MAIN CIRCUIT GROUNDING PROTECTION METHOD FOR DIRECT-CURRENT ELECTRIC TRANSMISSION DIESEL LOCOMOTIVE

摘要

Main circuit grounding protection method for a direct-current electric transmission diesel locomotive. The method comprises: transmitting a signal DJ_IN of a grounding relay DJ and signals dI₁-dI_n of leakage current sensors S1-Sn to a microcomputer controller by means of a signal detection interface module; when the signal DJ_IN is at a high level and the signals dI₁-dI_n are all less than a given value dI, the microcomputer controller outputting a grounding relay resetting signal DJ_Ctrl so as to reset the grounding relay DJ; if the DJ_IN is at a low level after resetting, a locomotive continuing operating according to normal working conditions; if the reset grounding relay DJ continues operating, outputting an LCBK_Ctrl signal to control the turn-off of an excitation loop contactor and unloading of a diesel engine; and when the signal DJ_IN is at a high level, if the signal dI_i is greater than dI, outputting the BKi_Ctrl signal to turn off the contactor BKi, and simultaneously outputting the DJ_Ctrl signal to reset the grounding relay DJ. The quick diagnosis and localization during grounding can be realized, the reliability of the locomotive is improved, a device is effectively protected, problems are discovered in advance, a grounding device is properly cut off, and the traction power of the locomotive can be retained to the maximum limit.