JP2001112282A - Motor control device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When an abnormality occurs in a sensor of a synchronous motor of an electric vehicle or the like, sufficient safety cannot be ensured. A motor (2), a magnetic pole position detection sensor (3) for detecting a magnetic pole position of the motor (2), and an inverter unit (1) for controlling the driving of the motor (2) according to the detected magnetic pole position.
An abnormality detector 5 for detecting an abnormality of the magnetic pole position detection sensor 3, and a magnetic pole position estimator 6 for estimating a magnetic pole position of the motor 2 when the abnormality detector 5 detects an abnormality.
The inverter means 1 controls the driving of the motor 2 according to the magnetic pole position estimated by the magnetic pole position estimator 6 when the abnormality of the magnetic pole position detection sensor 3 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for driving a motor while ensuring safety when a sensor for detecting a rotational position of a synchronous motor is abnormal.

[0002]

2. Description of the Related Art In recent years, synchronous motors have been developed as drive sources for elevators, electric vehicles, and the like from the viewpoint of maintenance and high efficiency. Conventionally, this type of motor has been widely used for FA (factory automation) and industrial use, but in any case, the basic control method is almost the same. However, in the case of elevators and automobiles, there is a very high risk of human life, so it is necessary to consider fail-safe at the time of failure.

[0003] As a conventional fail-safe control device, for example, Japanese Patent Application Laid-Open No. Hei 7-87777 has been proposed. This technology stops the motor if the magnetic pole position detection sensor becomes abnormal while the motor is running, or
Abnormality occurs only in the A and B phase signals of the magnetic pole position detection sensor,
When the CS signal is normal, the magnetic pole position is detected using the CS signal, and the driving method of the motor is switched from sine wave driving to rectangular wave driving. This can prevent runaway of the motor and the like.

[0004]

Incidentally, in the case of a vehicle such as an elevator or an electric car, sudden stopping causes a high danger or inconvenience. Therefore, the vehicle is stopped after being moved to a predetermined position or a safe place. This leads to safety.

[0005] However, in the above-mentioned method, when a sensor abnormality occurs, the sensor is stopped so that there is a problem in securing safety. Further, even when the CS signal is normal, there is a problem that it becomes difficult to ensure sufficient safety due to vibration or the like due to rectangular wave driving.

The present invention provides a motor control device capable of performing motor control that can sufficiently secure safety even if a motor sensor malfunctions, in consideration of such a problem of motor drive in the case of a conventional sensor malfunction. The purpose is to do so.

[0007]

According to the present invention, there is provided a motor, a magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor, and a motor according to a magnetic pole position detected by the magnetic pole position detecting means. Inverter means for controlling the power supplied to the motor, sensor abnormality detection means for detecting an abnormality in the magnetic pole position detection means, and a motor rotor when the abnormality in the magnetic pole position detection means is detected by the sensor abnormality detection means. Magnetic pole position estimating means for estimating the magnetic pole position, wherein the inverter means supplies the motor to the motor according to the magnetic pole position estimated by the magnetic pole position estimating means when the sensor abnormality detecting means detects an abnormality in the magnetic pole position detecting means. This is a motor control device for controlling the power to be generated.

According to a third aspect of the present invention, there is provided a motor and magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor.
Inverter means for controlling electric power supplied to the motor according to the magnetic pole position detected by the magnetic pole position detecting means;
Sensor abnormality detection means for detecting abnormality of the magnetic pole position detection means, wherein the sensor abnormality detection means detects abnormality of at least the Z-phase signal output by the magnetic pole position detection means, and the inverter means comprises: Z by detection means
The motor control device continues the sine-wave drive or the rectangular-wave drive of the motor by using the CS signal output from the magnetic pole position detecting means when the abnormality of the phase signal is detected.

According to a fourth aspect of the present invention, there is provided a motor and magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor,
Inverter means for controlling electric power supplied to the motor according to the magnetic pole position detected by the magnetic pole position detecting means;
Sensor abnormality detecting means for detecting abnormality of the magnetic pole position detecting means, and magnetic pole position estimating means for estimating the magnetic pole position of the rotor of the motor when abnormality of the magnetic pole position detecting means is detected by the sensor abnormality detecting means. If the abnormality of the magnetic pole position detecting means is detected by the sensor abnormality detecting means during the steady operation of the motor, the inverter means stops the motor once and then again according to the magnetic pole position estimated by the magnetic pole position estimating means. It is a motor control device that controls electric power supplied to the motor.

According to a fifth aspect of the present invention, there is provided a motor, and magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor.
Inverter means for controlling electric power supplied to the motor according to the magnetic pole position detected by the magnetic pole position detecting means;
Sensor abnormality detecting means for detecting abnormality of the magnetic pole position detecting means, and magnetic pole position estimating means for estimating the magnetic pole position of the rotor of the motor when abnormality of the magnetic pole position detecting means is detected by the sensor abnormality detecting means. If the abnormality of the magnetic pole position detecting means is detected by the sensor abnormality detecting means at the time of starting the motor, the inverter means stops the motor once, and then, based on the magnetic pole position estimated by the magnetic pole position estimating means, returns to the motor. It is a motor control device that controls supplied electric power.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. (First Embodiment) FIG. 1 is a configuration diagram of a motor control device according to a first embodiment of the present invention. In FIG. 1, a motor control device according to the present embodiment includes a synchronous motor (hereinafter simply abbreviated as a motor) 2 and inverter means for driving and controlling the motor 2 by pulse width modulation (hereinafter abbreviated as PWM). 1 and the load current of the motor 2 or the induced voltage of the coil (here, the load current)
And a magnetic pole position detecting sensor 3 for detecting a magnetic pole position of a rotor of the motor 2.
A magnetic pole position calculator 4 for calculating a magnetic pole position based on an output signal of the magnetic pole position detection sensor 3, and an abnormality detector as sensor abnormality detecting means for detecting when an abnormality occurs in the detection of the magnetic pole position 5, a magnetic pole position estimator 6 for estimating a magnetic pole position using the output of the motor information detector 8 when the abnormality detector 5 detects an abnormality, and an operation of the abnormality detector 5. By switching the output signals of the magnetic pole position calculator 4 and the magnetic pole position estimator 6, the inverter means 1
And a sensor signal switching device 7 for outputting the same.

In the above configuration, the magnetic position detecting sensor 3
The magnetic pole position calculator 4 constitutes a magnetic pole position detecting means. Further, an encoder, a resolver, or the like can be used as the magnetic position detection sensor 3. From these sensors, an A-phase signal, a B-phase signal, a Z-phase signal, and a CS signal (C
S1 to CS3) are output. Here, the CS signal is a signal of the commutation sensor signal, which is a signal that detects the position of the magnetic pole of the rotor of the motor, and is used to detect the position of the magnetic pole of the rotor and determine which coil is energized. is there. Also, the Z-phase signal is generally one pulse per rotation in the case of an encoder, and one pulse per 360 degrees of electrical angle in the case of a resolver.
A pulse output is a reference pulse, and the A and B phase signals are
These are two-phase pulses that are 90 degrees out of phase. The phase difference is used to detect the direction of rotation.
The rotation angle of the rotor can be detected by counting the pulse train of the phase signal.

Here, the rotation angle is detected, for example, by counting only the rising edges of the A-phase signal and the B-phase signal, and assuming that 1000 pulses are generated per rotation, the 500th pulse counted from the Z-phase signal is the rotor pulse. Corresponds to 180 degrees. The rotation speed is detected by counting the number of pulses of the A-phase signal or the B-phase signal within a certain time interval, thereby detecting the speed of the motor. For example, if 2,000 pulses are counted per second, it means that the motor rotates twice per second, which means that the motor rotates at 120 rpm.

As described above, the rotation angle of the rotor basically seems to be unnecessary if the Z-phase signal, the A-phase signal, and the B-phase signal are present. However, the Z-phase signal, the A-phase signal, and the B-phase signal can be effectively used after the reference Z-phase signal is input.
Commutation to the coil is performed according to the signal output.

FIG. 2 is a diagram showing an example of the configuration of the inverter means 1 shown in FIG. That is, the inverter unit 1 includes a speed conversion unit 18 that converts a sensor signal from the sensor signal switch 7 into a speed signal,
A speed control unit 11 that outputs a speed control command signal based on the output of the motor and a torque command that is input, a sensor signal switch 7
An address generation unit 17 that generates a digital address signal corresponding to the rotor position of the motor 2 based on the sensor signal from the motor 2, a U-phase for driving the motor 2 based on the address signal from the address generation unit 17, A waveform storage unit 16 for reading out the W-phase waveform data, an integration D for adding the waveform data from the waveform storage unit 16 and the speed control command from the speed control unit 11 and performing digital-to-analog conversion on the addition result. A / A converter 12 and an error signal between the U-phase and W-phase output signals of the integrating D / A converter 12 and the detection signal of the load current of the motor 2 from the motor information detector 8,
Current control unit 13 that outputs phase, V-phase, and W-phase current instruction signals, a PWM control unit 14 that generates a pulse width modulation signal in accordance with an output signal of the current control unit 13, and a PWM control unit PWM for driving motor 2 according to output signal
It is composed of an inverter.

Next, the operation of the motor control device of the above embodiment will be described with reference to the drawings.

FIG. 3 is a flowchart showing a basic operation in the motor control device according to the present embodiment. FIG.
First, when an abnormality of the magnetic pole position detecting means is detected by the abnormality detector 5, an abnormality signal is generated (Step S).
11). Next, upon receiving the abnormal signal, the sensor signal switch 7
Switches the sensor signal in accordance with the type of the sensor signal in which the abnormality has occurred (step S12). Thereafter, an effective driving method is selected based on the switched sensor signal, and the driving control of the motor 2 is continued (step S1).
3). Details of the above operation will be described below.

FIG. 4 is a block diagram showing a configuration example of the abnormality detecting section. In FIG. 4, A and B phase signals, Z phase signals, and CS1 to CS3 which are sensor outputs of the magnetic pole position detection sensor 3.
Each signal of the CS3 signal and each inverted signal of the signal are input to the waveform processing unit 21, and waveform processing such as waveform shaping is performed.

The waveform-processed A and B phase signals are
It is counted by the OWN counter 22 and output to the address generation means 30. Also, the CS1 to CS3 signals are
The signals are output to the CS edge detector 27, the CS abnormality detector 28, and the magnetic pole position detector 29, and the CS1 signal is sent to the counter 25. The Z-phase signal is output from the Z-phase abnormality detector 23, Z
It is output to the phase switch 24 and the counter 25.

FIG. 5 shows an example of a motor having 6 P poles and A / B phase pulses of 1000 pulses / rotation.
As shown in (a), Z rises every three rises of CS1.
Since a pulse is generated, the counter 25 counts three CS1 pulses, detects whether or not a Z pulse is generated at the third count by the Z-phase abnormality detector 23, and outputs a Z-phase abnormality signal. The Z-phase switch 24 receives the Z-phase abnormality signal and outputs an address reset signal to the address generation means 30. In addition, as shown in FIG. 5B, the CS edge detector 27 generates a CS edge of 9 pulses per one rotation of the motor from the signals CS1 to CS3 and outputs the CS edge to the A and B phase abnormality detector 26. On the other hand, since the AB phase edge generates a total of 4000 pulses per rotation, 40 pulses are generated between CS edges.
00/18 = 222 pulses. Therefore, the AB-phase abnormality detector 26 counts the number of AB-phase edges between CS edges, and the number is 222 ± α (α is, for example, 10).
Is out of the range, an AB phase abnormality signal is output. In addition, the CS abnormality detector 28 observes the state of the CS1 to CS3 signals, and when all are “H” or “L”, the CS abnormality is detected.
Outputs an abnormal signal.

As described above, when an abnormality is detected in the Z-phase signal, the A-phase signal, the B-phase signal, and the CS signal, the following processing is performed according to the type of the signal in which the abnormality has occurred. In FIG. 6, when an abnormality is detected in the magnetic pole position sensor signal by the abnormality detector 5 (step S20), a driving method of the motor 2 corresponding to the type of the sensor signal in which the abnormality has occurred is selected.

First, when the Z pulse does not occur at the third count of the CS1 pulse and the Z-phase signal is abnormal (step S27), the count is cleared by the rising edge of the CS1 signal (step S28). As a result, the address generation means 30 can read the address corresponding to the rotation angle of the rotor, and the sine wave drive based on the waveform data stored in the waveform storage unit 16 is continued (step S29).

Next, the AB-phase abnormality detector 26 counts the number of AB-phase edges between CS edges, and the number is 2
If the AB phase abnormal signal is output out of the range of 22 ± α (step S24), the magnetic pole position is detected by the CS signal (step S25), and the rectangular wave driving means (not shown) performs rectangular detection based on the CS signal. Continue driving with waves. Alternatively, the magnetic pole position is estimated from the time between the CS edges, and the operation by the sine wave drive is continued (step S2).
6).

If a CS signal abnormality is detected by the CS abnormality detector 28 (step S21), the position of the magnetic pole is estimated using the information of the motor information detector 8, and the sensor signal is switched (step S22). Then, the operation is continued by the sensorless drive (step S23).

Examples of the sensorless drive include an induced voltage detection method (see Japanese Patent No. 2819655) and a method based on a current estimation error (“sensorless brushless DC motor control based on a current estimation error”, T. IEEE JA).
PAN, Vol. 115-0), and the former,
Detects the induced voltage of the drive coil of each phase of the motor, generates a reference phase pulse by comparing the induced voltage with a reference potential, sets a delay time based on the reference phase pulse, and sets the delay time. The power supply to each drive coil is switched according to the delay time. In the latter, the position and speed are estimated by focusing on the fact that the direction of the speed electromotive force corresponds to the rotor position and the magnitude thereof corresponds to the speed, and a mathematical model of the motor is provided inside the controller. By calculating an estimated current based on the estimated position and the estimated speed electromotive force, and using the error between the estimated current and the actual current of the motor detected by the current detector to identify the position and speed electromotive force, the motor Speed control.

As described above, according to the motor control device of the present embodiment, even if an abnormality occurs in the magnetic pole position detection sensor during the operation of the motor, the abnormality does not stop suddenly and the abnormality further occurs. Depending on the type of the sensor signal, sine wave driving can continue the same operation as usual. So, for example,
Unexpected sudden stops in elevators and automobiles do not occur, and safety can be ensured. (Second Embodiment) FIG. 7 is a flowchart showing an operation in a second embodiment according to the present invention. The basic configuration of this embodiment is the same as that of the first embodiment. This embodiment corresponds to a case where an abnormality of the magnetic pole position sensor occurs when the motor is rotating at high speed.

In FIG. 7, when a CS signal abnormality occurs,
Although sensorless driving is performed, the accuracy of estimating the magnetic pole position is low in this method. However, the field-weakening control performed at the time of high-speed rotation controls the phase of energization with high accuracy, and field-weakening control without a sensor is difficult. Therefore, when an abnormality of the magnetic pole position sensor is detected in the abnormality detection processing (step S31) and an abnormality signal is generated, the rotation speed of the motor is reduced to a predetermined value Nr.
In order to reduce the speed to pm, the PWM control is temporarily stopped and the power supply to the motor is stopped (step S32). PWM
After the control is stopped, it is detected whether or not the rotation speed of the motor has become smaller than a predetermined value Nrpm (step S33).
When the speed becomes lower than pm, the sensor signal is switched (step S34), the PWM control is started again (step S35), and the sensorless drive is performed to continue the operation.
With this method, even if a sensor error occurs during high-speed rotation of the motor, the sensor speed drops to a speed at which sensorless driving is possible, and the motor is driven again. On the other hand, it is possible to operate while maintaining the operation state. (Third Embodiment) FIG. 8 is a flowchart showing an operation in a third embodiment according to the present invention. The basic configuration of this embodiment is the same as that of the above-described first embodiment. In the present embodiment, as in the first embodiment, a case where an abnormality of the magnetic pole position sensor occurs when the motor is rotating normally, but an IGBT (insulated gate) is used as a switching element of the PWM inverter. IGB when using a bipolar transistor)
It corresponds to one for preventing the destruction of T or protecting the magnet from demagnetization. Here, IGBT is MOSFE
It combines the advantages of T and a bipolar transistor, and has low power consumption at the gate, making it suitable for applications such as motor drivers.

In FIG. 8, in order to prevent the IGBT from being destroyed or to protect the magnet from being depleted, the abnormality detection processing (step S41) detects an abnormality in the magnetic pole position sensor, and when an abnormality signal is generated, the PWM control is performed once. It stops (step S42). After the PWM control is stopped, the number of rotations of the motor is detected to check whether the motor has stopped (step S43). After the motor has been stopped, the sensor signal is switched (step S44), and the PWM control is restarted. Then, the operation is restarted by performing sensorless driving (step S45).

Also, even when the motor is initially started, if an abnormality occurs in the magnetic pole position sensor, the IGBT may be destroyed or the magnet may be demagnetized. When a sensor abnormality is detected and an abnormal signal is generated, the PWM control is temporarily stopped, and after confirming that the motor has stopped, the sensor signal is switched to restart the PWM control, and the sensorless drive is performed to resume operation. By doing so, the IGBT can be prevented from being broken, or the magnet can be protected from demagnetization.

As described above, the motor control device according to the present embodiment cannot be applied to a device in which a sudden stop is unexpectedly troublesome, but a short stop is acceptable, but it is necessary to start the operation immediately. It can be applied to such a device.

In each of the above embodiments, an encoder or a resolver that outputs A and B phase signals, a Z phase signal, and CS1 to CS3 signals is assumed as the magnetic pole position detection sensor. Instead, the present invention can be applied to a configuration using a CS (commutation) sensor that outputs only a CS signal.

Further, in the above-described embodiment, it is assumed that the present invention is applied to an elevator or an electric vehicle. However, the present invention is not limited to this, and is applicable to various vehicles using a synchronous motor other than the electric vehicle or to a propulsion drive unit. The present invention can be applied to any other transporting device as long as it uses a motor.

In each of the above embodiments, C
Although the sensorless drive is performed only when the S signal is abnormal, the configuration is not limited to this, and the sensorless drive may be performed when another sensor signal is abnormal.

In the encoder and the resolver, C
Some types do not output the S signal, but the same effect can be obtained by performing sensorless driving when the sensor is abnormal.

[0035]

As is apparent from the above description, the present invention has an advantage in that even if an abnormality occurs in a sensor of the motor, the motor can be controlled with sufficient safety.

Further, according to the present invention, if the motor is rotated at such a high speed that the magnetic pole position cannot be estimated, the magnetic pole position is estimated after the speed is reduced. There is an advantage that safety can be sufficiently ensured in the event that an abnormality occurs in the sensor.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a motor control device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating an example of an inverter unit according to the first embodiment.

FIG. 3 is a flowchart showing a basic operation in the first embodiment.

FIG. 4 is a configuration diagram illustrating an abnormality detection unit according to the first embodiment.

FIG. 5 is a timing chart illustrating an abnormality detection method according to the first embodiment.

FIG. 6 is a flowchart illustrating an operation of an abnormality detection unit according to the first embodiment.

FIG. 7 is a flowchart illustrating an operation according to the second exemplary embodiment of the present invention.

FIG. 8 is a flowchart illustrating an operation according to the third exemplary embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inverter means 2 Synchronous motor 3 Magnetic pole position detection sensor 4 Magnetic pole position calculator 5 Abnormality detector 6 Magnetic pole position estimator 7 Sensor signal switch 8 Motor information detector 11 Speed control unit 13 Current control unit 14 PWM control unit 15 PWM inverter 17 Address Generation Unit 23 Z-Phase Abnormality Detector 26 A, B-Phase Abnormality Detector 27 CS Edge Detector 28 CS Abnormality Detector 29 Magnetic Pole Position Detector

Claims (9)

[Claims] A motor; magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor; inverter means for controlling electric power supplied to the motor in accordance with the magnetic pole position detected by the magnetic pole position detecting means; Sensor abnormality detecting means for detecting abnormality of the magnetic pole position detecting means, and magnetic pole position estimating means for estimating the magnetic pole position of the rotor of the motor when the sensor abnormality detecting means detects abnormality of the magnetic pole position detecting means The inverter means controls the power supplied to the motor in accordance with the magnetic pole position estimated by the magnetic pole position estimating means when the sensor abnormality detecting means detects an abnormality in the magnetic pole position detecting means. A motor control device. 2. When the rotation speed of the motor is equal to or greater than a predetermined value when the sensor abnormality detection unit detects an abnormality in the magnetic pole position detection unit, the inverter unit sets the rotation speed to the predetermined value. Until the rotation speed of the motor reaches the predetermined value, and then controls the power supplied to the motor according to the magnetic pole position estimated by the magnetic pole position estimating means. The motor control device according to claim 1, wherein: 3. A motor, magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor, and inverter means for controlling electric power supplied to the motor in accordance with the magnetic pole position detected by the magnetic pole position detecting means. Sensor abnormality detection means for detecting abnormality of the magnetic pole position detection means,
The sensor abnormality detection means detects abnormality of at least the Z-phase signal output from the magnetic pole position detection means, and the inverter means detects that the abnormality of the Z-phase signal has been detected by the sensor abnormality detection means. In this case, the motor control device continues sine-wave driving or rectangular-wave driving of the motor by using a CS signal output from the magnetic pole position detecting means. 4. A motor, magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor, and inverter means for controlling electric power supplied to the motor in accordance with the magnetic pole position detected by the magnetic pole position detecting means. Sensor abnormality detecting means for detecting abnormality of the magnetic pole position detecting means, and magnetic pole position estimating means for estimating the magnetic pole position of the rotor of the motor when the sensor abnormality detecting means detects abnormality of the magnetic pole position detecting means When the abnormality of the magnetic pole position detecting means is detected by the sensor abnormality detecting means during the steady operation of the motor, the inverter means temporarily stops the motor and then again stops the magnetic pole position. A motor control device for controlling electric power supplied to the motor according to the magnetic pole position estimated by the estimating means. 5. A motor, magnetic pole position detecting means for detecting a magnetic pole position of a rotor of the motor, and inverter means for controlling electric power supplied to the motor in accordance with the magnetic pole position detected by the magnetic pole position detecting means. Sensor abnormality detecting means for detecting abnormality of the magnetic pole position detecting means, and magnetic pole position estimating means for estimating the magnetic pole position of the rotor of the motor when the sensor abnormality detecting means detects abnormality of the magnetic pole position detecting means In the case where an abnormality of the magnetic pole position detecting means is detected by the sensor abnormality detecting means at the time of starting the motor, the inverter means temporarily stops the motor and then again returns to the magnetic pole position estimating means. A motor control device that controls electric power supplied to the motor in accordance with the magnetic pole position estimated by (1). 6. The magnetic pole position detecting means includes: an encoder;
The motor control device according to any one of claims 1, 2, 4, and 5, further comprising one of a resolver and a commutation sensor. 7. A transport device using the motor control device according to claim 1 for a propulsion drive unit. 8. An electric vehicle using the motor control device according to claim 1 for a propulsion drive unit. 9. An elevator, wherein the motor control device according to claim 1 is used for a drive unit.