Ground protection method for main circuit of DC electric drive diesel locomotive

摘要

#$%^&*AU2016304615A120180125.pdf#####3 Abstract of Description The invention discloses a ground protection method for the main circuit of a DC electric drive diesel locomotive. The signal DJIN of a grounding relay DJ and the signals dljid of 5 leakage current sensors Si l-Sn are transmitted into a microcomputer controller through a signal detection interface module. When the signal DJIN is at high level and signals dJid 1 are all smaller than a given value dl, the microcomputer controller outputs grounding relay resetting signal DJCtrl to reset the grounding relay; if DJIN is at low level after resetting, the locomotive continues to run under normal conditions; if the grounding relay DJ continues to act 10 after resetting, LCBKCtrl signal is output to control an excitation circuit contactor to be off, and the diesel engine unloads; when signal DJIN is at high level, if signal dI; is larger than the dl, BKi_Ctrl signal is output to open the contactor BKi, and meanwhile DJCtrl is output to reset the grounding relay DJ. Rapid diagnosis and positioning can be achieved during grounding, reliability of the locomotive is improved, and equipment is effectively protected. 15 Problems are found in advance, grounding equipment can be cut off aptly, and locomotive traction power can be reserved maximally.