance Ldd, calculates the voltage drop Vzd based on the current deviation δid and the dynamic inductance Ldd, and adds the adder 85 Send to. Therefore, the PI term calculation unit 82 includes a proportional term calculation unit as a proportional term calculation processing unit, an integral term calculation unit as an integral term calculation processing unit, and an adder for voltage drop calculation as a voltage drop calculation processing unit. Is provided.

The proportional term calculation unit performs a proportional term calculation process, calculates a proportional term calculation gain Gpd (Ldd) represented by a function of the dynamic inductance Ldd according to the dynamic inductance Ldd, a current deviation δid, and a gain Gpd. Voltage drop Vzdp representing the voltage command value of the proportional term based on (Ldd)
Vzdp = Gpd (Ldd) · Δid
Is calculated as a proportional term operation value. The integral term calculation unit performs integral term calculation processing, and a voltage drop Vzdi representing a voltage command value of the integral term based on the current deviation δid and the gain Gid for integral term calculation.
Vzdi = Gid · ΣΔid
Is calculated as an integral term operation value. Further, the voltage drop calculation adder performs a voltage drop calculation process, adds the voltage drops Vzdp and Vzdi, and then adds the voltage drop Vzd.
Vzd = Vzdp + Vzdi
= Gpd (Ldd) · Δid + Gid · ΣΔid
Is calculated.

The interference term calculation unit 83 performs a first interference term calculation process, reads the angular velocity ω, the counter electromotive voltage constant MIf, the d-axis current command value id ^*, and the static inductance Lds, and calculates the angular velocity ω, the counter electromotive voltage constant MIf. , Induced voltage eq induced by d-axis current id of the interference term based on d-axis current command value id ^* and static inductance Lds
eq = −ω (Mif + Lds · id ^* )
Is sent to the adder 90.

On the other hand, in the voltage command value calculation unit 79, the subtractor 86 performs the second deviation calculation process, reads the q-axis current iq and the q-axis current command value iq ^* , calculates the current deviation δiq, and the PI term calculation unit Send to 87.

By the way, when performing feedback control in the voltage command value calculation unit 79, it is preferable to increase the change amount of the q-axis voltage command value vq ^* with respect to the change amount of the q-axis current iq in a region where the q-axis current iq is small. In a region where the q-axis current iq is large, it is preferable to reduce the change amount of the q-axis voltage command value vq ^* with respect to the change amount of the q-axis current iq.

For this purpose, the inductance calculation unit 89 performs a second parameter calculation process, reads the voltage speed ratio Vdc / ω and the drive motor target torque TM ^* , and refers to the first and second inductance maps of FIGS. The static inductance Lqs on the q-axis and the dynamic inductance Lqd on the q-axis are calculated, and the static inductance Lqs is sent to the interference term calculation unit 88 and the dynamic inductance Lqd is sent to the PI term calculation unit 87.

  The DC voltage Vdc and angular velocity ω for calculating the voltage / speed ratio Vdc / ω are filtered by a time constant larger than that of the control system. Therefore, it is possible to suppress the occurrence of vibration in the control system.

  Then, the PI term calculation unit 87 performs the second proportional integral term calculation process, reads the current deviation δiq and the dynamic inductance Lqd, calculates the voltage drop Vzq based on the current deviation δiq and the dynamic inductance Lqd, and adds the adder 90 Send to. Therefore, the PI term calculation unit 87 includes a proportional term calculation unit as a proportional term calculation processing unit, an integral term calculation unit as an integral term calculation processing unit, and an adder for voltage drop calculation as a voltage drop calculation processing unit. Is provided.

Then, the proportional term calculation unit performs proportional term calculation processing, calculates a proportional term calculation gain Gpq (Lqd) represented by a function of the dynamic inductance Lqd according to the dynamic inductance Lqd, and obtains the current deviation δiq and the gain Gpd. Voltage drop Vzqp representing the voltage command value of the proportional term based on (Lqd)
Vzqp = Gpq (Lqd) · Δiq
Is calculated as a proportional term operation value. The integral term calculation unit performs integral term calculation processing, and a voltage drop Vzqi representing a voltage command value of the integral term based on the current deviation δiq and the integral term calculation gain Giq.
Vzqi = Giq · ΣΔiq
Is calculated as an integral term operation value. Further, the voltage drop calculation adder performs a voltage drop calculation process, adds the voltage drops Vzqp and Vzqi, and then adds the voltage drop Vzq.
Vzq = Vzqp + Vzqi
= Gpq (Lqd) · Δiq + Giq · ΣΔiq
Is calculated.

The interference term calculation unit 88 performs a second interference term calculation process, reads the angular velocity ω, the q-axis current command value iq ^*, and the static inductance Lqs, and reads the angular velocity ω, the q-axis current command value iq ^*, and the static inductance Lqs. Based on the induced voltage ed induced by the d-axis current id of the interference term
ed = −ω · Lqs · iq ^*
Is sent to the adder 85.

Subsequently, the adder 85 adds the voltage drop Vzd sent from the PI term calculation unit 82 and the induced voltage ed sent from the interference term calculation unit 88, and d-axis voltage command value vd ^* as an output voltage ^.
vd ^* = Vzd + ed
= Vzd-ω · Lqs · iq ^*
Is calculated. Further, the adder 90 adds the voltage drop Vzq sent from the PI term calculation unit 87 and the induced voltage eq sent from the interference term calculation unit 83, and a q-axis voltage command value vq ^* as an output voltage ^.
vq ^* = Vzq + eq
= Vzq + ω (Mif + Lds · id ^* )
Is calculated.

In this way, the d-axis voltage command value vd ^* is generated so that the current deviation δid becomes zero, the q-axis voltage command value vq ^* is generated so that the current deviation δiq becomes zero, and d The shaft voltage command value vd ^* and the q-axis voltage command value vq ^* are sent to the voltage control unit 62.

In the present embodiment, the d-axis current command value id ^* is used in calculating the induced voltage eq in the first interference term calculation process, and the induced voltage ed is calculated in the second interference term calculation process. In the calculation, the q-axis current command value iq ^* is used. In place of the d-axis current command value id ^* , the d-axis current command value id ^* is replaced by the q-axis current command value iq ^*. A q-axis current iq can be used.

By the way, a static inductance necessary for obtaining the magnetic flux required for the interference term is used for the interference term, and a change in the magnetic flux required for the proportional term gain is used for the PI term. Since the necessary dynamic inductance is used, the characteristics of the control system do not change depending on the drive state of the drive motor 31. Therefore, the drive motor 31 can be driven stably when the d-axis current command value id ^* and the q-axis current command value iq ^* change or the operation state of the drive motor 31 changes.

  In the present embodiment, a drive motor as an electric machine has been described. However, the present invention can be applied to a generator as an electric machine. Further, although an electric vehicle as an electric vehicle has been described, the present invention can be applied to a hybrid vehicle. In this case, the hybrid vehicle is provided with a drive motor as a first electric machine and a generator as a second electric machine.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is a block diagram of the electric current control part in embodiment of this invention. It is a conceptual diagram of the electric drive device in embodiment of this invention. It is a block diagram which shows the principal part of the drive motor control apparatus in embodiment of this invention. It is a figure which shows the maximum drive motor target torque map in embodiment of this invention. It is a figure which shows the 1st electric current command value map in embodiment of this invention. It is a figure which shows the 2nd electric current command value map in embodiment of this invention. It is a characteristic view of the drive motor in the embodiment of the present invention. It is a characteristic view of the static inductance in the embodiment of the present invention. It is a characteristic view of the dynamic inductance in the embodiment of the present invention. It is a figure which shows the use range of the parameter in embodiment of this invention. It is a figure which shows the 1st inductance map in embodiment of this invention. It is a figure which shows the 2nd inductance map in embodiment of this invention.

Explanation of symbols

31 drive motor 45 drive motor control device 53 d-axis current command value calculation unit 54 q-axis current command value calculation unit 78, 79 voltage command value calculation unit 84, 89 inductance calculation unit

Claims (5)

  Current command value calculation processing means for calculating a current command value based on an electric machine target torque representing a target value of the torque of the electric machine, a voltage speed ratio calculated by dividing a DC voltage by an angular velocity, and an electric machine target torque And a voltage command value calculation processing unit for calculating a voltage command value based on the current command value and the inductance. The parameter calculation process means, an electric drive control apparatus according to claim 1 for calculating a first, second inductance change amount are different from each other when the current is changed. The electric drive control device according to claim 2 , wherein the first inductance is a value obtained by dividing magnetic flux by current. The electric drive control device according to claim 2 , wherein the second inductance is a value obtained by differentiating magnetic flux with current.   Calculate the current command value based on the electric machine target torque that represents the target value of the electric machine torque, and calculate the inductance based on the voltage speed ratio calculated by dividing the DC voltage by the angular speed and the electric machine target torque. A voltage command value is calculated based on the current command value and the inductance.

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