Research Of Controller For Permanent Magnetic Actuator

This paper makes an investigation on controller for permanent magnetic (PM) actuator.As the main equipment for delivering and controlling electric power, the traditional design and control mode of electric devices and switch apparatus must be changed, so to adapt to the modern power system and the modern industry production as well as the social developing trend. With the progressing of the electron technique and the computer technique as well as information processing technique, the switch apparatus is on the way for intelligence. A circuit breaker, as an important protecting electric device, must not only perform the basic function of protect and control, but also gradual add the functions of on-line monitoring and trouble diagnosis. So as to say, the actuator and its control unit's performance and quality plays an very important role for a high Voltage circuit breaker's performance and reliability. Until 1990's the permanent magnetic actuator appears internationally as a driving mechanism for high Voltage circuit breaker. It adopts one kind of totally new working theory and mechanism, combining the electric magnetic mechanism with the permanent magnet well, overcoming the bad affect of non-reliable movement of the mechanical tripping/locking device in the opening/closing position, using the electric magnetic holding force produced by permanent magnet to keep the vacuum circuit breaker in the opening/closing position, in the same time, using the electron technique and the power electron technique as well as computer control technique to improve and perfect the control unit, It is especially for the realization of the switch apparatus's intelligence.This paper makes an analysis and investigation on the electric wear of the contact in the vacuum arc-chutes. It has established one kind of mathematic model for estimating the contact's residual life, and it has pointed out to use the FFT for decomposing the instant value of the cutoff current so as to acquire its steady state periodic component.This controller compound with periphery circuit adopts PIC16F877 to perform the intelligent control and make making and switching of PM actuator much more credible. It uses power storage electric capacity to provide exciting current of in making/interrupting electric coilto accomplish opening/closing operation. It adopts Electronic switch being composed of IGBT to control the opening/closing coil current. Display circuit adopts 8 bits LED drive PS7219 with high-speed serial interface to realize display. This control device designs long-distance input output circuit to achieve long-distance control.Principle of main component, design thought, circuit diagram of every part, model choice and numerical value count of main component is presented in hardware design part. Flow chart and design thought of main and subprogram is presented in software design part.