Synchronous Control Technology of Vacuum Circuit Breaker: An Exploratory Study

Permanent magnetic actuator, for its various advantages such as high motion reliability and time accuracy, lays the foundation for the development of the synchronous control technology of circuit breaker. This paper designs a synchronous controller for the vacuum circuit breaker of 126kV. First of all, it identifies the principles and basic requirements of the synchronous control technology, based on which the grid signals are pre-processed. Secondly, white noises are removed and interfering signals are filtered by FIR digital filter so that signal zero can be accurately detected by applying the linear interpolation method. Then, the mathematical model for closing time under different voltages and temperatures are established using BP neural network technique. Later, weight and threshold are adjusted by applying L-M algorithm to conduct basic training and test for the neural network so that the opening and closing times can be compensated. Finally, FFT (fast Fourier transform) is used to calculate signal frequency and phase. Then the synchronous controller f the design undergoes the accuracy test. The result shows that the error of synchronous control is limited to less than ±1ms.