JP4715576B2 - 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.

  2. Description of the Related Art Conventionally, a drive motor or a generator disposed as an electric machine in an electric vehicle such as an electric vehicle or a hybrid vehicle includes a magnetic pole pair that is rotatably disposed and includes N-pole and S-pole permanent magnets. A rotor, a stator provided with U-phase, V-phase, and W-phase stator coils, and the like are disposed radially outward from the rotor.

  For example, an electric drive device is provided to drive the drive motor and generate a drive motor torque that is a torque of the drive motor. Also, a drive motor control device as an electric machine control device is provided to control the drive motor, and U-phase, V-phase, and W-phase pulse width modulation signals generated in the drive motor control device are invertered. So as to perform asynchronous PWM control by supplying phase currents generated in the inverter, that is, U-phase, V-phase and W-phase currents, to the respective stator coils to generate the drive motor torque. It has become.

  By the way, in the drive motor, a counter electromotive force is generated as the rotor rotates, and the higher the drive motor rotation speed, which is the rotation speed of the drive motor, the higher the terminal voltage of the drive motor or generator, When the terminal voltage exceeds the threshold value, voltage saturation occurs and output by the drive motor becomes impossible.

  Therefore, the modulation factor is calculated as a value representing the degree of voltage saturation, and when the modulation factor exceeds the maximum modulation factor for representing the theoretical maximum voltage, that is, when the maximum modulation factor is exceeded, the field weakening control region is entered. Judgment is made to perform field-weakening control. Therefore, a current command value map is formed, and in a predetermined region where the drive motor rotation speed is high in the current command value map, the d-axis current command value is increased in the negative direction, and the driving motor operating region is expanded, The drive motor torque is increased.

  Further, in the asynchronous PWM control, an asynchronous PWM signal is generated with a sine wave PWM pattern or an overmodulation PWM pattern. However, there is an upper limit on the amplitude of the voltage of each phase that can be applied to each stator coil. If an attempt is made to apply a voltage exceeding the value, in the proportional / integral calculation, the calculation of the voltage command value cannot follow the fluctuation of the current command value, and the voltage command value vibrates.

  Therefore, it is possible to switch between the asynchronous PWM control and the one-pulse control with one pulse, and when the modulation rate is equal to or less than the maximum modulation rate, the asynchronous PWM signal is expressed by a sine wave PWM pattern or an overmodulation PWM pattern. Asynchronous PWM control is performed, and when the modulation rate exceeds the maximum modulation rate, a synchronous PWM signal is generated with a one-pulse pattern to perform rectangular wave voltage control (see, for example, Patent Document 1). ).

  However, in the rectangular wave voltage control, when a synchronous PWM signal is generated with a one-pulse pattern, a voltage can be applied exceeding the upper limit of the amplitude of the voltage, but when switching between asynchronous PWM control and one-pulse control, shock occurs in the electric driving device by harmonic components included in the synchronous PWM signal for one pulse pattern.

Therefore, when switching from asynchronous PWM control to one-pulse control, a synchronous PWM signal is generated with a five-pulse pattern with a small harmonic component, and then a synchronous PWM signal with a one-pulse pattern is generated.
JP-A-6-78558

  However, in the conventional drive motor control device, in the region where the modulation rate takes a value near the maximum modulation rate, 1-pulse control by 1-pulse pattern and multi-pulse control by 5-pulse pattern chatter and control Will become unstable.

  The present invention provides an electric drive control apparatus and an electric drive control method capable of solving the problems of the conventional drive motor control apparatus and preventing the control from becoming unstable when performing field-weakening control. For the purpose.

  For this purpose, in the electric drive control device of the present invention, based on the current command value, current command value calculation processing means for calculating a current command value based on the electric machine target torque representing the target value of the torque of the electric machine. Voltage command value calculation processing means for calculating a voltage command value, modulation rate calculation processing means for calculating a modulation factor based on the voltage command value, and a modulation factor for calculating a modulation factor command value representing the command value of the modulation factor Command value calculation processing means is provided, a field weakening current is calculated based on the modulation factor and the modulation factor command value calculated by the modulation factor command value calculation processing means, and field weakening control is performed based on the field weakening current Field-weakening control processing means for performing.

  The modulation factor command value calculation processing means changes the modulation factor command value in accordance with the field weakening current.

  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 on the basis of the current command value Voltage command value calculation processing means for calculating a voltage command value, modulation rate calculation processing means for calculating a modulation factor based on the voltage command value, and a modulation factor for calculating a modulation factor command value representing the command value of the modulation factor Command value calculation processing means is provided, a field weakening current is calculated based on the modulation factor and the modulation factor command value calculated by the modulation factor command value calculation processing means, and field weakening control is performed based on the field weakening current Field-weakening control processing means for performing.

  The modulation factor command value calculation processing means changes the modulation factor command value in accordance with the field weakening current.

  In this case, by changing the modulation rate command value in accordance with the field weakening current, the timing for shifting from asynchronous PWM control or multi-pulse control to one-pulse control is different from the timing for starting field weakening control. be able to. Therefore, the one-pulse control and the asynchronous PWM control or the multi-pulse control are not chattered, and it is possible to prevent the control from becoming unstable.

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

FIG. 1 is a block diagram showing a main part of a drive motor control device in an embodiment of the present invention, FIG. 2 is a conceptual diagram of an electric drive device in an embodiment of the present invention, and FIG. 3 is a maximum in the embodiment of the present invention. FIG. 4 is a diagram showing a drive motor target torque map, FIG. 4 is a diagram showing a first current command value map in the embodiment of the present invention, and FIG. 5 is a diagram showing a second current command value map in the embodiment of the present invention. FIG. 6 is a diagram for explaining the voltage mode switching process in the embodiment of the present invention, FIG. 7 is a flowchart showing the operation of the modulation factor command value calculation processing unit in the embodiment of the present invention, and FIG. It is a figure which shows the operation | movement of the modulation factor command value calculation process part in the form. In FIG. 3, the horizontal axis represents the angular velocity ω, the vertical axis represents the maximum drive motor target torque TMmax ^* representing the maximum value of the drive motor target torque TM ^* , and in FIG. 4, the horizontal axis represents the drive motor target torque TM ^* . The vertical axis represents the d-axis current command value id ^* , the horizontal axis represents the d-axis current command value id ^* , the vertical axis represents the q-axis current command value iq ^* , and the horizontal axis in FIG. 6 represents the drive motor. In FIG. 8, the rotation speed NM, the voltage amplitude | v | on the vertical axis, the field weakening current Δid as the adjustment value on the horizontal axis, and the modulation rate command value on the vertical axis are taken. In this case, the electric machine torque is constituted by the drive motor torque TM which is the torque of the drive motor 31 as the electric machine, and the electric motor target torque is constituted by the drive motor target torque TM ^* representing the target value of the drive motor torque TM.

  In FIG. 2, 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 a radial direction from the rotor. A stator disposed outward is provided. 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 arranged 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, It is sent to a drive motor control device 45 as a machine 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 electric motor by driving the drive motor 31, a direct current from the battery 14 is converted into phase currents by the inverter 40 as a current generator, that is, U-phase, V-phase and W-phase currents. It is converted into Iu, Iv, and Iw, and the currents Iu, Iv, and Iw of each phase 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. 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 drive motor controller 45.

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 the torque command value limiter 22 as torque command value limit processing means. 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, and first phase conversion processing means The three-phase / two-phase converter 49 and the PWM generator 50 as output signal generation processing means are 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 calculation 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 serves as a modulation rate command value calculation processing unit and a modulation rate command value calculation unit 57 as a timing adjustment processing unit and a voltage saturation index calculation processing unit in order to perform field weakening control processing. And a d-axis current adjustment control unit 59 as a field weakening current calculation processing unit as a voltage saturation determination processing unit, and performs a field weakening control process so that the DC voltage Vdc (or battery voltage) is When the angular velocity ω (or drive motor rotational speed NM) increases, field weakening control is automatically performed. The d-axis current adjustment control unit 59 is configured by an integrator.

  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 calculation processing unit and a voltage control processing unit in order to perform a voltage command value setting process. of, and comprises a voltage control unit 62 as a second phase conversion processing means.

The current control unit 61 performs current control processing and shaft voltage command value calculation processing to calculate a d-axis voltage command value vd ^* and a q-axis voltage command value vq ^* as first and second shaft voltage command values. . The voltage control unit 62 is a first voltage command value calculation processing unit, a voltage amplitude calculation unit 63 as a modulation factor calculation processing unit, a second voltage command value calculation processing unit, and A voltage phase angle calculation unit 64 as voltage phase angle calculation processing means and an adder 65 as voltage phase angle conversion processing means are provided. The voltage control unit 62 performs voltage control processing, converts the d-axis voltage command value vd ^* and the q-axis voltage command value vq ^*, and converts the modulation factor (voltage amplitude) as the first and second voltage command values. Index) m and voltage phase angle γ are calculated. The d-axis voltage command value vd ^* and the q-axis voltage command value vq ^* constitute first and second axis voltage command values.

  The PWM generator 50 includes an overmodulation PWM pattern generation unit 72 as an overmodulation PWM pattern generation processing unit and a sine wave PWM pattern generation unit as a sine wave PWM pattern generation processing unit in order to perform an output signal generation process. 73, 5-pulse pattern generation unit 74 as first pulse pattern generation processing means and as multi-pulse pattern generation processing means, second pulse pattern generation processing means and as 1 pulse pattern generation processing means 1 pulse pattern generation unit 75 and voltage mode switching unit 77 as voltage mode switching processing means, and the first to fourth patterns of overmodulation PWM pattern, sine wave PWM pattern, five pulse pattern and one pulse pattern. selecting one pattern of out, each phase of the asynchronous PWM signal in the selected pattern The pulse width modulation signals Mu as synchronous PWM signal, Mv, is generated as an output signal a Mw, sends it 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 ^* .

Therefore, when the drive motor target torque TM ^* is sent from the vehicle command value calculation processing means to the drive motor control device 45, the torque command value limiting unit 22 performs a torque command value limiting process, and the DC voltage Vdc. , Read the angular velocity ω and the drive motor target torque TM ^* , refer to the maximum drive motor target torque map of FIG. 3 set in the recording device, and refer to the maximum drive motor target torque TMmax ^* corresponding to the DC voltage Vdc and the angular velocity ω ^. Is limited so that the drive motor target torque TM ^* does not exceed the maximum drive motor target torque TMmax ^* .

In the 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 predetermined value ω1, the maximum drive motor target torque. TMmax ^* is reduced in a curved line. In the region where the angular velocity ω exceeds the predetermined value ω1, the maximum drive motor target torque TMmax ^* is set to be 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 ^* .

Subsequently, 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 ^* limited by the torque command value limit unit 22, Referring to the first current command value map shown in FIG 4 that is set in the recording apparatus reads out the target drive motor torque TM ^* d-axis current command value corresponding to the id ^*, the d-axis current command value id ^* This is sent to the subtracter 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 value, whereas the d-axis current command value id ^* takes a negative value, and the drive motor target torque TM ^* is In the case of zero (0), the d-axis current command value id ^* is set to zero, and the d-axis current command value id ^* is set to increase in the negative direction as the drive motor target torque TM ^* increases.

When the d-axis current command value id ^* is calculated in this way, the q-axis current command value calculation unit 54 determines the drive motor target torque TM ^* limited by the torque command value limiting unit 22 and the weakening field. reads the current .DELTA.id, as previously described, with reference to the first current command value map, reads the d-axis current command value id ^* corresponding to the drive motor target torque TM ^*, subsequently, to the recording device It refers to the set second electric current command value map in FIG. 5, is calculated by reading the q-axis current command value iq ^* corresponding to the target drive motor torque TM ^* and the d-axis current command value id ^*, the q The shaft current command value iq ^* is sent to the current control unit 61.

In the second current command value map, as the drive motor target torque TM ^* increases, the d-axis current command value id ^* increases in the negative direction and the q-axis current command value iq ^* increases in the positive direction. The smaller the motor target torque TM ^* , the smaller the d-axis current command value id ^* is set in the negative direction, and the q-axis current command value iq ^* is set in the positive direction. Further, 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 direction.

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

The three-phase / two-phase converter 49 performs three-phase / two-phase conversion as 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, respectively. iq, d-axis current id and q-axis current iq are calculated as actual currents and sent to current control unit 61. Then, the current control unit 61 sends the d-axis current command value id ^* sent from the d-axis current command value calculation unit 53 via the subtractor 55 and the q-axis current command sent from the q-axis current command value calculation unit 54. When the value iq ^* is received and the d-axis current id and the q-axis current iq are received from the three-phase / two-phase converter 49, feedback control is performed.

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, a proportional-integral calculation including proportional control and integral control is performed.

That is, the current control unit 61 calculates a voltage drop Vzdp representing the voltage command value of the proportional component and a voltage drop Vzdi representing the voltage command value of the integral component based on the current deviation δid, and adds the voltage drops Vzdp and Vzdi. The voltage drop Vzd
Vzd = Vzdp + Vzdi
Is calculated.

The current controller 61 reads the angular velocity ω and the q-axis current iq, and the induced voltage ed induced by the q-axis current iq based on the angular velocity ω, the q-axis current iq, and the q-axis inductance Lq.
ed = ω ・ Lq ・ iq
And the induced voltage ed is subtracted from the voltage drop Vzd to obtain a d-axis voltage command value vd ^* as an output voltage ^.
vd ^* = Vzd-ed
= Vzd-ω · Lq · iq
Is calculated.

Further, the current control unit 61 calculates a voltage drop Vzqp representing the voltage command value of the proportional component and a voltage drop Vzqi representing the voltage command value for the integral term based on the current deviation δiq, and adds the voltage drops Vzqp and Vzqi. The voltage drop Vzq
Vzq = Vzqp + Vzqi
Is calculated.

Further, the current control unit 61 reads the angular velocity ω and the d-axis current id, and an induced voltage induced by the d-axis current id based on the angular velocity ω, the counter electromotive voltage constant MIf, the d-axis current id, and the d-axis inductance Ld. eq
eq = ω (Mif + Ld · id)
And the induced voltage eq is added to the voltage drop Vzq, and the q-axis voltage command value vq ^* as the output voltage is calculated ^.
vq ^* = Vzq + eq
= Vzq + ω (Mif + Ld · id)
Is calculated.

Subsequently, the voltage controller 62 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, and the voltage phase angle on the modulation factor m and dq coordinates. γ is calculated, the voltage phase angle γ is converted into a voltage phase angle β on a fixed coordinate, and the modulation factor m and the voltage phase angle β are sent to the PWM generator 50.

  Therefore, the voltage amplitude calculator 63 performs modulation factor calculation process, voltage amplitude | v |

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

Is sent to the PWM generator 50. The modulation factor m is a value representing the degree of voltage saturation. In addition, the voltage phase angle calculation unit 64 is configured such that the voltage phase angle γ on the dq coordinate is
γ = arctan (vq ^* / vd ^* )
Is calculated and sent to the adder 65. The adder 65 performs voltage phase angle conversion processing, adds the magnetic pole position θ to the voltage phase angle γ, and outputs the voltage phase angle β on the fixed coordinates.
β = γ + θ
Is sent to the PWM generator 50.

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

  In the drive motor 31, a counter electromotive force is generated as the rotor rotates. The higher the drive motor rotational speed NM, the higher the terminal voltage of the drive motor 31, and the terminal voltage exceeds the threshold value. When, voltage saturation occurs, the output by the drive motor 31 becomes impossible.

Therefore, 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 the modulation factor command value calculation unit 57, that is, a modulation factor command value k. Voltage saturation index Δm, which is an index representing the degree of voltage saturation
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. A 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 set to zero.

The field weakening current Δid is sent to the modulation factor command value calculating unit 57, the q-axis current command value calculating unit 54, and the subtractor 55. When the subtractor 55 receives the field weakening current Δid, the current command performs value adjustment process, the d-axis current command value by adjusting the d-axis current command value id ^* by subtracting the field weakening current Δid from id ^*, adjusted d-axis current command value id ^* of the current controller Send to 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. 5, 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 the 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, the d-axis current command value id ^* is only the field weakening current Δid in the negative direction. The large value idb ^* is set, and the value idb ^* is sent to the q-axis current command value calculation unit 54. 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 ^*.

  By the way, as described above, when the PWM generator 50 receives the modulation factor m and the voltage phase angle β, the PWM generator 50 performs output signal generation processing, and performs an overmodulation PWM pattern, a sine wave PWM pattern, a five-pulse pattern, and a one-pulse pattern. One of these patterns is selected, and pulse width modulation signals Mu, Mv, and Mw of each phase are generated with the selected pattern. In the present embodiment, a plurality of (odd number) first pulse patterns consisting of five pulses are constituted by the five pulse patterns, and a second pulse pattern consisting of one pulse is constituted by one pulse pattern. Is configured.

  Next, the operation of the PWM generator 50 will be described.

  In this case, as shown in FIG. 6, in the area AR1 where the voltage amplitude | v | is lower than the first value v1, the voltage mode switching unit 77 performs the voltage mode switching process, and the sine wave PWM pattern generation unit 73. The asynchronous PWM signal of the sine wave PWM pattern generated in step 1 is received and sent to the drive circuit 51. The area AR1 constitutes a sine wave area.

  Therefore, the sine wave PWM pattern generation unit 73 performs a sine wave PWM pattern generation process, receives the modulation factor m and the voltage phase angle β, and generates a sine wave of each phase based on the modulation factor m and the voltage phase angle β. Comparing the sine wave with a triangular wave oscillating at a constant frequency and a constant amplitude to generate a pulse width modulation signal Mu, Mv, Mw comprising a plurality of pulses having unequal pulse widths, width modulation signals Mu, Mv, sends the Mw to the voltage mode switching part 77. In this manner, asynchronous PWM control is performed based on the asynchronous PWM signal generated with the sine wave PWM pattern. In the area AR1, when the drive motor rotation speed NM exceeds the allowable value N2, the allowable voltage amplitude | v | is decreased, and when the drive motor rotation speed NM reaches the limit value N3, the allowable voltage is reduced. The value of the amplitude | v | is made zero.

  By the way, when the asynchronous PWM signal is generated, the voltage of each phase is applied to each of the stator coils 11 to 13, but the voltage amplitude | v | of the voltage of each phase has an upper limit. When you try to apply a vibration is generated in the modulation factor m and the voltage phase angle beta.

  Therefore, when the voltage amplitude | v | becomes equal to or greater than the first value v1, the overmodulation region determination processing means (not shown) of the voltage mode switching unit 77 performs overmodulation region determination processing, and the voltage amplitude | v | It is determined whether or not the value is greater than or equal to the value v1 and lower than the second value V2, and the drive motor rotational speed NM falls within the area AR2 that is lower than the predetermined value N1, and the voltage amplitude | v | Is received in the area AR2, the asynchronous PWM signal of the overmodulation PWM pattern generated by the overmodulation PWM pattern generator 72 is received and sent to the drive circuit 51. The area AR2 constitutes an overmodulation area. The first value v1 is the maximum value of the voltage amplitude | v | when generating an asynchronous PWM signal with a sine wave PWM pattern, and the second value v2 is when generating a synchronous PWM signal with one pulse pattern. Is the maximum value of the voltage amplitude | v |.

  Then, the overmodulation PWM pattern generation unit 72 performs an overmodulation PWM pattern generation process in the area AR2, and based on the voltage phase angle β, a portion of each phase equal to or greater than the first value v1, that is, the peak value of the sine wave Is generated, a sine wave is cut, and the sine wave is compared with a triangular wave oscillating at a constant frequency and a constant amplitude, and a pulse width modulation signal Mu composed of a plurality of pulses having unequal pulse widths, Mv and Mw are generated, and the pulse width modulation signals Mu, Mv and Mw are sent to the voltage mode switching unit 77. In this manner, asynchronous PWM control is performed based on the asynchronous PWM signal generated with the overmodulation PWM pattern.

  By the way, since the timing of switching by the transistors Tr1 to Tr6 of the inverter 40 is not synchronized with the voltage phase angle β, when the drive motor 31 is driven in the high speed rotation region, the voltage of each phase is changed. Vibration occurs and the beat phenomenon appears.

  Therefore, it is possible to switch between the asynchronous PWM control using the asynchronous PWM signal and the synchronous PWM control using the synchronous PWM signal, and the medium-speed rotation region where the drive motor rotational speed NM is lower than the value N1, such as the region AR2. In the low speed rotation region, asynchronous PWM control is performed by generating an asynchronous PWM signal with an overmodulation PWM pattern, the voltage amplitude | v | is equal to or greater than the first value v1, and the drive motor rotational speed NM is equal to or greater than the value N1. In the high-speed rotation region, the synchronous PWM signal is generated with one pulse pattern consisting of one pulse within the range of ± 180 [°] at the maximum, for example, ± 90 [°] around the origin at the electrical angle. Te, and to perform the 1-pulse control of the synchronous PWM control.

  However, in the rectangular wave voltage control, when a synchronous PWM signal is generated with one pulse pattern, a voltage can be applied exceeding the upper limit of the amplitude of the voltage applied to each of the stator coils 11 to 13. When the asynchronous PWM control by the sine wave PWM pattern is performed in AR1, the voltage amplitude | v | is equal to or larger than the first value v1, or the asynchronous PWM control by the overmodulation PWM pattern is performed. If the drive motor rotational speed NM exceeds the value N1 and directly shifts to one-pulse control, a shock is generated in the electric drive device due to the harmonic component included in the synchronous PWM signal of one-pulse pattern.

  Therefore, the asynchronous / synchronous switching processing unit (not shown) of the voltage mode switching unit 77 performs the asynchronous / synchronous switching process, and when switching from the asynchronous PWM control to the synchronous PWM control, the voltage amplitude | v | is greater than or equal to the first value v1. In addition, it is determined whether it falls within the area AR3 that is lower than the second value v2 and the drive motor rotational speed NM is equal to or greater than the value N1, and the voltage amplitude | v | and the drive motor rotational speed NM fall within the area AR3. In this case, a synchronous PWM signal of a pulse pattern composed of a plurality of pulses, in this embodiment, a synchronous PWM signal of a 5-pulse pattern generated by the 5-pulse pattern generation unit 74 is received and sent to the drive circuit 51.

  Therefore, the 5-pulse pattern generation unit 74 performs a first pulse pattern generation process and a 5-pulse pattern generation process, receives the modulation factor m and the voltage phase angle β, and based on the modulation factor m and the voltage phase angle β. A 5-pulse pattern synchronous PWM signal having 5 pulses within a range of ± 180 [°] around the origin is generated. In this way, 5 pulse control of the synchronization control, namely, it is possible to perform multi-pulse control.

  In order to eliminate the change in the voltage applied to each of the stator coils 11 to 13 when the 5-pulse pattern generation process is completed and when the 1-pulse pattern generation process is started, a 3-pulse pattern generation unit is provided. It is possible to generate a three-pulse pattern synchronous PWM signal having three pulses by the three-pulse pattern, and shift from the five-pulse pattern to the one-pulse pattern via the three-pulse pattern.

By the way, if the first value v1 is the theoretical maximum voltage Vmax, the maximum modulation rate kmax where the modulation factor m represents the maximum value of the modulation factor m.
kmax = 1
When the value exceeds the value, the asynchronous PWM control by the sine wave PWM pattern or the 5-pulse control is shifted to the 1-pulse control. When field weakening control is started when the modulation factor m exceeds the maximum modulation factor kmax, the 1-pulse control and the 5-pulse control chatter and the control becomes unstable.

  Therefore, in the present embodiment, the modulation rate command value calculation unit 57 performs modulation rate command value calculation processing and timing adjustment processing, changes the modulation rate command value k in the vicinity of the maximum modulation rate kmax, and performs field weakening control. Is different from the timing at which the asynchronous PWM control by the sine wave PWM pattern or the transition from the 5-pulse control to the 1-pulse control is started.

  Therefore, as shown in FIG. 8, the modulation factor command value k includes a lower limit value k1 as a first value smaller than the maximum modulation factor kmax, and an upper limit value k2 as a second value larger than the maximum modulation factor kmax. Is set to the field weakening current Δi, a first threshold value Δi1 larger than zero in the positive direction and a second threshold value Δi2 larger than the first threshold value.

Then, the field weakening current determination processing means (not shown) of the modulation factor command value calculation unit 57 performs field weakening current determination processing and reads the field weakening current Δid. Subsequently, the modulation factor command value calculation processing unit 57 of the modulation factor command value calculation unit 57 determines that the field weakening current Δid is
Δid = 0
, The modulation factor command value k is
k = k1
And the field weakening current Δid is
0 <Δid <Δi1
, The modulation factor command value k is
k1 <k <kmax
And the field weakening current Δid is
Δid = Δi1
, The modulation factor command value k is
k = kmax
To. Further, the modulation factor command value calculation processing means is configured so that the field weakening current Δid is
Δi1 <Δid <Δi2
, The modulation factor command value k is
kmax <k <k2
And the field weakening current Δid is
Δid ≧ Δi2
, The modulation factor command value k is
k = k2
To.

Then, a third threshold value Δi3 larger than zero and smaller than the first threshold value Δi1 is set, and the field weakening current Δid is
Δi3 <Δid <Δi1
Thus, hysteresis is set between 5-pulse control and 1-pulse control.

  Therefore, when the field weakening current Δid is equal to or greater than the first threshold value Δi1, the transition from the 5-pulse control to the one-pulse control is performed, and when the field weakening current Δid is equal to or less than the third threshold value Δi3, Transition to 5-pulse control is performed.

The field weakening current Δid is
0 ≦ Δid ≦ Δi2
The modulation factor command value k can be expressed by the following equation.

k = kmax−α (1−Δid / Δi1)
Here, α is the slope of the line representing the modulation factor command value k, and can be represented by the following equation.

α = (k2−k1) / Δi2
In this case, the modulation factor command value k can be changed linearly with respect to the field weakening current Δid, but it can be changed stepwise or changed to a curve represented by a predetermined function. Can be.

  Thus, in the present embodiment, the field weakening control is started when the modulation factor command value k takes a value smaller than the maximum modulation factor max, and the timing at which the field weakening control is started and the asynchronous PWM based on the sine wave PWM pattern. The timing for shifting to control and 5-pulse control is made different. Therefore, chattering from asynchronous PWM control to 5-pulse control is eliminated, and control can be stabilized.

  Similarly, the timing at which the field weakening control is ended and the timing at which the 5-pulse control is shifted to the asynchronous PWM control using the sine wave PWM pattern are also made different.

Next, a flowchart will be described.
Step S1: It is determined whether or not the field weakening current Δid is zero. If the field weakening current Δid is zero, the process proceeds to step S4. If the field weakening current Δid is not zero, the process proceeds to step S2.
Step S2: It is determined whether the field weakening current Δid is smaller than the second threshold value Δi2. When the field weakening current Δid is smaller than the second threshold value Δi2, the process proceeds to step S5, and when the field weakening current Δid is equal to or larger than the second threshold value Δi2, the process proceeds to step S3.
Step S3: The modulation factor command value k is set to a value larger than the lower limit value k1 and smaller than the upper limit value k2, and the process ends.
Step S4: The lower limit value k1 is set to the modulation factor command value k, and the process is terminated.
Step S5: The upper limit value k2 is set to the modulation factor command value k, and the process is terminated.

  Although the case where the drive motor 31 is driven is described in the present embodiment, the present invention is applied to the case where the generator as the electric machine is driven, the drive motor as the first electric machine, and the second. This can be applied to driving a generator as an 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.

The main part of the driving motor control unit according to the embodiment of the present invention is a block diagram showing. It is a conceptual diagram of the electric drive device 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 diagram showing a first current command value map in the embodiment of the present invention. It is a diagram illustrating a second electric current command value map in the embodiment of the present invention. It is a figure explaining the voltage mode switching process in embodiment of this invention. Is a flowchart showing the operation of the modulation rate instruction value calculation processing section in an embodiment of the present invention. Is a diagram showing an operation of the modulation rate instruction value calculation processing unit in the embodiment of the present invention.

Explanation of symbols

31 drive motor 47 field weakening control unit 53 d-axis current command value calculation unit 54 q-axis current command value calculation unit 55 subtractor 57 modulation factor command value calculation unit 63 voltage amplitude calculation unit 64 voltage phase angle calculation unit 77 voltage mode switching unit

Claims (5)

Current command value calculation processing means for calculating a current command value based on the electric machine target torque representing the target value of the torque of the electric machine;
Voltage command value calculation processing means for calculating a voltage command value based on the current command value;
Modulation rate calculation processing means for calculating a modulation rate based on the voltage command value;
A modulation factor command value calculation processing means for calculating a modulation factor command value representing a command value of the modulation factor, the modulation rate, and weakened on the basis of the modulation rate instruction value calculated by the modulation rate instruction value calculation processing means A field weakening control processing means for calculating a field current and performing field weakening control based on the field weakening current,
The modulation rate command value calculation processing means changes the modulation rate command value in accordance with the field weakening current.   When the field weakening current is smaller than the threshold, the modulation factor command value calculation processing means makes the modulation factor command value smaller than the maximum modulation rate, and when the field weakening current is equal to or greater than the threshold, The electric drive control device according to claim 1, wherein the electric drive control device is set to a maximum modulation rate or more. Current command value calculation processing means for calculating a current command value based on the electric machine target torque representing the target value of the torque of the electric machine;
Voltage command value calculation processing means for calculating a voltage command value based on the current command value;
Modulation rate calculation processing means for calculating a modulation rate based on the voltage command value;
Voltage mode switching processing means for shifting from asynchronous PWM control or multi-pulse control to one-pulse control based on the modulation rate;
Modulation rate command value calculation processing means for calculating a modulation rate command value representing the modulation rate command value , and weakening based on the modulation rate and the modulation rate command value calculated by the modulation rate command value calculation processing means. A field weakening control processing means for calculating a field current and performing field weakening control based on the field weakening current,
The modulation factor command value calculation processing means changes the modulation factor command value in accordance with the field weakening current , and starts the field weakening control when the asynchronous PWM control or the transition from the multi-pulse control to the one-pulse control is performed. electric drive control device comprising a benzalkonium made different from the timing. Before SL modulation rate instruction value calculation processing means, the maximum modulation rate and smaller than the first value, the electric drive control apparatus according to claim 3 for varying the modulation factor between the second value greater than the maximum modulation factor . A current command value is calculated based on the electric machine target torque representing the target value of the electric machine torque,
Calculate a voltage command value based on the current command value,
Calculate the modulation factor based on the voltage command value,
A modulation factor command value representing the modulation factor command value is calculated, a field weakening current is calculated based on the modulation factor and the calculated modulation factor command value, and field weakening control is performed based on the field weakening current. With
The electric drive control method, wherein the modulation factor command value is changed in accordance with a field weakening current.

Images