For the traction power supply system with dedicated rail served as the return circuit, the negative return rail has good insulation characteristics to the earth, greatly limiting the short circuit current generated by positive earthing faults. Due to reasons of voltage drop and great earthing resistance of the negative busbar, the existing positive earthing protection has exposed the problems of poor selectivity and low sensitivity in the actual application. The paper, on the basis of the analyzing of the power flow of short circuit current and load current of the traction power supply system with dedicated rail for current return, proposes that the sum of feeder currents of power supply section shall be taken as the characteristic variables for diagnosis of positive earthing faults. A protection scheme based on this fault characteristic variable is designed, and the effectiveness of the protection scheme with the sum of feeder currents in the power supply section served as the characteristic variables for the fault diagnosis is verified by application of the MATLAB/Simulink simulation system.
关键词
专用轨回流牵引供电系统/负母线接地回路/馈线和电流/MATLAB/Simulink
Key words
traction power supply system with dedicated rail served as return circuit/negative busbar earthing circuit/sum of feeder currents/MATLAB/Simulink
维普
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