Rail transit power supply selective grounding leakage protection control device and control method

Abstract

The invention discloses a rail transit power supply selective grounding leakage protection control method. The method comprises the following steps: numbering traction substations; setting an alarm current setting value, a fault tripping voltage setting value and a fault tripping current setting value; judging whether a grounding leakage protection device detects that the leakage voltage and the leakage current reach a fault tripping setting value or not; sequentially judging whether an in-station positive electrode earth leakage fault and an interval positive electrode contact rail earth leakage fault occur in the traction substation or not; and judging whether a grounding leakage protection device detects the leakage voltage and the leakage current reaches an alarm current setting value, and judging whether a station or an interval reaches an alarm or tripping condition by combining the ground wire current of the contact rail. According to the invention, whether the uplink and downlink positive pole track contact rail has electric leakage can be judged, only a fault station or a station adjacent to a fault interval is selectively alarmed or tripped, and other stations do not alarm or trip, so that the troubleshooting time is saved, and the labor intensity of maintainers is reduced.

Description

technical field [0001] The invention relates to a selective grounding leakage protection control device and a control method for rail transit power supply. Background technique [0002] Straddle-type monorail trains and maglev trains use positive contact rail and negative contact rail for power supply. The positive contact rail and negative contact rail are installed with insulation to the ground. When the insulation of the positive contact rail is damaged, it will leak to the ground, and the leakage current must be connected to the ground wire of the contact rail. It flows through the earth leakage protection device (64D) located in the substation and flows back to the negative electrode. Most of the existing earth leakage protection devices are voltage type protection devices. A set of grounding is installed between the negative busbar of each traction substation and the ground. Leakage protection device, the voltage of the voltage sensor SV1 reaches 170v and alarms. When ...

AI Technical Summary

Problems solved by technology

[0002] Straddle-type monorail trains and maglev trains use positive contact rail and negative contact rail for power supply. The positive contact rail and negative contact rail are insulated from the ground. It flows through the ground leakage protection device (64D) installed in the substation and returns to the negative pole. Most of the existing ground leakage protection devices are voltage type protection devices. Leakage protection device, the voltage sensor SV1 voltage reaches 170v alarm, when the SV1 voltage reaches 200v, it will trip, which is equivalent to the one-way current sensor SA1 current at 34A alarm, when the one-way current sensor SA1 current reaches 40A, it will trip, because each station The negative busbars of each station are connected, and the grounding resistance and line resistance of each station are not much different, so the ground potential of each station is not much different. Therefore, when a leakage fault occurs, many stations will trip, and even cause the entire line of operation to trip, causing the operation For major accidents, the scope of troubleshooting after the event is extensive, the workload of maintenance is heavy, and the impact is great

[0003] The existing ground leakage protection device also has a positive and negative current difference comparison method. It is necessary to install four current sensors with a large difference of several thousand amperes at the feeder switch and negative isolating switch of each station. It is difficult to accurately distinguish small leakage currents, and the structure is complex and safe. low, easy to misjudge

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