Permanent Magnetic Vacuum Circuit Breaker Online Monitoring And Synchronous Closing

The paper introduces a kind of intellectual control technology of the vacuum circuit breaker with monostable permanent magnetic actuator. It bases on a practical project in power system.The synchronous closing for PMA is discussed in this paper. According to calculation, synchronous closing can reduce the value of current and over-voltage in the closing transient process. The closing of vacuum circuit breaker is taken as an example to analyze movement process of synchronous closing. It also analyzes the impact of pre-strike characteristic, environmental temperature and control voltage on synchronous closing.Many experiments have been pursued to measure the closing time under different temperature and control voltage by the control system designed in the paper, and a lot of experiment data has been gained. Some of them are used to train and establish a BP neural net, and the others are used to test the function of the neural net. The establishment of the model creates an advantageous condition for the realization of synchronous closing.We study the control scheme of the synchronous closing. There, microcomputer control system continuously adapt voltages, currents, temperatures and so on, and it compute the zero cross of the voltage when get the close command. Thereby, we get the sending time of control signals. Combining with electrified railway's specifies, we study and develop vacuum circuit breaker in the basis of intelligent phase control, and adapt permanent magnetic monostability operating institution, in terms of intelligent control technique, select phase rationally, control closing's angle. It debases the impact of over voltage and inrush current.