The Development Of Synchronization Circuit Breaker Based On Permanent Magnetic Mechanism

In recent years, leading subject of the study of intelligent vacuum switch is synchronousswitch, which is also known as phase selection control switch or phase control switch. thesynchronous control is used widely in electric power system to control and reduce switchingtransients，increase the interrupting capacity of switches，improve the reliability of electricpower system．Starting from the research of the principle of synchronous controlling technology,thispaper firstly expounds the process of synchronous closing and synchronous opening of thePMA(permanent magnetic actuator),analyses the method of phase selecting and the technicalelement for synchronous closing；then the impact of pre—strike characteristic，environmentaltemperature and controlling voltage on synchronous closing and corresponding resolutionsWas analyzed，at the same time，analyses how the synchronous closing reduce the value ofover-current and over-voltage in the closing transient process．In synchronous breaking of the single-phase ground fault currents.Firstly,using theTaylor series simplified mathematical model of fault current,then the primary object ofcontrolled short-circuit interruption is predicting the zero point of fault electric currentexactly. The parameters of short circuit current is extracted based on the least mean squaresalgorithm in order to predict the zero crossing of the fault currents as targets forsynchronizing the opening command to the circuit breaker so as to obtain the bestinterruption moment.Finally, the two key technologies---Signal extraction and predicted synchronouscontrol’s zero points of opening or closing time. Detail as follows: through FIR filtereliminating interfering signals，and obtaining the zero point of the reference signal，a BPneutral network model was established for forecasting the operating time，Then using thegenetic algorithm to optimize BP neural network prediction error,until make it moredesirable.and the which Can fulfill the requirement of high accuracy and fast constringency；all of these provided the foundation for the realization of synchronous control．...