JPH05292781A - Motor driver provided with current phase correcting function - Google Patents

Abstract

PURPOSE:To obtain a driver having current phase correcting function which can drive a brushless servo motor at high rotational speed. CONSTITUTION:Current control section 9 in a motor driver comprises a current reference signal generating circuit A12 generating current reference signal Ic' corresponding to the rotor angle of a motor 4, a phase difference detecting circuit 13 operating phase difference between the current reference signal Ic' and a current feedback signal If, and a current reference signal generating circuit 14 generating a current reference signal Ic having a corrected phase difference DELTAtheta, and the motor 4 is driven at a high rotational speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless servomotor driving device.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional general brushless servomotor (hereinafter abbreviated as "motor") extracted from, for example, "Control Motor Technology Utilization Manual" (Toshiba / Small Motor Study Group, published by Sogo Denshi Shuppansha). 3) is a block diagram of a driving device. In the figure, 1 is a converter for converting an AC power supply into a DC power supply, 2 is an inverter for supplying a current for driving a motor, 3 is a current detector for detecting an output current of the inverter 2, and 4 is connected to the current detector 3. A motor, 5 is a load attached to the motor 4, 5 is an angle detector attached to the motor 4, 7 is an angle detector control unit connected to the angle detector 5, 8 is a speed control unit, and 9 is speed. The current control unit 10 connected to the control unit 8 is a current reference signal generation circuit in the current control unit 9, and 11 is a pulse width conversion (hereinafter abbreviated as “PWM”) circuit in the current control unit 9.

Next, the operation will be described. An angle detector 6 is mechanically connected to the output shaft of the motor 4 to be controlled and outputs a rotation angle position signal SE of the rotor. The angle detector controller 7 processes the angle signal SE and outputs a rotor angle signal RA and a speed feedback signal SF. The speed control unit 8 uses the speed command SC and the speed feedback signal SF sent from the angle detector control unit 7 as input signals, and since the difference between both input signals becomes small, the motor 4
Calculates the torque that should be generated, and the result is the torque command T
Output as C. In the current reference signal generation circuit 9 of the current controller 9, the torque command TC and the rotor angle signal RA of the motor 4 sent from the angle controller 7 are used for each phase of the U phase, V phase, and W phase of the motor 4. Current reference signals Iuc, Iv
Calculate c and Iwc. The PWM circuit 11 receives the current reference signals Iuc, Ivc and Iwc and the current feedback signals Iuf, Ivf and I from the current detector 3 for each phase.
The gate signal SG for each switching element of the inverter 2 is converted based on the difference from wf. The inverter 2 is controlled by the gate signal SG and supplies a three-phase AC voltage having a phase matching the rotor angle of the motor 4 to the motor 4 by using the DC power output from the converter 1 as a power source.

[0004]

In the conventional drive device for the motor 4 as described above, the current actually flowing in the motor 4 is controlled by the voltage applied to the motor 4, and the time delay in the circuit and the rotor There was a problem that the output efficiency deteriorates at high speed rotation or high load due to the deviation between the phase of the current of each phase and the motor no rotor angle due to the movement of the electrical neutral point due to the armature reaction of ..

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a motor drive device which can reduce the deterioration of the output efficiency at the time of high rotation and high load and can be made compact. And

[0006]

The motor drive device according to the present invention has a function of keeping the rotor angle and the phase of the current flowing through the motor constant.

[0007]

The means for keeping the rotor angle of the motor and the current flowing through the motor constant in the present invention uses a current reference signal having a phase such that the winding of the motor generates a magnetic field perpendicular to the magnetic field generated by the rotor. Then, calculate the phase difference between this current reference signal and the detection signal of the current flowing in the motor,
A current reference signal is generated again from the calculation result, and the current flowing in the motor is controlled by this current reference signal.

[0008]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 to 9 and 11 are shown in FIG.
Is the same as that shown in. Reference numeral 12 is a current reference signal generation circuit A in the current control unit, 13 is a phase difference detection circuit in the current control unit, and 14 is a current reference signal generation circuit B in the current control unit.

Next, the operation will be described with reference to FIG. An angle detector 6 is mechanically connected to the output shaft of the motor 4 to be controlled and outputs a rotation angle position signal SE of the rotor. The angle detector control unit 7 processes the angle signal SE to process the rotor angle signal RA and the speed feedback signal SF.
Is output. The speed control unit 8 receives the speed command SC and the speed feedback signal SF sent from the angle detector control unit 7 as input signals, and calculates the torque that the motor 4 should generate in order to reduce the difference between the both input signals. , And outputs the result as a torque command TC. The current controller 9 sends this torque command TC to the current reference signal generation circuit A12 and the current reference signal generation circuit B14. Current reference signal generation circuit A12
Then, based on the torque command TC and the rotor angle signal RA of the motor 4 sent from the angle detector control unit 7, U of the motor 4 is calculated.
Current reference signals Iuc ′, I for each phase of V phase, V phase and W phase
Calculate vc 'and Iwc'. In the phase difference detection circuit 13, the current reference signals Iuc ′, Ivc ′ and Iwc ′ and the current feedback signals Iuf, Ivf from the current detector 3 are outputted.
And Iwf, the phase difference Δθ between these two types of signals is detected. In the current reference signal generation circuit B14, the torque command TC
From the rotor angle signal RA and the phase difference Δθ, the current reference signals Iuc, Ivc and Iwc are calculated by correcting the phase difference between the current flowing through the motor 4 and the rotor angle. The PWM circuit 11 converts the difference between the current reference signals Iuc, Ivc and Iwc and the current feedback signals Iuf, Ivf and Iwf into the gate signal SG for each switching element of the inverter 2. The inverter 2 uses the gate signal SG
Is controlled by the DC power supply, which is the output of the converter 1, as a power supply, and a three-phase AC voltage having a phase matching the rotor angle of the motor 4 is supplied to the motor 4.

[0010]

As described above, according to the present invention, the configuration of the current control unit controls the current supplied to the motor while correcting the phase of the current reference signal and the current that actually flows. The frequency characteristics in the closed loop can be improved without increasing the gain in the open loop, and the motor rotating at a higher speed than before can be controlled.

[Brief description of drawings]

FIG. 1 is a block diagram showing a motor driving device according to an embodiment of the present invention.

FIG. 2 is a timing chart of a current reference signal according to the present invention.

FIG. 3 is a block diagram of a conventional motor drive device.

[Explanation of symbols]

 1 Converter 2 Inverter 3 Current Detector 4 Brushless Servo Motor 5 Load 6 Angle Detector 7 Angle Detector Control Section 8 Speed Control Section 9 Current Control Section 10 Current Reference Signal Generation Circuit 11 PWM Circuit 12 Current Reference Signal Generation Circuit A 13th Phase difference detection circuit 14 Current reference signal generation circuit B

Claims (1)

[Claims] 1. A motor with a current phase correction function, which has a function of controlling a current phase of a brushless servomotor rotating at a high speed and keeping a rotor angle and a current phase of the brushless servomotor constant. Drive.