轨道交通直流牵引供电系统线路测试回路短路试验案例分析OA

In order to study the influence of DC current direction on the line test circuit in the case of grounding short circuit,the principle of line test function of rail transit traction power supply system is introduced in detail.The short circuit test case of the line test circuit of Xilao Station of Guangzhou Metro Line 1 and the forward and reverse current test of the contactor are analyzed.The results show that the reverse current of the line test loop affects the internal arc of the contactor,resulting in long arc time and easy to burn the contactor.Moreover,the arc collision superposition leads to the short connection of two pairs of contacts in the contactor,that is,1 500 V bus short circuit.Therefore,the circuit test circuit must be connected correctly and short-circuit test must be completed to ensure normal function.