JP2010183661A - Rotating electrical machine control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a d-axis current value from going out of a normal control range, when performing rectangular wave voltage phase control, in a rotating electrical machine control system. <P>SOLUTION: In a rectangular wave voltage phase control mode, the control system performs torque feedback wherein it converts each phase current value of a rotating electrical machine 20 into a dq current value in a coordinate converter 72, and computes a torque estimate from the dq current value in a torque estimator 76, via a primary delay processor 74, and feeds it back to the torque command value. In addition to this main feedback loop, the control system is provided with a loop for getting a time constant τ corresponding to a torque deviation ΔT at the timing of each control operation cycle by using a table 86 which shows the relation of the time constant τ to the torque deviation ΔT, and applying the response property 88 of the primary delay based on the time constant τ to a primary delay processor 74. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine control system, and more particularly to a rotating electrical machine control system in which torque feedback is performed.

  When the rotating electrical machine is driven by an inverter, a sine wave current control mode, an overmodulation current control mode, and a rectangular wave voltage phase control mode are selectively used as a control method. That is, in order to achieve both high output and miniaturization of the rotating electrical machine, a rectangular wave voltage phase control mode using one-pulse switching is necessary, and a sine wave current control mode having excellent characteristics in a low speed region, The rotating electrical machine is optimally controlled while switching the mode between the overmodulation current control mode used in the medium speed region.

  Here, the sine wave current control mode and the overmodulation current control mode are current feedback control, and a pulse width modulation (PWM) pattern is changed by comparing a voltage command with a carrier wave (carrier). It is the control which outputs to. On the other hand, the rectangular wave voltage phase control mode is a control for outputting a one-pulse switching waveform to the rotating electrical machine according to the electrical angle. The voltage amplitude is fixed to the maximum value, and the torque is feedback controlled by controlling the phase. Yes.

  Switching between the three modes of the sine wave current control mode to the overmodulation current control mode and the overmodulation current control mode to the rectangular wave voltage phase control mode is performed according to the modulation rate or the voltage command amplitude corresponding to the modulation rate. The switching from the rectangular wave voltage phase control mode to the overmodulation current control mode is performed by determining the switching timing based on the phase of the actual current with respect to the current command because the voltage command amplitude is constant in the rectangular wave voltage phase control mode. Done.

  For example, in Patent Document 1, as an AC motor drive control device, when the voltage amplitude exceeds 1.00 times the peak value of the reference triangular wave, the PWM current control mode is switched to the overmodulation control mode, and the voltage amplitude is the reference triangular wave. Switching to rectangular wave voltage phase control mode when the peak value exceeds 1.27 times, while switching from rectangular wave voltage phase control mode to overmodulation control mode when the absolute value of the actual current phase is less than the absolute value of the current command phase The inverter receives a switching command from the PWM current control unit, a switching command from the overmodulation control unit, or a rectangular wave voltage from the rectangular wave voltage phase control unit, and generates a three-phase pseudo sine wave signal Is stated.

Since the d-axis current and the q-axis current include periodic noise and harmonics, the measurement current is subjected to low-pass filter processing. For this filter processing, the rectangular wave voltage phase control mode is changed to the overmodulation control mode. It has been pointed out that control of the control becomes uneasy due to delaying of switching of the current, causing hunting of the current phase and the like. Therefore, here, by comparing the required voltage amplitude V _R taking into account the induced voltage and the like and the peak value of the reference triangular wave, and providing an offset value that does not cause chattering, it is possible to overmodulate from the rectangular wave voltage phase control mode. It is disclosed that there is no delay in switching to the control mode.

  Further, in Patent Document 2, as a power output device, the time constant used for the smoothing process for torque limitation of the motor MG2 is small when the power generation change amount of the motor MG1 is large and large when the power generation change amount is small. It is disclosed. Accordingly, it is stated that even when the amount of power generated by the motor MG1 sharply decreases, it is possible to improve the followability with respect to the change in the torque limit of the motor MG2.

  Patent Document 3 discloses a power output device that performs a smoothing process on the power deviation obtained by subtracting the input / output power input / output to / from the battery and the assumed power input / output from / to the motor to allow the battery input / output allowable limit Is disclosed. Here, when the motor control mode is changed and within a predetermined time, the calculation of the input / output allowable limit can be performed quickly by making the smoothing processing time constant smaller than the normal value. It is stated.

  Further, in Patent Document 4, in the load driving device, the time constant of the first order calculation for the voltage command value of the boost converter is 20 ms in the PWM control mode, 50 ms in the overmodulation control mode, and the rectangular wave control mode. It is disclosed that the change rate of the voltage command value is changed according to the difference in the control timing of the control mode as 100 ms. Thus, it is stated that control can be prevented from failing in each control mode even if there is a sudden change in the input voltage to the inverter.

JP 2008-11682 A JP 2005-151620 A JP 2006-174567 A JP 2005-45880 A

  As described above, the sine wave current control mode, the overmodulation current control mode, and the rectangular wave voltage phase control mode are selectively used as a control method of the rotating electrical machine. Since waves are used, there is a problem that the d-axis current and the q-axis current include periodic noise and harmonics. In response to this, the prior art also describes performing a low-pass filter process on the measurement current.

  By performing this low-pass filter process, noise in the measurement current is removed, and the measurement accuracy is improved and the stability of the control is improved. On the other hand, the response is delayed. For example, when there is a demand for a large torque drop, the deviation of the torque command value suddenly changes, and the deviation is overestimated. It is possible to enter a positive region that is not within the normal control range beyond a certain negative region.

  An object of the present invention is to provide a rotating electrical machine control system capable of suppressing a d-axis current value from deviating from a normal control range in a rectangular wave voltage phase control mode.

  The rotating electrical machine control system according to the present invention generates a voltage phase command by performing a control to bring the calculated torque deviation close to zero by performing torque deviation calculating means that is a deviation between the torque command value and the torque estimated value, Deviation control means for supplying to the drive unit, dq current calculation means for calculating the d-axis current value and the q-axis current value based on each phase current value of the rotating electrical machine, the calculated d-axis current value and the q-axis Smoothing processing means for applying a first-order lag process with a predetermined time constant to the current value and outputting a processed d-axis current value and a processed q-axis current value; and a processed d-axis current value and a process A torque estimated value calculating means that calculates a torque estimated value based on the rear q-axis current value and supplies the torque estimated value to the torque deviation calculating means, and the smoothing processing means uses a time constant corresponding to the torque deviation. It is characterized in that next delay processing is performed.

  With the above configuration, the rotating electrical machine control system in which torque feedback is performed performs first-order lag processing with a predetermined time constant on the d-axis current value and the q-axis current value used to calculate the estimated torque value, At that time, a time constant corresponding to the torque deviation is used. Thus, for example, when the torque deviation is small, a normal time constant is used, and when the torque deviation is large, the time constant can be reduced to reduce the first order lag to ensure responsiveness. Can be calculated appropriately. Therefore, it is possible to suppress the deviation from being estimated excessively, and to prevent the d-axis current from deviating from the normal control range.

In embodiment which concerns on this invention, it is a figure which shows the structure of the rotary electric machine control system with respect to the rotary electric machine mounted in a vehicle. It is a figure explaining a mode that a control mode is selected according to the operating point of a rotary electric machine. It is a figure which shows the mode of a phase current waveform and an interphase voltage waveform about sine wave current control mode. It is a figure which shows the mode of a phase current waveform and an interphase voltage waveform about overmodulation current control mode. It is a figure which shows the mode of a phase current waveform and an interphase voltage waveform about a rectangular wave voltage phase control mode. It is a figure explaining the mode of the mode switching reference line in the embodiment according to the present invention. It is a control block diagram at the time of the rectangular wave voltage phase control in embodiment which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a vehicle equipped with a rotating electrical machine will be described as an example where the rotating electrical machine control system is used, but this is an example, and a sine wave current control mode, an overmodulation current control mode, a rectangular wave voltage phase control mode, and What is necessary is just to use the rotary electric machine control system which switches control between. In addition, this vehicle will be described as using two motor generators having a motor function and a generator function as a rotating electric machine, but this is an example and only the motor function One rotating electrical machine having a power generator and one rotating electrical machine having only a generator function may be used. Further, one motor / generator may be used, or three or more may be used.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram showing a configuration of a rotating electrical machine control system 10 for a rotating electrical machine mounted on a vehicle. The vehicle includes an engine 12 and a power storage device 14 as power sources, and includes a first rotating electrical machine (MG1) 18 and a second rotating electrical machine (MG2) 20, and further, the power storage device 14 and two rotating electrical machines 18. , 20 and a power distribution mechanism for performing power distribution among the power supply circuit 16, which is a converter / inverter connected between the engine 12, the engine 12, the first rotating electrical machine 18, and the second rotating electrical machine 20. 22, a transmission 24 provided between the power distribution mechanism 22 and the second rotating electrical machine 20, wheels or tires 26 that receive driving force from the transmission 24, and control that controls the operation of these elements as a whole. The unit 30 is provided.

  The rotating electrical machine control system 10 mainly corresponds to a part including the rotating electrical machines 18 and 20, the power supply circuit 16, and the control unit 30 among these components. Components other than these are elements that are often used in so-called hybrid vehicles and the like, and thus detailed description thereof is omitted.

  The first rotating electrical machine (MG1) 18 and the second rotating electrical machine (MG2) 20 are motor generators (MG) mounted on the vehicle, and function as motors when electric power is supplied from the power storage device 14. The three-phase synchronous rotating electric machine functions as a generator when driven by the engine 12 or when the vehicle is braked.

  Here, the first rotating electrical machine (MG1) 18 is used as a generator driven by the engine 12 and used to supply the generated power to the power storage device 14 via the converter / inverter of the power supply circuit 16. It is done. The second rotating electrical machine (MG2) 20 is used for running the vehicle, and receives AC power supplied from the power storage device 14 during power running and is converted by AC power converted through a converter / inverter of the power supply circuit 16. It functions as a motor to drive the vehicle tire 26 and functions as a generator during braking to collect regenerative energy and supply it to the power storage device 14 via the converter / inverter of the power supply circuit 16.

  As described above, the power supply circuit 16 is a circuit disposed between the power storage device 14 and the two rotating electrical machines 18 and 20, and includes a smoothing capacitor and the like in addition to a converter and an inverter.

  The converter included in the power supply circuit 16 is a circuit that is disposed between the power storage device 14 and the inverter and has a voltage conversion function. The converter can include a reactor and a switching element that operates under the control of the control unit 30. As the voltage conversion function, the voltage on the power storage device side is boosted using the reactor energy storage action and supplied to the inverter side, and the power from the inverter side is stepped down to the power storage device side and supplied as charging power It has a step-down function. When paying attention to the boost function, the converter can be called a boost circuit.

  The inverter included in the power supply circuit 16 is a circuit that performs power conversion between AC power and DC power. The inverter is configured to include a plurality of switching elements that operate under the control of the control unit 30. As described above, since the first rotating electrical machine (MG1) 18 and the second rotating electrical machine (MG2) 20 have different uses and operating point conditions, the inverter is configured with two inverter circuits therein. . One of the two inverter circuits is an inverter circuit for operating the first rotating electrical machine (MG1) 18, and the other is an inverter circuit for operating the second rotating electrical machine (MG2) 20.

  As described above, when the first rotating electrical machine (MG1) 18 is caused to function as a generator, the inverter circuit for operation thereof converts the AC three-phase regenerative power from the first rotating electrical machine (MG1) 18 into DC power. It has an AC / DC conversion function of converting and supplying the power storage device side as a charging current. Further, the inverter circuit for operation of the second rotating electrical machine (MG2) 20 converts the DC power from the power storage device side into AC three-phase driving power when the vehicle is in power running, and the second rotating electrical machine (MG2) 20 When the vehicle is braking, the AC three-phase regenerative power from the second rotating electrical machine (MG2) 20 is converted into DC power and supplied to the power storage device side as charging current. AC / DC conversion function.

  The control unit 30 has a function of controlling the operation of each element as a whole. For example, the function of controlling the operation of the engine 12, the function of controlling the operation of the rotating electrical machines 18 and 20, the function of controlling the operation of the power supply circuit 16, the function of controlling the operation of the power distribution mechanism 22, and the operation of the transmission 24. It has a function to control.

  The control unit 30 can be configured by a control device suitable for mounting on a vehicle, for example, a vehicle-mounted computer. Although the control unit 30 can be configured by a single computer, a plurality of computers can also share these functions in consideration of the difference in required processing speed depending on each component. For example, the function of controlling the operation of the engine 12 is shared by an engine electrical control unit (ECU), and the function of controlling the operations of the two rotating electrical machines 18 and 20 is shared by the MG-ECU. A function of controlling the operation of the PCU (Power Control Unit) may be shared and the whole may be controlled by an integrated ECU.

  In FIG. 1, the control unit 30 excessively generates an overshoot of the current value when switching from the rectangular wave voltage phase control mode to the overmodulation current control mode as a rotating electrical machine control function among these functions. The part which has the function for suppressing this is shown. In other words, the control unit 30 controls the rotating electrical machines 18 and 20 with a sine wave current control module 32 that executes the sine wave current control mode, an overmodulation current control module 34 that executes the overmodulation current control mode, and a rectangular wave voltage phase. A rectangular wave voltage phase control module 36 for executing the control mode is included.

In addition, when switching from the rectangular wave voltage phase control mode to the overmodulation current control mode, the current deviation determination module 40 and the switching time control module 42 are provided to prevent excessive overshoot of the current value. Consists of including.
Here, the current deviation determination module 40 has a function of determining whether or not the current deviation in the mode switching from the rectangular wave voltage phase control mode to the overmodulation current control mode exceeds a predetermined threshold deviation. Further, the switching control module 42 executes current feedback control under normal conditions when the current deviation is equal to or less than the threshold deviation, and when the current deviation exceeds the threshold deviation, a predetermined change with respect to time variation of the current deviation is predetermined. Current feedback control within a range equal to or less than the current deviation change rate.

The predetermined current change rate is preferably set to be equal to or less than the current deviation change rate obtained by dividing the current deviation in one electrical cycle of the rotating electrical machine.
These functions can be realized by executing software, and specifically, can be realized by executing a control mode switching part in the rotating electrical machine control program. Some of these functions may be realized by hardware.

  The operation of the above configuration, particularly each function of the control unit 30, will be described in detail below. Since the control of the two rotating electrical machines 18 and 20 is not particularly distinguished, switching of the control mode and the like will be described below as a representative example of the second rotating electrical machine 20.

  First, the proper use of the sine wave current control mode, overmodulation current control mode, rectangular wave voltage phase control mode, etc. will be described, and then the normal control range for vector control will be described using the dq plane. Subsequently, torque feedback control in the rectangular wave voltage phase control mode will be described, and details of control for preventing the d-axis current value from deviating from the normal control range by the annealing process will be described.

  The sine wave current control mode and the overmodulation current control mode are current feedback controls, and a pulse width modulation (PWM) pattern is output to the rotating electrical machine 20 by comparing a voltage command with a carrier wave (carrier). It is control to do. On the other hand, the rectangular wave voltage phase control mode is a control for outputting a one-pulse switching waveform to the rotating electrical machine 20 according to the electrical angle. The voltage amplitude is fixed to the maximum value, and the torque is feedback controlled by controlling the phase. ing. As described above, these three control modes are executed by the sine wave current control module 32, the overmodulation current control module 34, and the rectangular wave voltage phase control module 36, respectively.

Switching between the three modes of the sine wave current control mode, the overmodulation current control mode, and the rectangular wave voltage phase control mode is performed according to a modulation rate or a voltage command amplitude corresponding to the modulation rate. The modulation rate is the ratio of the signal amplitude to the output voltage of the inverter. In the case of the PWM method based on the comparison between the sine wave and the triangular wave, the modulation rate is {(3) ^1/2 } / 2 {(2) ^1/2 } = 0.61, and the rectangular wave is used as the signal amplitude. The modulation factor is {(6) ^1/2 } /π=0.78.

  Thus, in order to increase the output of the rotating electrical machine 20, the rectangular wave voltage phase control capable of increasing the modulation rate is more suitable. On the other hand, in the sine wave current control mode and the overmodulation current control mode, since a pseudo sine wave formed by the PWM technique is used, the response can be made faster than in the rectangular wave voltage phase control mode. Accordingly, it is preferable to use the sine wave current control mode in the low speed region, the overmodulation current control mode in the medium speed region, and the rectangular wave voltage phase control mode in the high speed region.

  FIG. 2 is a diagram for explaining how the control mode is selected according to the operating point of the rotating electrical machine. This figure shows the maximum torque characteristic line 50 with the rotation speed of the rotating electrical machine 20 on the horizontal axis and the torque on the vertical axis, and which control mode is used in the operation region indicated by the maximum torque characteristic line 50. FIG. As shown in this figure, a sine wave current control mode operation region 52 is set on the low speed side, a rectangular wave voltage phase control mode operation region 56 is set on the high speed side, and an overmodulation current control mode operation region 54 is set between them. ing.

  3 to 5 are diagrams showing states of the phase current waveform and the phase voltage waveform for the sine wave current control mode, the overmodulation current control mode, and the rectangular wave voltage phase control mode, respectively. In these figures, the horizontal axis represents time, and the vertical axis represents current or voltage. As shown in FIG. 3, in the sine wave current control mode, the phase voltage waveform is a set of fine pulses whose pulse width is modulated, and the phase current waveform is a pseudo sine wave formed by the PWM technique. Although the PWM technique is also used in the overmodulation current control mode, the phase voltage is overmodulated, so that the mode differs from the sine wave current control mode. In the rectangular wave voltage phase control mode, the interphase voltage has a rectangular wave waveform subjected to voltage phase control.

  Next, switching between these three control modes will be described. As shown in FIG. 2, the control mode is switched in accordance with the state of the operating point of the rotating electrical machine 20 given by the rotational speed and torque. As the speed and torque are gradually increased, the control mode is switched from the sine wave current control mode to the overmodulation current control mode, and from the overmodulation current control mode to the rectangular wave voltage phase control mode. In this case, the control mode can be switched according to the modulation rate as follows. That is, the sine wave current control mode when the modulation factor is 0.61 or less, the overmodulation current control mode when the modulation factor is between 0.61 and 0.78, and the rectangular wave voltage phase when the modulation factor is 0.78. The control mode is switched to use the control mode.

  The modulation rate can also be used when switching the control mode in the opposite direction. However, switching from the rectangular wave voltage phase control mode to the overmodulation current control mode is performed when the voltage command amplitude is constant in the rectangular wave voltage phase control mode. Therefore, it is performed by determining the switching timing based on the phase of the actual current with respect to the current command.

  The use of the sine wave current control mode, overmodulation current control mode, and rectangular wave voltage phase control mode has been described above. Next, vector control will be described using the dq plane. FIG. 6 shows a dq plane defined by the d axis and the q axis used for vector control of the rotating electrical machine 20. In the vector control used in the rotating field type three-phase synchronous motor, the direction of the magnetic flux formed by the magnetic poles of the rotor is taken as the d axis, and the axis orthogonal to the d axis is taken as the q axis. The dq plane is a plane configured with the d axis and the q axis as orthogonal coordinate axes.

Here, the d-axis inductance of the rotating electrical machine 20 is L _d , the q-axis inductance is L _q , the winding resistance is R, the electrical angular velocity is ω, the counter electromotive force constant is ψ, the d-axis current is I _d , and the q-axis current is If I _q , d-axis voltage is V _d , and q-axis voltage is V _q , the theoretical formula of the rotating electrical machine can be expressed as follows.

That is, the d-axis voltage V _d is given by V _d = R × I _d −ω × L _q × I _q . Further, the q-axis voltage V _q is given by V _q = R × I _q + ω × L _d × I _d + ωψ. Further, assuming that the number of poles of the rotating electrical machine 20 is p, the torque τ is given by τ = pψI _q + p (L _d −L _q ) I _d I _q .

Here, L _d and L _q are determined when the structure of the rotating electrical machine 20 is set, and both have positive values. Now, considering positive torque with I _q being positive, in the case of a salient pole type in which the rotor or stator of the rotating electrical machine 20 has salient poles, (L _d −L _q ) is positive, and I _d is The positive region is the operation region, but in the case of the non-salient pole type, since (L _d −L _q ) is negative, the negative region of I _d is the operation region. In this case, since the rotating electrical machine 20 is a non-salient pole type, the negative region of the d-axis current is the operating region, and FIG. 6 shows the state.

The absolute value I _a of the current vector defined by the d-axis current and the q-axis current is I _a = (I _d ² + I _q ² ) ^1/2 , and the current phase β is β = tan ⁻¹ (I _q / I _{If d} ), the equation of torque τ can be expressed by current phase β. That is, torque τ = pψI _a sin β + (1/2) × p (L _d −L _q ) I _a ² × sin 2β. This equation shows that the torque τ can be controlled by the current phase β. That is, the current phase indicates a phase between the d-axis current component and the q-axis current component in the current.

In this manner, the torque of the rotating electrical machine 20 can be controlled by controlling the current phase β. The current phase β giving the maximum torque can be obtained based on an equation in which the torque τ is differentiated by the current phase β and the value is set to zero. That is, β = cos ⁻¹ [[−ψ + {ψ ² −8 (L _d −L _q ) ² } ^1/2 ] / 4 (L _d −L _q ) I _a ] and current phase β at the maximum torque β Is required. Thus, a characteristic line that can operate the rotating electrical machine 20 with the maximum efficiency can be obtained by adding an appropriate correction to the relational expression obtained by the calculation as necessary.

  FIG. 6 shows a maximum efficiency characteristic line 62 obtained in this way. If the current command is executed on the maximum efficiency characteristic line 62, the rotating electrical machine 20 can be operated with the maximum efficiency. Therefore, the current command executed on the maximum efficiency characteristic line 62 is simply referred to as a current command.

  This maximum efficiency characteristic line 62 is a characteristic line obtained by connecting a current set of a d-axis current and a q-axis current that satisfy the current phase β at the maximum torque, and corresponds to these d-axis current and q-axis current. A characteristic line obtained by connecting a voltage set of the d-axis voltage and the q-axis voltage is shown as a voltage command characteristic line 66 in FIG.

  The maximum voltage circle 60 shown in FIG. 6 is a line indicating the maximum voltage supplied to the rotating electrical machine 20. In the rectangular wave voltage phase control mode, when the voltage amplitude is constant, Thus, the magnitude of torque output can be controlled by controlling the voltage phase. Therefore, the voltage command characteristic line 66 inside the maximum voltage circle 60 indicates a voltage set of the d-axis voltage and the q-axis voltage of the voltage command at the maximum efficiency operation in the sine wave current control mode and the overmodulation current control mode. Is.

  In this way, by using the dq plane, the maximum efficiency characteristic line 62 for executing the current command at the maximum efficiency operation in the sine wave current control mode and the overmodulation current control mode, and the corresponding voltage command are executed. A voltage command characteristic line 66 is shown. Further, it is indicated that the voltage command in the rectangular wave voltage phase control mode is executed on the maximum voltage circle 60.

  FIG. 6 shows a switching line 64 used when switching from the rectangular wave voltage phase control mode to the overmodulation current control mode. The switching line 64 is a characteristic line having a phase difference preset on the retard angle side of the maximum efficiency characteristic line 62 on the dq plane. The reason why the switching line 64 is retarded from the maximum efficiency characteristic line 62 is that if the control mode is switched on the advance side, the control causes chattering when the mode is switched and current disturbance may occur. Because it is known.

  The vector control has been described above including its normal control range. Next, torque feedback control in the rectangular wave voltage phase control mode will be described. In the rectangular wave voltage phase control mode, since a rectangular wave is used, periodic noise and harmonics are included in the d-axis current and the q-axis current. Therefore, a low-pass filter process is performed on the current value in the control process. This low-pass filter process is a so-called first-order lag process in which an actual signal is smoothed by a time constant. By this annealing process, the response may be delayed, and the d-axis current value may be out of the normal control range. Therefore, in the following, description will be made including the contents of control for preventing the d-axis current value from deviating from the normal control range by the annealing process.

  FIG. 7 is a control block diagram in the rectangular wave voltage phase control mode. Here, the rotating electrical machine (MG2) 20 described in FIG. 1, the MG2 inverter 17 in the power supply circuit 16, and the portion corresponding to the rectangular wave voltage phase control module 36 of the control unit 30 are shown.

As shown in this control block diagram, in the rectangular wave voltage phase control mode, the coordinate conversion unit 72 converts each phase current value of the rotating electrical machine 20 into a dq current value, passes through a first-order lag processing unit 74, and torque The estimation unit 76 calculates a torque estimated value T _qest from the dq current value, and performs torque feedback for feeding _back this to the torque command value T _qref .

Here, torque command value T _qref 70 is calculated based on a user's requested torque obtained from a vehicle accelerator or the like (not shown).

The coordinate conversion unit 72 acquires two current values and the rotation angle θ among the phase currents of the rotating electrical machine 20, and calculates the d-axis current value I _d and the q-axis current value I _q based on the respective phase current values. It has a function. In the example of FIG. 7, coordinate conversion is performed based on the V-phase current value I _v and the W-phase current value I _w acquired by appropriate current detection means, and the rotation angle θ of the rotating electrical machine 20 acquired by a resolver or the like. It has been broken.

The first-order lag processing unit 74 has a function of performing processing to suppress periodic noise and harmonics included in the d-axis current value I _d and the q-axis current value I _q that are actually measured values. Specifically, the real signal is smoothed using the time constant τ. As described above, the first-order lag processing is low-pass filter processing that appropriately sets a time constant and suppresses high-frequency noise and the like included in the actual signal. The d-axis current value I _dsm and the q-axis current value I _qsm that have been subjected to the first-order lag processing are used for subsequent control instead of the actual current values I _d and I _q .

The torque estimation unit 76 uses the calculated d-axis current value I _dsm and q-axis current value I _qsm that have been subjected to the first-order lag processing, and the torque equation τ = pψI _q + p (L _d according -L _q) I _d I _q, it has the function of calculating the torque, and outputs it as a torque estimate _T qest. Here, I _d in the above torque equation is replaced with I _dsm and I _q is replaced with I _qsm, and torque estimated value T _qest is calculated using the dq current value subjected to the first-order delay processing.

Subtractor 78 has a function of calculating the torque deviation ΔT by subtracting the torque estimation value T _Qest from the torque command value T _qref.

  Based on the relationship between the voltage phase φ and the torque T obtained in advance for the rotating electrical machine 20, the PI calculation unit 80 performs proportional-integral control under a predetermined gain to obtain a control deviation corresponding to the torque deviation ΔT. It has a function of calculating the voltage phase φ corresponding to the control deviation. In the rectangular wave voltage phase control mode, since the voltage amplitude is constant, torque control is executed by this voltage phase φ.

The rectangular wave generator 82 has a function of generating the phase voltage command values I _u , I _v , and I _w that are rectangular wave pulses based on the calculated voltage phase φ. Based on the phase voltage command value, it has a function of generating a control signal for each switching element constituting the inverter 17. Since the three-phase operation type inverter has six switching elements, FIG. 7 shows a state in which six control signals are supplied to the inverter 17. Thereby, a rectangular wave pulse of each phase according to the voltage phase φ is supplied to the rotating electrical machine 20.

  The above is the configuration of the main feedback loop when torque feedback is performed in the rectangular wave voltage phase control mode. Thus, in the main feedback loop, the estimated torque value calculated based on the dq current obtained by performing the first-order lag process on the actual current of the rotating electrical machine 20 is fed back to the torque command.

Here, when the torque command value changes suddenly, the torque deviation ΔT may become excessively large. In order to eliminate the ΔT, as a result, the d-axis current I _d calculated by the coordinate conversion unit 72 changes excessively, and in some cases, I _d becomes a positive value and deviates from the normal control range. Can happen. Therefore, to prevent this, another loop is provided as shown in FIG.

  That is, the torque deviation ΔT calculated by the subtractor 78 is supplied to the primary delay processing unit 74. Specifically, a time constant τ corresponding to the torque deviation ΔT at the timing of each control calculation cycle is obtained using a table 86 indicating the relationship of the time constant τ to the torque deviation ΔT, and the first order lag based on the time constant τ is obtained. The response characteristic 88 is applied to the first-order lag processing unit 74.

  Regarding the relationship between the torque deviation ΔT stored in the table 86 and the time constant, it is preferable that τ is large when the absolute value of the torque deviation ΔT is small and τ is small when the absolute value of ΔT is large. In this way, even if the torque deviation ΔT is excessively estimated due to a sudden change in the torque command value or the like, the estimated torque value can be quickly obtained using a value close to the actual current by reducing the time constant. Therefore, the overestimated state of ΔT can be quickly resolved.

  The specific relationship between the torque deviation ΔT and the time constant τ can be obtained in advance by experiments or calculations according to the specifications of the rotating electrical machine 20. FIG. 7 shows an example in which two large and small time constants are used with a certain threshold as an absolute value of the torque deviation ΔT. Of course, the relationship between ΔT and τ other than this example can be used according to the actual specifications of the rotating electrical machine 20 and the like.

  As the table 86, a look-up table showing a time constant τ that changes according to the torque deviation ΔT can be used. Instead of the table 86, other means for outputting the time constant τ by inputting the torque deviation ΔT may be used. For example, a map format may be used, or a mathematical formula may be used.

  In this way, by supplying the torque deviation ΔT to the primary delay processing unit 74, the excessive estimation of the deviation in the main feedback loop can be quickly eliminated, thereby causing the d-axis current value to change suddenly and deviate from the normal control range. Can be prevented.

  The rotating electrical machine control system according to the present invention can be applied to control of a rotating electrical machine that performs a smoothing process in a rectangular wave voltage phase control mode in which torque feedback is performed. In addition to a system including a rotating electrical machine mounted on a vehicle, the system can be used for a system including a rotating electrical machine used for driving other than the vehicle.

  DESCRIPTION OF SYMBOLS 10 Rotating electrical machine control system, 12 Engine, 14 Power storage device, 16 Power supply circuit, 17 Inverter, 18, 20 Rotating electrical machine, 22 Power distribution mechanism, 24 Transmission, 26 Tire, 30 Control unit, 32 Sine wave current control module, 34 Overmodulation current control module, 36 rectangular wave voltage phase control module, 40 current deviation judgment module, 42 switching control module, 50 maximum torque characteristic line, 52 sine wave current control mode operation region, 54 overmodulation current control mode operation region, 56 rectangular wave voltage phase control mode operation region, 60 maximum voltage circle, 62 maximum efficiency characteristic line, 64 switching line, 66 voltage command characteristic line, 72 coordinate conversion unit, 74 primary delay processing unit, 76 torque estimation unit, 78 subtraction , 80 PI operation unit, 82 rectangular wave generation unit, 84 signal generation unit, 86 Table, 88 response characteristics.

Claims (1)

A torque deviation calculating means that is a deviation between the torque command value and the torque estimated value;
Deviation control means that performs control to bring the calculated torque deviation closer to zero, generates a voltage phase command, and supplies the voltage phase command to the drive unit of the rotating electrical machine,
Dq current calculation means for calculating a d-axis current value and a q-axis current value based on each phase current value of the rotating electrical machine;
Smoothing processing means for subjecting the calculated d-axis current value and q-axis current value to first-order lag processing with a predetermined time constant and outputting the processed d-axis current value and the processed q-axis current value When,
A torque estimated value calculating means for calculating a torque estimated value based on the processed d-axis current value and the processed q-axis current value, and supplying the estimated torque value to the torque deviation calculating means;
With
The annealing process means
A rotating electrical machine control system that performs first-order lag processing using a time constant corresponding to a torque deviation.

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