The Study Of Permanent Magnetic Actuator Of Middle-voltage Circuit Breaker

As a kind of new Actuator of Circuit Breaker, Permanent Magnetic Actuator (PMA) has the advantage of less parts, higher reliability and no maintenance and so on, so it has been paid more and more attention by people all over the world.In the paper, the mostly work is the study on Middle-voltage Circuit Breaker PMA ,its principle, the static characteristic, the dynamic characteristic and the control system. In the calculation of static magnetic field, the Finite Element Method (FEM) is used. The force characteristic of PMA with exciting current and without exciting current are calculated and analyzed. Because the dynamic character of PMA is affected by permanent magnet and exciting current, in this paper, new mathematic model and equation are established and the calculation result is analyzed. The data of exciting current, magnetic force, Moving-core velocity, Moving-core displacement and capacitance voltage at any time during opening and closeing operation and every factor's effect on dynamic character are obtained. Through the communication between PC and ATMEL 89C52 as the central processing unit, the control system had been intellectualized. In order to enhance the anti-jamming ability of control system, a lot of work has been done both on hardware and on software.