JP2002369570A - Motor control method and unit thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide the control method of a motor, having high safety for discharging the charge in a smoothing capacity which is charged, using the magnetic pole position sensor output of a rotor. SOLUTION: Since a motor is energized so that a q-axis current is minimized using a CS sensor signal, that is outputted for each electrical angle of 60 degrees, the charge of the smoothing capacitor 2 is consumed by subjecting it to sinusoidal energization nearly at 180 degrees with patterns -1, -0.5, 0.5, 1, 0.5, and -0.5 to a U-phase coil, and patterns 1, 0.5, -0.5, -1, -0.5, and 0.5 in reverse rotational direction to CS1 signal output 0, 1, 1, 1, 0, and 0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for discharging a charge of a smoothing capacitor provided in a DC power supply of a motor control device when the motor is stopped.

[0002]

2. Description of the Related Art Generally, a DC power supply of a motor control device is provided with a smoothing capacitor. When the input of the capacitor is interrupted in a charged state and the power supply to the motor is stopped, the electric charge of the smoothing capacitor is removed from the safety point of view. Must be discharged, D
A method of discharging using a C / DC converter or discharging using a resistor has been considered.

[0003] In addition, the control method of the driving motor is such that, as a sensor for detecting the magnetic pole position of the rotor mounted on the motor, a CS signal output every 60 electrical degrees and an encoder signal composed of multiple pulses are used. Utilizes motor control.

When an encoder signal that does not output an absolute position is used, the motor drive is controlled by a rectangular wave according to the output of the CS signal until a reference position is input.

[0005]

However, when discharging the electric charge of the above-mentioned conventional charged smoothing capacitor,
If component parts are required separately from motor drive control,
When the motor is energized and discharged only by the S signal, a torque is generated in the motor, so that the discharge using the motor cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a safety in discharging a charge of a smoothing capacitor charged by using an output of a magnetic pole position sensor of a rotor necessary for driving and controlling a motor. It is an object of the present invention to provide a low cost motor control method.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a three-phase motor provided with a sensor having a phase difference of 120 degrees in electrical angle from each other to detect a magnetic pole position of a rotor, and an electric motor of the sensor. A motor control device that performs drive control according to a sensor signal output every 60 degrees is provided.The motor control device includes an input circuit breaker connected to one of the DC outputs and a smoothing capacitor connected to the inverter unit. When the power supply to the motor is stopped by the operation of the input circuit breaker, the power is supplied to the motor so as to minimize the q-axis current component and the electric charge of the smoothing capacitor is discharged.

[0008]

In order to solve the above-mentioned problems, a method for controlling a motor according to the first aspect of the present invention comprises:
Motor control device comprising: a three-phase motor having a sensor having different degree phases and detecting a magnetic pole position of a rotor; and a motor control device for performing drive control in accordance with a sensor signal output at every 60-degree electric angle of the sensor. Has an input circuit breaker connected to one of the DC outputs and a smoothing capacitor connected to the inverter section. When the input circuit breaker stops the current supply to the motor, the motor is energized so that the q-axis current component is minimized. To discharge the charge of the smoothing capacitor,
The charge of the smoothing capacitor can be discharged while minimizing the generated torque without using a separate component such as a C-DC converter.

Further, the motor control method according to claim 2 is
When the input circuit breaker is activated and the motor is turned off, CS
For the signals 0,1,1,1,0,0, the phase coil
Since electricity is supplied in the following pattern: 1, -0.5, 0.5, 1, 0.5, -0.5 or 1, 0.5, -0.5, -1, -0.5, 0.5 In addition, the discharge current can be supplied with a substantially sine wave, the vibration at the time of discharge can be minimized, and the charge of the smoothing capacitor can be discharged.

The motor control method according to claim 3 is
When the input circuit breaker is activated and the motor is turned off, CS
For the signals 1,1,1,0,0,0, the phase coil
1,0,1,1,0, -1 or 1,0, -1, -1, -1,
Since current is supplied in the pattern of 0 or 1, the driving current at the time of driving the motor can be substantially sinusoidal, the vibration at the time of driving the motor can be minimized, and the charge of the smoothing capacitor can be discharged at the time of discharging.

The motor control method according to claim 4 is
Since the energization pattern of the phase coil is alternately reversed every certain period and energized, the torque generated by energizing the discharge current in a rectangular waveform with respect to the ideal d-axis current can be minimized,
Vibration at the time of discharge can be reduced, and the charge of the smoothing capacitor can be discharged.

Further, in the motor control method according to the present invention, the sensor is an encoder comprising a CS signal for outputting a rotor magnetic pole position every electrical angle of 60 degrees and a multi-pulse, and detects an abnormal state of each signal. The sensor is individually detected and energized so that the q-axis current component is minimized using the sensor signal output normally, so that it is possible to avoid the situation where either sensor is abnormal and the smoothing capacitor cannot be discharged, and the charge of the smoothing capacitor is discharged. it can.

Further, any one of claims 1 to 5
By using a motor drive device using the motor control method described in the section, a highly safe and inexpensive motor drive device can be provided.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, 1 is an input circuit breaker, 2 is a smoothing capacitor, 3 is an inverter section for supplying electricity to a motor, 4 is a driven three-phase motor, and a sensor 5 for detecting a magnetic pole position of a rotor. Built-in. 6 is a control unit,
An energization command to the three-phase motor 4 is calculated in accordance with an input from the sensor 5 and various input signals, and the drive of the three-phase motor 4 is controlled by controlling the inverter unit 3.

The input circuit breaker 1 cuts off the input when an abnormality occurs or the inverter stops, and stops the power supply to the inverter unit 3. When the input circuit breaker 1 is turned on, the smoothing capacitor 2 is charged, Thereafter, when the input is turned off (cut off) by the input circuit breaker 1, the smoothing capacitor 2 is kept charged.

FIG. 2 is a flowchart for explaining the discharge control of the smoothing capacitor according to the present invention. First, the state of energization to the motor is determined by whether the input circuit breaker is operating (cut off). If not, continue motor drive control,
If the input circuit breaker is operating, the operation shifts to discharge control. Then, the motor is energized so as to minimize the q-axis current component in accordance with a motor driving pattern described later, thereby discharging the electric charge of the smoothing capacitor.

In FIG. 3, ideal q-axis currents of the U, V, and W phase coils (solid lines) and ideal d-axis currents of the U, V, and W phase coils (dotted lines) are shown. V, W
It is a d-axis conduction waveform of a phase coil. FIG. 4 shows the conduction waveforms (rectangular waves in oblique lines) of the U-, V-, and W-phase coils with respect to the ideal q-axis currents (solid lines). The d-axis current is 90 degrees out of phase with the q-axis current. Therefore, no torque is generated even when the d-axis current is applied to the motor, and is used for discharge control.

Here, the output signal of the sensor for detecting the position of the magnetic pole of the rotor, and the energization pattern at the time of driving the motor and at the time of discharge control, which are features of the present invention, will be described.

FIG. 5 (a) illustrates the output signals of the CS sensor. The signals CS1 to CS3, which differ in phase by 120 electrical degrees from each other, are 0, 1, 1 every 60 electrical degrees. , 1, 0, 0, and each phase of the three-phase motor is energized based on each CS signal.

As an example of the rectangular wave drive, U
The energization pattern of the phase will be described. C in FIG.
When the S1 signal output is 0, 1, 1, 1, 0, 0, FIG.
In order to make the U-phase coil approximate to the ideal q-axis current, the U-phase drive current of FIG.
A current of 120 degrees is applied in the order of 1, 0, -1, -1, 0 (FIG. 4
Shaded area). If the rotation direction is reversed, 0, -1,-
Energization is performed at 120 degrees in the order of 1,0,1,1,0. V phase, W
Similarly, the phases are CS2 and C
The S3 signal output is energized.

When the input circuit breaker is activated during rectangular wave driving and the power supply to the motor is cut off, the smoothing capacitor is charged as described above, so that there is a danger of accidental touching.

Therefore, in order to minimize the generated torque while discharging the electric charge of the smoothing capacitor, an ideal d-axis current having a phase shifted by 90 degrees from the ideal q-axis current of the U-phase coil may be applied. A signal having a phase shift of 90 degrees from each CS output signal cannot be generated.

Therefore, as in the present invention, for the CS1 signal output 0, 1, 1, 1, 0, 0, the U-phase coil has -1,
A 180-degree substantially sinusoidal wave is applied in a pattern of -0.5, 0.5, 1, 0.5, and -0.5 (shaded portion in FIG. 3). Also, if the rotation direction is reversed, 1,0.5, -0.5, -1,-
Electricity is supplied in a 0.5, 0.5 pattern. Thereby, the electric charge of the smoothing capacitor can be consumed.

Since the above-described energization pattern is merely approximated to the ideal d-axis current component, the q-axis current component can be surely minimized by inverting the current pattern alternately at certain intervals.

As described above, when the open / close state of the input circuit breaker is monitored and the cut-off signal is detected, if the motor is energized in the energizing pattern described with reference to FIG. .

(Embodiment 2) Hereinafter, Embodiment 2 will be described with reference to the drawings.

FIG. 6 is a flowchart for explaining the discharge control of the smoothing capacitor according to the second embodiment. The state of energization to the motor is determined by whether the input circuit breaker is operating (cut off). If it is not operating, the motor drive control is continued. If the input circuit breaker is operating, it is determined whether the CS sensor is abnormal or the encoder signal is abnormal. If both are abnormal, the process ends without energization. If at least one of them is normal, the motor is energized so that the q-axis current component is minimized in accordance with the energization pattern described later to discharge the electric charge of the smoothing capacitor.

The second embodiment is effective for reducing vibration during motor drive control, and outputs CS1 to CS3 output at every 60 degrees of electrical angles having a phase difference of 120 degrees from each other.
The U-phase energization pattern for CS1 will be described as an example of the energization pattern.

The output of the CS1 signal shown in FIG.
For 1,0,0,0, the ideal q for the U-phase coil of FIG.
In order to approximate the shaft current, the U-phase driving current in FIG. 7B is normalized to 0.5, 1, 0.5, -0.5,-
180-degree substantially sine-wave conduction (hatched portion in FIG. 9) is performed in the order of 1 and -0.5. If the rotation direction is reversed, -0.5, -1,
A 180-degree substantially sinusoidal wave is supplied in the order of -0.5, 0.5, 1, 0.5. The V-phase and the W-phase are also energized for the CS2 and CS3 signal outputs only with a difference of the electrical angle of 120 degrees.

In FIG. 8, the ideal q-axis currents of the U, V, W-phase coils (solid lines) and the ideal d-axis currents of the U, V, W-phase coils (dotted lines) are shown. V, W
It is a d-axis conduction waveform of a phase coil. FIG. 9 shows the conduction waveforms (substantially sine waves in the hatched portions) with respect to the ideal q-axis currents (solid lines) of the U, V, and W phase coils. Here, Example 1
Similarly to the above, the d-axis current is 90 degrees out of phase with the q-axis current, so that no torque is generated even when the d-axis current is applied to the motor, and the d-axis current is used for discharge control.

In order to minimize the generated torque while discharging the electric charge of the smoothing capacitor, an ideal d-axis current having a phase shift of 90 degrees from the ideal q-axis current of the U-phase coil may be applied. A signal that is 90 degrees out of phase from the CS output signal cannot be generated.

When the motor is controlled by using an encoder signal composed of a CS signal for each electrical angle of 60 degrees and a multi-pulse as a signal output from the sensor, the state of the sensor signal is normal or abnormal. The state is individually monitored, and when the input is cut off and the smoothing capacitor is discharged, the motor is energized using the normal signal so that the q-axis current component is minimized.

Therefore, in the second embodiment, when the CS signal is normal, the CS-signal output 1,1,1,0,0,0 is applied to the U-phase coil at the time of discharging by -1,0,1,1. , 0, -1
The pattern is energized by 120 degrees (shaded area in FIG. 8). If the rotation direction is opposite, 1,0, -1, -1,0,1
Energize in the pattern of Thereby, the electric charge of the smoothing capacitor can be consumed.

Further, by alternately inverting the above-described energization pattern at certain intervals, the torque generated by the discharge current can be minimized, vibration during discharge is suppressed, the q-axis current component is minimized, and the smoothing capacitor is discharged. can do.

[0036]

As apparent from the above embodiment, according to the first aspect of the present invention, the motor magnetic pole position sensor output necessary for driving and controlling the motor is used, and the motor is energized by operating the input circuit breaker. And a highly safe motor control method capable of discharging the charge of the smoothing capacitor charged when the motor stops.

According to the second aspect of the present invention, the discharge current can be made substantially sinusoidal, so that vibration at the time of discharge can be minimized.

Further, according to the third aspect of the present invention, the driving current at the time of driving the motor can be substantially sinusoidal, the vibration at the time of driving the motor can be minimized, and the electric charge of the smoothing capacitor can be discharged at the time of discharging. it can.

According to the fourth aspect of the present invention, since the power is supplied while being alternately inverted every certain period, the torque generated by the discharge current can be surely minimized.

According to the fifth aspect of the present invention, the current is supplied so that the q-axis current component is minimized using the sensor signal output normally, so that either of the sensors is abnormal and the smoothing capacitor cannot be discharged. Can be avoided, and the charge of the smoothing capacitor can be discharged.

As described above, since the energization pattern for the discharge control is formed based on the output of the magnetic pole position sensor of the rotor necessary for drive control of the motor, the configuration can be made inexpensive. It is possible to realize a highly safe and inexpensive motor drive device which can suppress the discharge and realize a highly safe discharge control.

[Brief description of the drawings]

FIG. 1 is a control configuration diagram according to an embodiment of the present invention.

FIG. 2 is a flowchart according to the first embodiment of the present invention.

FIG. 3 is a conduction waveform diagram at the time of discharging in Example 1 of the present invention.

FIG. 4 is an energization waveform diagram during driving according to the first embodiment of the present invention.

FIG. 5 is an energization pattern diagram at the time of motor driving and discharging with respect to a CS sensor signal according to the first embodiment of the present invention.

FIG. 6 is a flowchart according to a second embodiment of the present invention.

FIG. 7 is an energization pattern diagram for a CS sensor signal during motor driving and discharging according to a second embodiment of the present invention.

FIG. 8 is a conduction waveform diagram at the time of discharge in Embodiment 2 of the present invention.

FIG. 9 is an energization waveform diagram during driving according to the second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input circuit breaker 2 Smoothing capacitor 3 Inverter part 4 Three-phase motor 5 Rotor magnetic pole position detection sensor 6 Control part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H560 AA08 BB04 BB12 DA02 DA07 EB01 JJ03 JJ17 JJ19 SS01 TT10

Claims (6)

[Claims] 1. A three-phase motor provided with a sensor that detects a magnetic pole position of a rotor that has a phase difference of 120 degrees in electrical angle with respect to each other, and drives and controls the sensor in accordance with a sensor signal output every 60 degrees of electrical angle of the sensor. A motor control device, the motor control device includes an input circuit breaker connected to one of the DC outputs, and a smoothing capacitor connected to the inverter unit. When the input circuit breaker stops energizing the motor, the q-axis A motor control method characterized by discharging a charge of a smoothing capacitor by energizing a motor so that a current component is minimized. 2. When the input circuit breaker operates and the motor energization is stopped, the CS signals 0, 1, 1, 1, 0, 0
-1, -0.5,0.5,1,0.5,-
0.5 or 1,0.5, -0.5, -1, -0.5,
The motor control method according to claim 1, wherein the current is supplied in a pattern of 0.5. 3. When the input circuit breaker is activated and the motor energization is stopped, the CS signals 1,1,1,0,0,0 are
-1,0,1,1,0, -1 or 1,0,
2. The motor control method according to claim 1, wherein the power is supplied in a pattern of -1, -1, 0, 1. 4. The motor control method according to claim 2, wherein the energization pattern of the phase coil is alternately reversed every certain period to energize. 5. The sensor detects the position of the rotor magnetic pole by an electrical angle of 6.
An encoder composed of a CS signal output at every 0 degree and a multi-pulse, wherein an abnormal state of each signal is individually detected, and a q-axis current component is minimized using a normally output sensor signal. The motor control method according to any one of claims 1 to 4, wherein the motor is energized. 6. A motor drive device using the motor control method according to claim 1. Description: