Brake-phase short-circuit detecting, judging and protecting device

The utility model relates to a braking-phase short-circuit detecting, judging and protecting device which comprises a fault detecting and judging mechanism and a chain-protection implementing mechanism. The input end of the fault detecting and judging mechanism is connected with positive and negative buses and two ends of a braking resistor, and the fault detecting and judging mechanism is used for detecting the voltages of the buses and the voltages on two ends of the braking resistor; fault signals are output when the judging result shows that a braking-phase discharge tube is subjected to short circuit; the input end of the chain-protection implementing mechanism is connected with the output end of the fault detecting and judging mechanism, and the output end is connected with a control switch, wherein the control switch is connected in series with the loop formed by the braking resistor, the braking-phase discharge tube and the positive and negative buses; and when the fault signals are received, the control switch is switched off.. The braking-phase short-circuit detecting, judging and protecting device can automatically judge the short circuit of the braking-phase discharge tube and switches off the loop formed by the braking resistor, the braking-phase discharge tube and the positive and negative buses so as to prevent the barking resistor from continuous power supply to cause heating, outbreak even overburning and protect the equipment.