The Improvement Research On The Permanent Magnet Actuator Of The 12kV Vacuum Circuit Breaker

Smart grid has become the inevitable direction of the electric power system development and reform in our country and even the world, meanwhile intelligent distribution network is the key research object. Vacuum circuit breaker for permanent magnetic actuator is a switch device with a variety of advantages which can be used as the major equipment in system control and protection link of the distribution network. The permanent magnetic actuator has the merits of quick action, smaller dispersion, high reliability which meet the requirements of vacuum circuit breaker very well. And permanent magnetic actuator is also the key component that decides the dynamic performances of the vacuum circuit breaker. This paper focuses on the study of permanent magnetic actuator on the base of the 12kV vacuum circuit breaker research, designs and manufactures the monostabtle permanent magnetic operating mechanism made from silicon steel material with smaller energy consumption, strong controllability and better performances for the needs of the future circuit breaker development.The main purpose of this paper is to design and manufacture a low energy consumption permanent magnet actuator which meets the technical requirements of the vacuum circuit breaker. The specific work is as follows:First of all, the mass and counterforce characteristics of the 12kV indoor vacuum circuit breaker is calculated to the actuator side to provide foundation and basis for the dynamic characteristics analysis of the actuator. Then the material use of the permanent magnet actuator is analyzed theoretically and the influences of the materials on the permanent magnet actuator characteristics are also analyzed. Secondly, by analyzing the simulation results of the low carbon steel permanent magnet actuator designed in this paper, we can see that it meets the requirements of the vacuum circuit breaker, then the magnetic field distribution during the operation of permanent magnetic actuator is analyzed. Then the model of the square permanent magnet actuator using silicon steel material is designed. The excitation power supply and main design parameters of the two are exactly the same to compare the influences of the materials on the permanent magnetic actuator. Square permanent magnet actuator made from silicon steel meets the mechanical performance requirements of vacuum circuit breaker completely. And the peak currents during opening and closing operation are both less than the simulation results of the circular actuator. Finally, the specific processing technology is determined, two monostabtle permanent magnetic actuator of different material are made and stalled in the experimental platform of the 12kV indoor vacuum circuit breaker in this experiment, the displacement sensor and the current transformer are used to measure the relationship graphic of stroke and time, current and time in the excitation coil of the permanent magnetic actuator respectively. By analyzing the results, it can be seen that opening and closing magnetizing currents of square permanent magnet actuator are only 1 / 3 of these of the circular permanent magnet actuator when they both meet the requirements of the vacuum circuit breaker, thus providing materials and testing basis that in the permanent magnetic actuator application, silicon steel is better than the low carbon steel. The analysis of the material characteristics impacts on the permanent magnetic actuator is confirmed.