Controller Of Circuit Breaker Operating Mechanism Based On CPLD And Analysis And Design On Structural Optimization

With the progressing of the electron technique and the power electron technique as well as computer control technique is on the way for intelligence. A circuit breaker is an important protecting electric device. Thus, it's important for the actuator and its control unit's performance and reliability.The reasonable design of permanent magnetic operating mechanism is subject investigated recently. The traditional bi-stable structure makes the permanent magnetic actuator's body bigger and heavier. The fault is more cost and less retentiveness. Nowadays, the advantage of the electronic computer's numerical value make the reasonable design for traditional permanent magnetic actuator's structure approved.In addition, the controller of traditional permanent magnetic operating mechanism used artificial circuit made by discrete electronic component. Thus, it is necessary toOn the basis of predecessor, numerical analysis method is adopted for structure optimized. Meanwhile, the intelligent control device of operation mechanism with permanent magnetic actuator is designed based on CPLD.This paper presents bi-stable permanent magnetic actuator (PMA) for medium voltage circuit breaker. A great emphasis is taken in the first part of the article on the finite element magnetic field model. The finite element magnetic field model was built by ANSOFT software according to structural characteristic and actual condition of work for permanent magnet actuator. Finite element method is adopted to calculate the static magnetic field of bi-stable PMA, analyze retentiveness of two kinds of PMA and relation of structure, disposal mode and dimension of permanent magnetic material, get the optimization structure of permanent magnetic actuatorThe second part of the paper, Based on CPLD , the intelligent control device of operation mechanism with permanent magnetic actuator for vacuum circuit breaker is designed. The device can not only control opening /closing operation of circuit breaker, but also has the functions of under-voltage trip, closing/opening interlock for mal-operation.Then, the logic function of controlling circuit breaker is simulated. The experimental results of intelligent control device on a vacuum circuit breaker show the logic control function and driving are correct. The miniaturization and the maintenance free of permanent magnetic operating mechanism can be achieved by electronic controlling device.