KR900002526A - Power saving device of induction motor - Google Patents

Abstract

No content

Description

Power saving device of induction motor

Since this is an open matter, no full text was included.

1 is a circuit diagram showing, in some block form, a preferred embodiment of the present invention suitable for a power saving device of a three-phase induction motor.

Claims (4)

A contactless alternating current switch means 10 connected in series with an induction motor, a feedback signal generating means 12 for supplying an output proportional to a phase difference between a motor current and a voltage, and a power factor command signal generating means for generating a power factor command signal 14 ) And control means responsive to the output of the feedback signal generating means 12 and the power factor command signal to control the switching state of the switch means 10, wherein the feedback signal generating means 12 A power saving device for an induction motor, characterized in that a feedback signal is generated from the motor voltage signal for a period from the start point of the cycle voltage of the motor voltage to the start point of the firing of the contactless switch unit (10). 2. The full-wave rectification shoe stage (12C) connected to the connection point between the contactless AC switch means (10) and the motor for full-wave rectification of the motor voltage signal, and the full-wave rectification. And a signal superimposing means (12D) for superimposing the electric motor voltage signal and the contactless AC switch means (10) of the control means and the firing angle control signal of the control means and outputting a clipping voltage of less than or equal to zero. Power saver. 3. The full-wave rectifying means (12C) is characterized in that the operational amplifier U1 is connected to the junction between the motor and the contactless switch means 10 through the diodes D1 and D2 of opposite polarities, respectively. Power saving device for a floating motor comprising a. Proportional to the phase difference between each phase current and voltage of the contactless AC switch means (10.30.50) respectively connected between each phase terminal (RST) of a three-phase power source and the corresponding phase terminal (UVW) of a three-phase induction motor. The feedback signal generating means (12.32.52) for supplying the output of the power source, the power factor command signal generating means (14) for generating the power factor command signal, and the feedback signal generation for controlling the switching state of the switch means (10.30.50) Wherein said feedback signal generating means (12.32.52) comprise said corresponding solid state AC switches (10.30), comprising control means responsive to the added feedback signal of means (12.32.52) and said power factor command signal. .50) and full-wave rectifying means (12C, 32C, 52C) connected to the connection points between the respective phase terminals (UVW) of the three-phase induction motor, respectively, for full-wave rectification of the motor voltage signal of each phase; Voltage signal and the control means Induction characterized in that it comprises a signal superimposing means (12D, 32D, 52D) for outputting by clipping the zero voltage or less overlapping each firing angle control signal corresponding to the non-contact AC switch means (10.30.50) Electric power saving device. ※ Note: The disclosure is based on the initial application.