JP2008131796A - Motor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor control device with improved of the deterioration in controllability due to the mutual interference of inverters that occurs, when executing distributed current control. <P>SOLUTION: In the motor control device has an inverter and a current sensor connected for each phase of a multi-phase AC motor, the device has each an integrated motor controller 11, that generates the current command value of each phase from a torque command value and a rotor angle, or generates a current command value for each phase and an induced-voltage estimated value for each phase from the torque command value, the current command value for each phase, the rotor angle, and rotor angle velocity. The device also has each a distribution driver 12 that subjects the voltage of own inverter to current-feedback control, on the basis of at least one among the current command value of all phases, the rotor angle, and the rotor angular velocity, or subjects the voltage of own inverter to current-feedback control, on the basis of the phase current command value of the corresponding phase and the phase induced voltage estimated value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor control device, and more particularly to a motor control device that controls driving of a multiphase AC motor.

Conventionally, a motor control device that controls driving of a multiphase AC motor is known.
In general, when a three-phase AC motor is driven by N (N ≧ 3) inverters, for example, as described in “Control Device for Multiple Winding Induction Motor” (see Patent Document 1), N-phase currents are collectively collected. Thus, it is necessary to generate a pulse width modulation (PWM) gate signal for each inverter. For this reason, it has been difficult to disperse and arrange the batch processing portion called “PWM control unit” beside the N inverters. Since the PWM gate signal includes a high frequency band, it is vulnerable to noise. In particular, when noise is superimposed on the PWM gate signal, a fatal failure such as a DC short circuit is often induced.

On the other hand, in the “PWM inverter device” (see Patent Document 2), each inverter has a current sensor and a current control loop, and each inverter receives each current command from an integrated motor controller (integrated MC). Only. For this reason, it is possible to prevent noise from being superimposed on the PWM gate signal. In addition, the control part of the inverter is distributed, and the N inverter modules function independently of each other, so that it can be manufactured with a uniform design and the design / manufacturing cost can be reduced, and the PWM carrier signal can be independently set. Holding it will also help reduce motor inverter noise.
Japanese Patent Laid-Open No. 10-42589 Japanese Patent Laid-Open No. 10-313591

However, in the conventional “PWM inverter device”, the current of the own coil is disturbed by the induced electromotive force of the motor generated because the own coil is linked to the magnetic flux generated by the inverter current of the other phase. That is, the controllability is reduced due to the mutual interference between the inverters.
FIG. 8 is a control configuration diagram illustrating conventional distributed current control. As shown in FIG. 8, the current actual value Iact [A] fed back from the motor coil is subtracted from the current command value Iref [A], and the obtained current error Ierr [A] is input to the PI controller. To do. The PI controller to which the current error Ierr [A] is input outputs the current feedback control operation voltage Vfb [V], and the current feedback control operation voltage Vfb [V] is converted into an ON / OFF signal (triangular wave comparison PWM or the like). The PWM voltage is input to the motor coil.

That is, the control voltage Vfb [V] is applied to the motor coil to control the coil current, but the change in the linkage flux to the motor coil due to other coil current changes, and the induced electromotive force generated thereby The disturbance voltage changes the coil current.
Furthermore, when this control method is applied to IPM (embedded permanent magnet motor), SRM (switched reluctance motor), SynRM (synchronous reluctance motor), etc., the inductance of the coil changes depending on the rotor angle. It was inevitable that the control gain could not be increased and the response deteriorated.

FIG. 9 is an explanatory diagram illustrating the relationship between the change in the rotor angle in the SRM and each phase coil inductance in a graph. As shown in FIG. 9, the instantaneous inductance of each phase coil changes as a function of the rotor angle with respect to the stator. When the rotor pole and the stator teeth are in a non-opposing position, the inductance is small and the rotor pole and the stator teeth are opposed to each other. When in position, the inductance is large.
An object of the present invention is to provide a motor control device in which a decrease in controllability caused by mutual interference between inverters, which occurs when performing distributed current control.

  In order to achieve the above object, a motor control device according to the present invention is a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor. An integrated motor controller that generates a value, an all-phase current command value, and a distributed driver that performs current feedback control of the inverter voltage based on at least one of a rotor angle and a rotor angular velocity.

  According to this invention, the motor control device in which the inverter and the current sensor are connected for each phase of the multiphase AC motor, the integrated motor controller generates each phase current command value from the torque command value and the rotor angle, The distributed driver performs current feedback control of the inverter voltage based on the all-phase current command value and at least one of the rotor angle and the rotor angular velocity. For this reason, it is possible to improve a decrease in controllability caused by mutual interference between inverters, which occurs when performing distributed current control.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram schematically illustrating the configuration of a motor control device according to an embodiment of the present invention. As shown in FIG. 1, the motor control apparatus 10 has an integrated motor controller (MC) 11 and a distributed driver 12, and drives the motor 13 via the distributed driver 12 to which a control signal from the integrated MC 11 is input. To control. The distributed driver 12 is provided with a number (1 to n) corresponding to the number of windings 13a of the motor 13 to be controlled.
The integrated MC 11 performs processing of receiving a torque command, detecting a rotor angle (rotor angle sensing), and calculating each phase current command. That is, the integrated MC 11 generates each phase current command I (1 to n) ref (t) by inputting the torque command Tref (t) and the rotor angle θact (t), and generates each phase current command I (1 N) ref (t) and the rotor angle θact (t) are output to each distributed driver 12.

  Each distributed driver 12 includes a current sensor 14 and an intelligent power module 15, and receives a current command, detects a current (current sensing), calculates an inductance, calculates an induced electromotive force (counterelectromotive force (cEMF)), Each process of a current feedback (FB) control loop and a gate drive is performed. The current sensor 14 and the intelligent power module 15 may be provided separately from the distributed driver 12 instead of being provided integrally with the distributed driver 12.

In other words, each distributed driver 12 has a built-in gain correction function based on inductance calculation and an FF (Feed Forward) compensation function based on cEMF calculation, and each phase current command I (1-n) ref (t In other words, the inverter voltage is subjected to current feedback control based on all-phase current command and at least one of the rotor angle and the rotor angular velocity. Only the low-frequency analog signal is used between the integrated MC 11 and each distributed driver 12.
Therefore, the motor control device 10 to which the inverter and the current sensor are connected for each phase of the multiphase AC motor is configured so that the respective distributed drivers 12 have the windings 13a of the distributed drivers based on the rotor angle and the current command of all phases. Since the induced voltage induced in can be calculated and corrected, the current control responsiveness can be ensured without increasing the current control deviation.

One of the motors 13 includes a rotor angle sensor 16 that detects the rotor angle.
FIG. 2 is a block diagram schematically illustrating another configuration of the motor control device of FIG. As shown in FIG. 2, the motor control device 20 includes an integrated MC 21 and each distributed driver 22 instead of the integrated MC 11 and each distributed driver 12.
The integrated MC 21 performs processing of torque command reception, rotor angle detection (rotor angle sensing), calculation of each phase current command, and cEMF calculation. Each distributed driver 22 receives current command and detects current. (Current sensing), current FB (FeedBack) control loop, cEMF correction, and gate drive processing are performed. Other configurations and operations of the integrated MC 21 and each distributed driver 22 are the same as those of the integrated MC 11 and each distributed driver 12.

That is, the integrated MC 21 calculates the cEMF, and each distributed driver 22 corrects the cEMF without calculating the inductance and the cEMF, and the integrated MC 21 calculates the torque command Tref (t) and the rotor angle. By inputting θact (t), current commands I (1 to n) ref (t) and cEMF (1 to n) (t) for each phase are generated and output to the dispersion driver 22 for each phase.
Therefore, each dispersion driver 22 receives the current command value and the induced voltage estimated value of the phase, and has a built-in FF compensation function based on the induced voltage calculation. Since the induced voltage induced by the magnetic flux generated in the winding of the distributed driver can be corrected, the current control response can be ensured without increasing the current control deviation, and the induced voltage must be calculated by the distributed driver. Therefore, the distributed driver can be configured easily and the cost can be reduced.

FIG. 3 is a block diagram schematically illustrating still another configuration of the motor control device of FIG. As shown in FIG. 3, the motor control device 25 has each distributed driver 26 instead of each distributed driver 12.
Each distributed driver 26 performs processing of receiving a current command, detecting current (current sensing), calculating an inductance, a current feedback (FB) control loop, and a gate drive. Other configurations and operations of the distributed drivers 26 are the same as those of the distributed drivers 12.
That is, the integrated MC 11 generates a current command I (1 to n) ref (t) for each phase based on the input of the torque command Tref (t) and the rotor angle θact (t), and supplies the current to the distributed driver 26 for each phase. Each distributed driver 26 does not calculate cEMF, but calculates angular velocity (differentiation) and inductance. The number of signals between the integrated MC 11 and each distributed driver 26 is doubled, and only low frequency analog signals are used.

Therefore, by providing an inductance calculation function on the distributed driver 26 side, it is possible to improve the response of the current FB control by sending only the rotor angle signal to the distributed driver. Therefore, in each distributed driver, the instantaneous inductance of the winding of the distributed driver can be calculated, so that the feedback gain of current control can be adjusted and the gain can be increased without destabilization. The current control response can be secured without increasing the control deviation.
FIG. 4 is a block diagram schematically illustrating still another configuration of the motor control device of FIG. As illustrated in FIG. 4, the motor control device 30 includes an integrated MC 31 and each distributed driver 32 instead of the integrated MC 11 and each distributed driver 12.

  The integrated MC 31 performs each process of receiving a torque command, detecting a rotor angle (rotor angle sensing), calculating each phase current command, and calculating each phase's inductance and cEMF (each phase L / cEMF calculation). The distributed driver 32 performs processes of receiving a current command, detecting a current (current sensing), calculating a variable gain, a current feedback (FB) control loop, and a gate drive. Other configurations and operations of the integrated MC 31 and each distributed driver 32 are the same as those of the integrated MC 11 and each distributed driver 12.

  That is, the integrated MC 31 calculates the inductance and cEMF of each phase by inputting the torque command Tref (t) and the rotor angle θact (t), and calculates the current command I (1 to n) ref (t) of each phase. It is generated and outputted to the dispersion driver 32 of each phase, and each dispersion driver 32 performs only gain adjustment and FF compensation without calculating the inductance and cEMF of each phase. The number of signals between the integrated MC 31 and each distributed driver 32 is three times, and only low-frequency analog signals are used.

Accordingly, by providing the integrated MC 31 side with the function of calculating the inductance value to be gain-corrected and the voltage value to be FF-compensated, it is possible to have the function of gain correction and FF compensation while minimizing the function of the distributed driver 32. . Therefore, in each distributed driver 32, the feedback gain of current control can be adjusted by the instantaneous inductance of the winding 13a of the driver, and the gain can be increased without destabilization. The current control response can be ensured without increasing.
Next, a distributed current control configuration according to the present invention will be described.

FIG. 5 is a control configuration diagram for explaining the distributed current control according to the present invention. As shown in FIG. 5, the current actual value Iact [A] fed back from the motor coil is subtracted from the current command value Iref [A], and the obtained current error Ierr [A] is input to the PI controller. To do. The current feedback control operation voltage Vfb1 [V] output from the PI controller to which the current error Ierr [A] is input is subjected to addition processing of the induced voltage compensation Vff [V] depending on the rotor angle and the rotor rotational speed, The current control operation voltage Vfb2 [V] is obtained. After the current control operation voltage Vfb2 [V] is turned into an ON / OFF signal (triangular wave comparison PWM or the like), an induced electromotive force disturbance Vex from another coil is added and input to the motor coil as a PWM voltage.
In this way, the FF compensation is performed for the induced electromotive force disturbance by making the current control gain of each inverter proportional to the instantaneous inductance of the own coil.

That is, in order to cancel the induced electromotive force disturbance, the induced voltage compensation Vff is added to the current FB control operation voltage Vfb1, and the current FB control operation voltage Vfb2 is applied to the motor coil. The induced voltage compensation Vff can be obtained from the command value or measured value of the other coil current and its change rate, the rotor angle and its change rate. For example, with respect to the coil N, assuming that other coil currents are I (1) to I (n-1) and the rotor angle is θ, the interlinkage magnetic flux PHI (n) of the coil is obtained as follows.
PHI (n)
= K1 (θ) I (1) + k2 (θ) I (2) +... Kn−1 (θ) I (n−1)
However, k1 to kn-1 are coupling coefficients between the coils and the magnetic flux of the coil N and depend on the rotor angle θ, and are obtained by numerical calculation such as a virtual magnetic path method or a finite element method. I can leave.

From this equation, the induced electromotive force disturbance Vex is
Vex = dPHI (n) / dt
= (Dk1 / Dt) I (1) + k1 (DI (1) / Dt) + (Dk2 / Dt) I (2) + k2 (DI (2) / Dt) + ... + (Dkn-1 / Dt) I (n-1) + kn-1 (DI (n-1) / Dt)
= Dk1 / Dθ × dθ / dt × I (1) + k1DI (1) / Dt + Dk2 / Dθ × dθ / dt × I (2) + k2DI (2) / Dt +... + Dkn−1 / Dθ × dθ / dt × I (N-1) + kn-1DI (n-1) / Dt
= (I (1) Dk1 / Dθ + I (2) Dk2 / Dθ +... + I (n−1) Dkn−1 / Dθ) × dθ / dt + (k1DI (1) / Dt + k2DI (2) / Dt +... + Kn -1DI (n-1) / Dt)

Can be obtained as follows. Therefore, the induced voltage compensation Vff is
Vff = -Vex
Can be calculated.
The above algorithm is calculated using the following variables.
-Coupling coefficient between each coil and the magnetic flux of the coil N-Angle change rate of coupling coefficient between each coil and the magnetic flux of the coil N-Rotor angle-Rotor angle time change rate (rotor speed)
・ Current of each coil ・ Current time change rate of each coil

The "coupling coefficient angle change rate-rotor angle" table can be calculated from the "coupling coefficient-rotor angle" table. Similarly, the rotor angle time change rate and the current time change rate are also respectively calculated as the rotor angle It can be easily obtained from the current signal. For this reason, the amount of actual calculations and necessary resources (CPU and memory) is small.
Thus, the current control gain of each inverter is changed, for example, proportional, based on the instantaneous inductance of its own coil. Therefore, the control can be performed based on the response characteristic of the current control load, and the gain can be changed so that the change in the response characteristic of the current control load can be canceled, so that the current control response is improved.

FIG. 6 is a control configuration diagram illustrating another distributed current control according to the present invention. FIG. 7 is an explanatory diagram illustrating the relationship between the change in the rotor angle and each phase coil inductance in a graph. As shown in FIG. 6, the current control operation voltage Vfb [V] is obtained by multiplying the current FB control voltage operation amount output from the PI controller by a gain correction coefficient K. Other configurations and operations are the same as those of the distributed current control shown in FIG.
That is, since the instantaneous inductance of the motor winding changes depending on the rotor angle (see FIG. 3), feedback gain correction is performed to change the current control gain of each inverter based on the instantaneous inductance of its own coil. Since the instantaneous inductance of each phase can be mapped as a function of the rotor angle, the value is used as the current control gain correction coefficient K.

FIG. 7 shows the standardization when the current FB controller is designed based on the inductance of the rotor stator ratio facing position. The correction of the non-facing position is 1, and the current response delay due to the increase of the inductance at the facing position. Is multiplied by a correction coefficient larger than 1.
As a result, for example, the disturbance value for the current control can be directly corrected based on the disturbance value for the current control, so that the response of the current control is improved, and the deterioration or instability of the response is improved. can do.
Further, in the motor control device having the above-described configuration, even if operation is performed by one pulse control of each distributed driver from the integrated MC using a back electromotive force (induced electromotive force: cEMF) or a signal (line) of an FF compensation signal. Good.

In other words, it may be used in the “operation mode in which the current FB control function of the distributed driver is stopped and the on / off signal is directly applied from the integrated MC”, such as one-pulse control. That is, normally, it is necessary to command the integrated MC to start, operate, and stop the current FB control function of the distributed driver, and to respond to the integrated MC with the control state of the distributed driver, and a control signal line for this is required. It was. However, in the case of a system having an FF compensation signal from the integrated MC to the dispersion driver, it is not necessary to suspend the current FB control function of the dispersion driver. By making this FF compensation signal larger than a predetermined voltage (power supply voltage), one pulse It can be in a controlled state.
This makes it possible to reduce the stop signal and the one-pulse ON / OFF timing signal at the time of stop in the current control between the integrated MC and the distributed driver, which should be normal, so that the number of signals and the number of wirings can be reduced.

Further, in the motor control apparatus having the above-described configuration, the operation / pause of each distributed driver may be controlled from the integrated MC using an instantaneous inductance or a variable gain signal (line).
In other words, when starting / running / stopping each distributed driver, a control signal line is usually required. However, in the case of a system having a gain correction signal from the integrated MC to the distributed driver, the integrated MC There is no need to generate a start / run / stop signal, and a gain correction signal can be used to stop if the gain is set to 0, and to operate if the gain is set to a predetermined value or more.
This makes it possible to reduce the current control start / stop signals between the integrated MC and the distributed driver, which should normally be, so that the number of signals and the number of wirings can be reduced.

As described above, in a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor, an integrated motor controller that generates each phase current command value from a torque command value and a rotor angle, A distributed driver that performs current feedback control of the inverter voltage based on at least one of a current command value and a rotor angle and a rotor angular velocity is characterized.
Further, in a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor, each phase current command value and each phase are calculated from the torque command value, each phase current command value, the rotor angle and the rotor angular velocity. An integrated motor controller that generates an induced voltage estimated value and a distributed driver that performs current feedback control of the inverter voltage based on the phase current command value and the phase induced voltage estimated value of the phase.

The distributed driver corrects the voltage command value of each inverter based on the instantaneous induced voltage calculation value of its own coil.
The induced voltage value is subtracted from the voltage command value.
In addition, in a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor, an integrated motor controller that generates each phase current command value from a torque command value and a rotor angle, and a phase current of the phase And a distributed driver that performs current feedback control of the inverter voltage based on the command value and the rotor angular position.
An integrated motor that generates an instantaneous inductance of each phase current command value and each phase winding from a torque command value and a rotor angle in a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor It has a controller and a distributed driver that performs current feedback control of the inverter voltage based on the phase current command value and instantaneous inductance of the phase.

The distributed driver is characterized in that the current control gain of each inverter is changed based on the instantaneous inductance of its own coil.
Further, the current control gain of each inverter is proportional to the instantaneous inductance of its own coil.
Further, the one-pulse operation of each of the distributed drivers is controlled from the integrated motor controller using a back electromotive force or an FF compensation signal.
In addition, the operation / pause of each distributed driver is controlled from the integrated motor controller using a signal with a variable instantaneous inductance or gain.

1 is a block diagram schematically illustrating a configuration of a motor control device according to an embodiment of the present invention. FIG. 3 is a block diagram schematically illustrating another configuration of the motor control device of FIG. 1. FIG. 7 is a block explanatory diagram schematically illustrating still another configuration of the motor control device of FIG. 1. FIG. 7 is a block explanatory diagram schematically illustrating still another configuration of the motor control device of FIG. 1. It is a control block diagram explaining the distributed current control concerning this invention. It is a control block diagram explaining the other distributed current control which concerns on this invention. It is explanatory drawing which shows the relationship between the change of a rotor angle | corner, and each phase coil inductance with a graph. It is a control block diagram explaining the conventional distributed current control. It is explanatory drawing which shows the relationship of the change of the rotor angle in SRM, and each phase coil inductance with a graph.

Explanation of symbols

10, 20, 25, 30 Motor controller 11, 21, 31 Integrated MC
12, 22, 26, 32 Distributed driver 13 Motor 13a Winding 14 Current sensor 15 Intelligent power module 16 Rotor angle sensor

Claims (10)

In a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor,
An integrated motor controller for generating each phase current command value from the torque command value and the rotor angle;
A motor control device comprising: a distributed driver that performs current feedback control of a self inverter voltage based on an all-phase current command value and at least one of a rotor angle and a rotor angular velocity. In a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor,
An integrated motor controller that generates each phase current command value and each phase induced voltage estimated value from the torque command value, each phase current command value, rotor angle and rotor angular velocity;
A motor control device comprising: a distributed driver that performs current feedback control of the inverter voltage based on a phase current command value and a phase induced voltage estimation value of the phase.   The motor controller according to claim 1, wherein the distributed driver corrects the voltage command value of each inverter based on the instantaneous induced voltage calculation value of its own coil.   The motor control device according to claim 3, wherein an induced voltage value is subtracted from the voltage command value. In a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor,
An integrated motor controller for generating each phase current command value from the torque command value and the rotor angle;
A motor control device comprising: a distributed driver that performs current feedback control of the inverter voltage based on a phase current command value and a rotor angular position of the phase. In a motor control device in which an inverter and a current sensor are connected for each phase of a multiphase AC motor,
An integrated motor controller that generates each phase current command value and instantaneous inductance of each phase winding from the torque command value and rotor angle;
And a distributed driver that performs current feedback control of the inverter voltage based on the phase current command value and instantaneous inductance of the phase.   The motor control device according to claim 5, wherein the distributed driver changes a current control gain of each inverter based on an instantaneous inductance of the own coil.   8. The motor control device according to claim 7, wherein the current control gain of each inverter is proportional to the instantaneous inductance of the own coil.   8. The motor control device according to claim 2, wherein one pulse operation of each of the distributed drivers is controlled from the integrated motor controller using a back electromotive force or an FF compensation signal. 9.   9. The motor control device according to claim 4, wherein operation / pause of each of the distributed drivers is controlled from the integrated motor controller using an instantaneous inductance or variable gain signal.

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