JPS60245492A - Speed controller of motor - Google Patents

Abstract

PURPOSE:To enhance the controlling accuracy and the stability of a motor by using the integrated value of a real speed instead of the real speed when a speed response becomes the set value or larger. CONSTITUTION:When the speed response becomes a value alpha or higher set by a speed response setter 20, a relay 18 is operated by a calculator 17, an output from the calculator 17 for amplifying a deviation between the output omega'm of an integrator 16 for integrating the real speed omegam and a speed command value omega*m is input to a calculator 8 by converting a deviation between a speed command value omega'm and a speed feedback omegam to the output of a calculator 7 for amplifying the deviation. Thus, the hunting phenomenon of a control system is suppressed to improve the stability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a control device used for controlling the speed of an electric motor.

[Conventional technology]

As a conventional device of this kind, for example, the Journal of the Institute of Electrical Engineers of Japan 10
There was something like Figure 1 in Volume 3, No. 9, P884 (24).

A conventional device of this type is shown in FIG. In the figure, (1) is a DC power supply, (2) is an inverter main circuit that converts DC power to tributary power, (3) is a variable voltage variable frequency device main circuit, (4) is an induction motor to be controlled,
(5) is the roll that is the load of the electric motor (5), +61 is the speed detector, (7) is the operational amplifier for comparing the speed reference and speed feedback, and (8) is the output of the operational amplifier (7). , speed feedback, and a circuit that generates the primary current reference of the induction motor from the magnetic flux current reference (91 is an operational amplifier for comparing the current reference and current feedback, and aα is an adder for calculating the V-phase current reference. (14) is the speed reference generation circuit, uS is the magnetic flux current reference. This is a generation circuit.

Next, the operation will be explained. When controlling the speed of an induction motor, a speed reference is generated by the speed reference generation circuit I, the speed deviation between this speed reference ω♂ and the speed feedback ωm is amplified by the operational amplifier (7), and it is applied to the secondary current reference circuit. 2".The amplification factor of the operational amplifier (7) at this time is set to the induction motor (4) and the roll (
Determined by GD2 etc. of 51.

This secondary current reference 12H and the magnetic flux current reference 1. A partial current reference 1'' is calculated and generated by the control circuit (8) from the speed feedback ωm and ωm.The deviation between this negative current reference 11'' and the partial current feedback 1 is amplified by the operational amplifier (9). Provided to the control circuit (17J) that controls the drive of the main circuit (2).

This control circuit (11) controls the voltage generated by the main circuit (2) to control the speed of the induction motor.

Conventional induction motor control devices are configured as described above, so due to gear backlash, the load (
When GD2 of electric motor (4) and roll (5) changes (electric motor GD2 - electric motor GD2 + roll GD2),
The speed response may change, which may cause a disturbance and cause the control system to lose stability. This is because since the amplification factor of the operational amplifier (7) is constant, the speed response changes with changes in GD2 of the load, resulting in a loss of stability in the control system.

[Summary of the invention]

This invention is intended to eliminate the drawbacks of the conventional ones as described above.When the speed response exceeds a set value, it uses the integral value of the actual speed instead of the actual speed. The purpose of this invention is to provide a control device for an induction motor that can configure a control system.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, (L61 is an integrator circuit for integrating the actual speed ωm, and (17) is an integrator circuit for integrating the actual speed ωm. When the speed exceeds the value α set by the speed response setter (a), the relay a mallet is activated to integrate the integrator circuit aQ. Amplify the deviation between the output ωm′ and the speed command value ω♂,
an arithmetic circuit (1) that outputs an output to be input to the arithmetic circuit (8);
9 is a control device for the induction motor.

Next, the operation of this invention will be explained. The operation when controlling the speed of an induction motor is the same as that of conventional devices, except that when the speed response exceeds the set value ζ:, control is switched from the actual speed to the integral value of the actual speed. . That is, it operates as follows.

For example, GD2 of electric motor (4) and GD2 of roll (5)
If the ratio of the speed operational amplifier (1) is constant, the speed response ωC will change by 1:60.For this reason, the speed will overshoot with respect to the speed reference ω♂. , resulting in the control system losing stability.
If the speed response is greater than the setting device, the calculation circuit (17)
Then, turn off the relay ■, and input the amplified deviation between the integrated value of the actual speed, which is the output of the calculation circuit (L7), and the speed command value to the calculation circuit (8) instead of the calculation circuit (7). do.

In this way, the hunting phenomenon of the control system can be suppressed and stability can be improved.

Further, in the above embodiment, the case of a transistor main circuit has been described, but the same effects as in the above embodiment can be obtained with other main circuit electrical switches.

Furthermore, the same effect can be achieved in DC machines and synchronous machines.

〔Effect of the invention〕

As described above; 2. According to the present invention, since the speed response is configured to be equal to or greater than the set value (if it becomes 2, the integral value of the actual speed is used instead of the actual speed), the control accuracy of the device is improved and the stability is improved. It has the effect of giving you something with high quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional speed control device for an induction motor, and FIG. 2 is a block diagram showing a speed control device for an induction motor according to an embodiment of the present invention. +11...DC power supply, (2)...Inverter main circuit, (3)...Variable voltage variable frequency device main circuit, (4)
...Induction motor, (5)...Roll, (6)...
Speed detector, (7)...Operation amplifier, (8)...Primary current reference generation circuit for induction motor, 4 words...Magnetic flux current reference generation circuit, Integrator, ...Operation amplifier, or...Relay, (19...Motor speed control device, (A)...Speed response setting device. In addition, the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 2

Claims (1)

[Claims] A motor speed control device (=) that amplifies the deviation between the speed reference signal and the actual speed and forms a conductivity control loop so that the change in the above actual speed per time, that is, the actual speed fluctuation rate, is A speed control device for an electric motor, characterized in that when the speed fluctuation rate becomes larger than the speed fluctuation rate, the actual speed signal is integrated and the deviation between the actual speed signal and the speed reference signal is amplified to control the speed of the electric motor.