Study On The Arc Extinction Scheme Of Dc Circuit Breaker For Metro System

The subway with relatively obvious advantages is popular in many large or medium cities as the first choice to solve traffic congestion problems. However, the DC circuit breaker used in existing subway DC power supply system is easily burned in extreme short-circuit fault situation, which has a negative impact on the maintenance and operation of the subway. Therefore, to solve the problem, the paper based on the arc extinction and simulation study on the commutation principle. The simulation shows that the arc extinction schemes of DC circuit breaker can effectively prevent the arcing and protect the contact of the DC circuit breaker. It provides a theoretical basis.The Paper study on the variety of the arc extinction schemes of DC circuit breaker for subway system. In order to break short faults, the arc extinction scheme of the commutation principle is relatively better. The arc extinction can be divided into three stages of the DC circuit breaker according to circuit theory.1. Short fault happens, and main interrupter opens;2. Sub-interrupter closes, and transfer current is devoted, which forces current to zero;3. After zero, the arc in main interrupter is extinguished, and the capacitance is energized by system. The simulation analyse the three stages above based on the data from real survey and study of the subway DC power system.The theoretical simulation can’t simulate the process, which the arc extinction in the contact of the DC circuit breaker. Therefore, the circuit introduce simulation model of Mayr arc, do research more accurate on the real circuit of the DC circuit breaker based on the Matlab platform.The simulation points out that the arc extinction schemes of DC circuit breaker can effectively prevent the arcing and protect the contact of the DC circuit breaker.Adopting simultaneous operation with a single machine of the permanent magnetic actuator is improved on the basis of traditional structure, we can make sure the main circuit breaker’s opening and the current’s transferring synthetically. The actuator principle of DC circuit breaker are analysed and simulated in the magnetic fields by Ansoft Maxwell. It provides a basis for the actuator for further research.