JP2011239563A - Motor control apparatus and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a magnetic pole position sensor signal automatically by using an inverter which controls a motor.SOLUTION: A magnetic pole estimator 2 supplies a motor 1 having electrical saliency in its rotor with a high-frequency voltage or current for detecting a magnetic pole position of the rotor via an inverter 6, and measures a response current or voltage from the motor 1 to estimate a rotor magnetic pole position of the motor 1. A magnetic pole position sensor 3 detects the magnetic pole position of the motor 1, and a magnetic pole position detector 4 calculates the magnetic pole position from the output signal of the magnetic pole position sensor 3. An initial position corrector 5 calculates a difference between a magnetic pole position estimation value from the magnetic pole estimator 2 and the magnetic pole position calculated by the magnetic pole position detector 4, and supplies the difference as a correction value. The inverter 6 uses a correction value supplied from the initial position corrector 5 to correct a magnetic pole position signal obtained from the magnetic pole position detector 4, thereby controlling drive of the motor 1 based on the corrected magnetic pole position.

Description

  The present invention relates to a control device that controls rotation of an electric motor and performs correction and failure diagnosis of a magnetic pole position sensor mounted on the electric motor.

  The magnetic pole position sensor of the electric motor is attached to the electric motor as accurately as possible so that an attachment angle error does not occur when the electric motor is assembled. However, in reality, the mounting angle error cannot be made zero, and the initial position shift occurs due to variations in the mounting angle of the magnetic pole position sensor, making it difficult to operate the motor with high accuracy and high efficiency by the control device. Yes.

  In order to realize high-precision and high-efficiency operation of the electric motor, it is necessary to correct the initial position of the magnetic pole position sensor. The correction means includes, for example, a magnetic pole position sensor, an electric motor attached to the rotor, a device that rotates the electric motor from the outside, a device that detects an induced voltage of the electric motor, and a correction value writing device to the inverter. Consists of. The rotor is rotated by a device that rotates the motor from the outside, the induced voltage is measured by a device that detects the induced voltage of the motor, and the magnetic pole position information, the magnetic pole position sensor, and the magnetic pole position detection estimated from the phase of the induced voltage The initial position deviation of the magnetic pole position sensor is corrected by detecting the initial position deviation from the difference in the magnetic pole position information of the detector and storing the correction value in the inverter by the correction value writing device to the inverter.

  As described above, the magnetic pole position sensor has an initial position deviation at the time of installation, which makes it difficult to control the motor with high accuracy and increases the efficiency due to the phase error of the voltage applied to the motor or the supplied current. Incurs a decline. The magnetic pole position sensor correction method requires a dedicated device as described above, and further increases the number of work steps. Then, the motor and the inverter must be managed on a one-to-one basis, and when the motor or the inverter is replaced, the above correction must be performed again.

  Accordingly, an object of the present invention is to provide a method of automatically correcting a magnetic pole position sensor signal using an inverter that drives an electric motor.

  An electric motor control device according to an embodiment of the present invention supplies a high-frequency voltage or current for detecting the magnetic pole position of the rotor to an electric motor having electrical saliency on the rotor, and the response current or voltage of the electric motor Magnetic pole position estimation means for estimating the rotor magnetic pole position of the electric motor, a magnetic pole position sensor for detecting the magnetic pole position of the electric motor, and magnetic pole position detection for obtaining the magnetic pole position from the output signal of the magnetic pole position sensor An initial position correcting means for obtaining a difference between the magnetic pole position estimated value from the magnetic pole position estimating means and the magnetic pole position obtained by the magnetic pole position detecting means, and providing the difference as a correction value; The correction value provided by the means is used to correct the magnetic pole position signal obtained from the magnetic pole position detection means, and the motor is driven and controlled based on the corrected magnetic pole position. ; And a converter.

  Since the electric motor has electric saliency in the rotor, a change occurs in the magnetic pole resistance of the magnetic pole circuit including the stator winding and the rotor during the rotation of the electric motor. This means that the inductance value of the stator winding varies depending on the magnetic pole position of the rotor of the electric motor. In the present invention, for example, at the time of starting up the apparatus, a high-frequency signal for detecting the rotor position is applied to the motor using the inductance characteristics of the motor having electrical saliency in the rotor, and the rotor is detected from the detected response current. Estimate the position. Based on the estimated rotor position, the magnetic pole position detected by using the position sensor 3 is corrected. The control unit controls the inverter based on the corrected magnetic pole position.

  Thus, the motor can be driven with high accuracy and high efficiency without requiring a device for rotating the motor from the outside, a device for measuring the induced voltage, and a correction value writing device for the inverter.

  It is possible to automatically correct the magnetic pole position sensor signal using an inverter that drives the electric motor.

The block diagram which shows the structure of the electric motor control apparatus in embodiment of this invention. The flowchart which shows the 1st Example of this invention. The flowchart which shows the 2nd Example of this invention. The flowchart which shows the 3rd Example of this invention. The flowchart which shows the 4th Example of this invention. The block diagram which shows the modification of the electric motor control apparatus of FIG.

  Embodiments of an electric motor control device according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing the configuration of an electric motor control apparatus to which the present invention is applied.

  The inverter 6 includes an inverter control unit 6a. The control unit 6a generates a gate signal of the inverter 6 based on an input signal such as a control command (acceleration / deceleration command or speed command) and controls the inverter 6. Under the control of the control unit 6a, the inverter 6 converts the input DC voltage of the power source 9 into a three-phase voltage having a desired magnitude and frequency, and drives the motor 1.

  The electric motor 1 is an electric motor having electrical saliency on a rotor, and is a permanent magnet synchronous motor using, for example, a permanent magnet as a rotor. The electric motor having electric saliency on the rotor means an electric motor having different inductance depending on the rotational position of the rotor when a predetermined voltage vector is applied.

  A magnetic pole position sensor 3 is attached to the electric motor 1. The magnetic pole position detector 4 generates a magnetic pole position signal based on the output signal of the magnetic pole position sensor 3. As the magnetic pole position sensor 3, a sensor such as a Hall sensor, a resolver, or an encoding method is used. The magnetic pole position signal output from the magnetic pole position detector 4 includes, for example, an angle pulse output at every predetermined rotation angle of the rotor and a magnetic pole position pulse indicating the magnetic pole position of the rotor.

  The magnetic pole position estimator 2 estimates the magnetic pole position (rotor angular position). This magnetic pole position can be estimated by superimposing a high-frequency component for magnetic pole position detection on the applied voltage or supply current from the inverter to the motor, and detecting and analyzing the response current or voltage of the motor. The magnetic pole position estimator 2 supplies high-frequency voltage or current to the electric motor 1 via the inverter 6, and the stator winding inductance value according to the electric saliency of the rotor of the electric motor 1, that is, the magnetic pole position of the rotor. Is measured from the current or voltage to estimate the magnetic pole position.

  The initial position corrector 5 provides the inverter 6 with the difference between the position estimated value of the magnetic pole position estimator 2 and the magnetic pole position from the magnetic pole position detector 4 as a correction value of the initial position deviation of the magnetic pole position sensor 3. The control unit 6a of the inverter 6 stores the correction value in the correction value storage unit 8 and corrects the magnetic pole position signal from the magnetic pole position detector 4 using the correction value. The controller 6a determines the phase of the alternating current supplied to the motor 1 based on the corrected magnetic pole position signal, and realizes high-precision and high-efficiency operation of the motor 1.

  FIG. 2 is a flowchart showing the operation of the first embodiment of the motor control apparatus to which the present invention is applied. This operation is performed before the device is shipped from the factory, for example.

  First, when the inverter is activated, that is, when the main switch of the apparatus is turned on and power is supplied to the inverter 6, the control unit 6a determines whether there is a request for initial position setting of the magnetic pole position sensor 3 (step S101). When there is an initial position setting request for the magnetic pole position sensor 3, the magnetic pole position estimator 2 applies a high frequency voltage or current for position measurement from the inverter 6 to the electric motor 1 (step S102). The magnetic pole position estimator 2 detects the response current and voltage of the motor at this time, estimates the magnetic pole position from the relationship between the voltage and current and the electric saliency of the rotor, and calculates the magnetic pole position estimated value as the magnetic pole position. Is output to the initial position corrector 5 as a true value (step S103).

  The initial position corrector 5 calculates a difference (initial position deviation) between the magnetic pole position estimation value and the magnetic pole position signal supplied from the magnetic pole position detector 4, and provides this difference to the inverter 6 as a correction value (step). S104). The control unit 6a of the inverter 6 stores this correction value in the correction value storage unit 8 (step S105) and completes the initial setting (step S106).

  In step S101, when there is no request for initial position setting of the magnetic pole position sensor, or when the initial position setting has been completed, the control unit 6a reads out the magnetic pole position correction value from the correction value storage unit 8 (step S107). The magnetic pole position provided from the magnetic pole position detector 4 is corrected using the value (step S108). The control unit 6a controls the electric motor 1 via the inverter 6 based on the corrected magnetic pole position. As a result, the motor 1 can be operated with high accuracy and high efficiency.

  FIG. 3 is a flowchart showing the operation of the second embodiment of the motor control apparatus to which the present invention is applied. In the second embodiment, the magnetic pole position is estimated a plurality of times, and the average value is adopted as the magnetic pole position estimated value.

  As in the first embodiment, when there is a request for setting the initial position of the magnetic pole position sensor 3, the magnetic pole position estimator 2 applies a high-frequency voltage or current for position measurement to the motor via an inverter to estimate the magnetic pole position. (S201 to 203). Here, the magnetic pole position estimator 2 performs magnetic pole position estimation a plurality of times. That is, the magnetic pole position estimator 2 determines whether or not the current estimated number n is equal to or greater than the set number N (204). Thus, in this embodiment, the magnetic pole position is estimated a plurality of times by applying a high frequency voltage or current for position measurement for a preset number of times N.

  When the magnetic pole position estimation is performed N times, the magnetic pole position estimator 2 averages the N magnetic pole position estimation values (S205). By averaging the estimated values, the influence of the magnetic pole estimation error is reduced. Next, similarly to the first embodiment, the magnetic pole position corrector 5 obtains the initial position deviation of the magnetic pole position sensor 3 and provides it to the inverter 6 as a correction value. The control unit 6a stores the correction value, and the initial setting is Completion (S206-S208).

  When there is no request for initial position setting of the magnetic pole position sensor, or when the initial position setting has been completed, the control unit 6a uses the magnetic pole position detector based on the stored magnetic pole position correction value as in the first embodiment. The motor 1 is controlled via the inverter 6 based on the corrected magnetic pole position signal. As a result, the motor 1 can be operated with high accuracy and high efficiency.

  FIG. 4 is a flowchart showing the operation of the third embodiment of the motor control apparatus to which the present invention is applied. In addition to the second embodiment, the third embodiment considers the variation of the magnetic pole position estimated value, excludes the estimated value that deviates from the preset variation range, and averages the remaining estimated values to obtain the magnetic pole position estimated value. Ask.

  Similar to the second embodiment, the magnetic pole position estimator 2 estimates the magnetic pole position N times according to the initial position setting request of the magnetic pole position sensor 3 (S201 to S204). Here, the magnetic pole position estimator 2 excludes estimated values that deviate from the preset variation range (S301), and averages the remaining estimated values (S205). When estimating the magnetic pole position of an electric motor, noise that cannot be ignored may be mixed in the voltage value or current value detected in response to the high-frequency component for position measurement. In such a case, the magnetic pole position estimation value includes a large error. Therefore, the influence of noise is reduced by excluding estimated values that deviate from the preset variation range. The subsequent processing is the same as in the second embodiment. According to the third embodiment, it is possible to perform more accurate control and high-efficiency driving of the electric motor.

  FIG. 5 is a flowchart showing the operation of the fourth embodiment of the motor control apparatus to which the present invention is applied. In the fourth embodiment, the magnetic pole position is estimated during normal operation of the electric motor, the difference from the detected value of the magnetic pole position sensor is obtained, and if the difference is larger than a predetermined value, it is determined that there is a failure.

  Similar to the first embodiment, the initial position of the magnetic pole position sensor is set (S101 to S106). When the initial position setting is completed or when there is no request for initial position setting, the control unit 5a reads the stored initial position correction value (S107), corrects the magnetic pole position signal (S108), and starts motor control. (S109).

  During the motor control, the magnetic pole position estimator 2 applies a high frequency voltage or current to the electric motor 1 via the inverter 6 to estimate the magnetic pole position (S401). The initial position corrector 5 calculates the difference between the estimated value and the magnetic pole position signal from the magnetic pole position detector (S402), and when the difference is equal to or larger than a preset value, the magnetic pole position sensor 3 or the magnetic pole position detector. 4 is determined to be a failure (S405). In response to this determination, the control unit 6a stops the operation of the inverter 6 and notifies the user that a failure has occurred. This failure determination process (steps S401 to S404) is performed, for example, every time the user turns on the main switch of the apparatus after the apparatus has passed to the user.

  As described above, in the fourth embodiment, when a failure occurs in the magnetic pole position sensor 3 or the magnetic pole position detector 4, the failure can be detected immediately, and high-precision control and high-efficiency driving of the electric motor are ensured. In addition, the safety of the device is improved.

  Next, a modified example of the configuration of the motor control device shown in FIG. 1 will be described as a fifth embodiment.

  FIG. 6 is a block diagram showing a modified example of the configuration of the motor control device.

  The initial position corrector 5 has a magnetic pole position storage unit 8. The initial position corrector 5 stores the difference between the magnetic pole position estimated value provided from the magnetic pole position estimator 2 and the magnetic pole position detected value from the magnetic pole position detector 4 as a correction value for the initial position deviation of the magnetic pole position sensor 3. Stored in section 8. Further, the initial position corrector 5 corrects the magnetic pole position signal from the magnetic pole position detector 4 using the stored correction value, and provides the corrected magnetic pole position signal to the inverter 6. The control unit 6a of the inverter 6 controls the inverter 6 based on the corrected magnetic pole position signal.

  According to the present embodiment, the control unit 6a of the inverter 6 does not need to control the motor while correcting the magnetic pole position signal as in the above embodiment, so that the processing load of the control unit 6a compared to the embodiment of FIG. The amount is reduced.

  As described above, according to the present invention, it is possible to automatically correct the magnetic pole position sensor using the inverter that drives the electric motor. The above description is an embodiment of the present invention, and does not limit the apparatus and method of the present invention. Various modifications can be easily implemented.

  DESCRIPTION OF SYMBOLS 1 ... Electric motor, 2 ... Magnetic pole position estimator, 3 ... Magnetic pole position sensor, 4 ... Magnetic pole position detector, 5 ... Initial position corrector, 6 ... Inverter, 9 ... Power supply.

Claims (6)

A rotor magnetic pole position of the motor is measured by supplying a high frequency voltage or current for detecting the magnetic pole position of the rotor to a motor having electrical saliency on the rotor and measuring a response current or voltage of the motor. Magnetic pole position estimating means for estimating
A magnetic pole position sensor for detecting the magnetic pole position of the electric motor;
Magnetic pole position detecting means for obtaining the magnetic pole position from the output signal of the magnetic pole position sensor;
An initial position correcting means for obtaining a difference between the magnetic pole position estimated value from the magnetic pole position estimating means and the magnetic pole position obtained by the magnetic pole position detecting means, and providing the difference as a correction value;
Using the correction value provided from the initial position correcting means, correcting the magnetic pole position signal obtained from the magnetic pole position detecting means, and driving the electric motor based on the corrected magnetic pole position;
An electric motor control device comprising:   2. The electric motor control apparatus according to claim 1, wherein the magnetic pole position estimating means estimates the magnetic pole position a plurality of times and outputs an average value thereof as the magnetic pole position estimated value.   The magnetic pole position estimation means performs estimation of the magnetic pole position a plurality of times, excludes an estimated value exceeding a preset variation range, and outputs an average value of the remaining estimated values as the magnetic pole position estimated value. The motor control device according to claim 1.   The initial position correcting means, when the inverter drives the electric motor based on the corrected magnetic pole position, the magnetic pole position estimated value obtained from the magnetic pole position estimating means and the magnetic pole position obtained from the magnetic pole position detecting means. The motor control device according to claim 1, wherein a failure diagnosis of the magnetic pole position sensor is performed based on a difference from a position. A rotor magnetic pole position of the motor is measured by supplying a high frequency voltage or current for detecting the magnetic pole position of the rotor to a motor having electrical saliency on the rotor and measuring a response current or voltage of the motor. Magnetic pole position estimating means for estimating
A magnetic pole position sensor for detecting the magnetic pole position of the electric motor;
Magnetic pole position detecting means for obtaining the magnetic pole position from the output signal of the magnetic pole position sensor;
A correction means for obtaining a difference between the magnetic pole position estimation value from the magnetic pole position estimation means and the magnetic pole position obtained by the magnetic pole position detection means, and correcting the magnetic pole position using the difference as a correction value;
Based on the magnetic pole position corrected by the correction means, an inverter that drives and controls the motor;
An electric motor control device comprising: Supplying a high frequency voltage or current for detecting the rotor magnetic pole position of the electric motor to the electric motor, measuring a response current or voltage of the electric motor, and estimating the rotor magnetic pole position based on the measured value;
Providing a difference between a magnetic pole position detection value of a magnetic pole position sensor for detecting a magnetic pole position of the electric motor and the magnetic pole position estimation value as a correction value;
Correcting the magnetic pole position detection value from the magnetic pole position sensor based on the correction value;
Driving the electric motor based on the corrected magnetic pole position detection value;
An electric motor control method comprising:

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