Existing DC circuit breakers are prone to overvoltage and high current during arc extinguishing,and this phenomenon brings great harm to equipment and circuit.In order to solve the problems of existing circuit breakers,a new improvement scheme is put forward.Based on the existing DC circuit breakers,the arc extinguishing function was enhanced by adding the peripheral auxiliary circuits.The peripheral circuit consists of a resistor in series with a capacitor,and then in parallel with a resistor.When the circuit breaker was opened,the current in the circuit breaker was absorbed by the resistor and capacitor series branch in the peripheral circuit to extinguish the arc.Afterwards,the capacitor released energy through the parallel resistance circuit.The Mayr arc model was established by Matlab software to simulate the circuit breaker before and after the improvement,and the simulation results were analyzed.The analysis shows that the arc extinguishing effect of the improved circuit breaker has been significantly improved,which verifies the correctness of the scheme.On this basis,a small scale experiment was done,and the experimental results were analyzed.The analysis results verify the correctness of the simulation,and also further verify the feasibility of the scheme.%现有直流断路器在灭弧时容易产生过电压和大电流现象,此现象给设备和线路带来了很大危害.针对现有断路器存在的主要问题,提出了一种新的改进方案,以现有直流断路器为基础,通过设计增加外围辅助电路来加强灭弧功能.外围电路主要由一个电阻和一个电容串联再与一个电阻并联而成,开断断路器时,由外围电路中电阻和电容串联支路吸收断路器中的电流,来熄灭电弧;事后,电容通过并联电阻回路释放能量.通过Matlab软件建立Mayr电弧模型对断路器改进前后进行仿真,并对仿真结果进行分析,通过分析得到改进后断路器比改进前在灭弧效果上有了明显的提高,验证了方案的正确性;在此基础上做了小型实验,并对实验结果进行分析,通过实验分析结果验证了仿真的正确性,同时也进一步验证了方案的可行性.
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