Research On The Control System Of Electromagnetic Operation Mechanism Of Locomotive Vacuum Circuit Breaker

In the context of the rapid development of high-speed railways in China,the intelligentization of locomotive vacuum circuit breakers has become a hot issue in research.Synchronous control is one of the intelligent development directions of locomotive vacuum circuit breakers,and the dispersion of operating time of the operating mechanism is the main factor affecting the accuracy of synchronous switching.Therefore,it is of great significance to reduce the dispersion of locomotive vacuum circuit breaker action time through the research of control system.This thesis takes the new electromagnetic operation mechanism of locomotive vacuum circuit breaker as the control object.The dynamic characteristics of the closing process are analyzed.Considering the characteristics of locomotive operation,voltage and ambient temperature are the main reasons that lead to the dispersion of electromagnetic mechanism movement time,and the influence of the above two factors on the electromagnetic mechanism movement time is studied,and study the influence of the above two factors on the action time of the electromagnetic mechanism.Studies have shown that the effect of voltage and temperature changes on the action time are achieved by changing the excitation coil current,the excitation coil current can be controlled to reduce the variability of the locomotive vacuum circuit breaker operating time.Secondly,the research contents mainly include: a mathematical model of a new electromagnetic operating mechanism was established,select the full-bridge circuit topology as the energy storage capacitor discharge circuit,a hysteresis control system was built in Simulink,control the excitation coil current of the electromagnetic mechanism.Simulation results show that under ideal conditions,the hysteresis control which can stabilize the closing time of the electromagnetic mechanism at around 34 ms when the voltage and temperature change,reduces the dispersion of electromagnetic mechanism action time.Considering the inherent delay of the system,the actual excitation coil current fluctuation becomes larger,which affects the closing action characteristics of the electromagnetic operating mechanism.Finally,in order to reduce the impact of system delay on the control system,the model prediction method is used to control the full-bridge circuit.The simulation results of a model predictive control system show that after adding the system delay,the actual current of the excitation coil can still accurately follow the reference current,and the feasibility of predictive controller to reduce the dispersion of electromagnetic mechanism action time is verified.And the predictive control system controls the switching frequency at different current amplitudes,thereby reducing the overall switching loss of the system.