A ground fault simulation device for power DC system

Abstract

The invention relates to a ground fault simulation device for an electric power direct current system. The ground fault simulation device for the electric power direct current system comprises rotary switches SA1-SA4, resistors R1-R18, capacitors C1-C14, an adjustable transformer T and an alternating current 220V power supply GJ. The ground fault simulation device for the electric power direct current system has the advantages that complex ground faults of various types can be simulated flexibly and safely by using a direct current bus or direct current branches of a field direct current power supply system, and the ground fault simulation device is convenient to mount and operate; alternating current invasion simulation can be further carried out on the direct current bus or all the direct current branches, alternating current electricity jumping faults such as PT alternating current voltages and 380V alternating current low voltages in an electric power system can be simulated, and alternating current measuring and recording functions of an insulation monitoring device can be detected; an interlocking method is adopted by the rotary switches in the ground fault simulation device, and the safety and the reliability in the ground fault simulation process are ensured.

Description

technical field [0001] The invention belongs to the technical field of DC system grounding faults in electric power systems, and relates to a grounding fault simulation device for electric DC systems. Background technique [0002] The DC power supply part of the power system is composed of battery packs, charging equipment, DC panels and other equipment. The DC system provides reliable DC power for control, signal, relay protection, automatic devices, telecontrol communication devices, etc. in power plants and substations, and provides emergency lighting power. It also provides reliable operating power for operation. Whether the DC system is reliable or not plays a vital role in the safe operation of power plants and substations, and is the guarantee for the safe operation of power plants and substations. [0003] The grounding of DC systems in power plants and substations is a fault that is prone to occur and is very harmful to the power system. Among DC ground faults, t...

AI Technical Summary

Problems solved by technology

In the DC grounding fault, the most harmful is the two-point grounding, which may cause serious consequences

If the positive pole of the DC system is grounded, there may be a possibility of relay protection malfunctioning, because the general tripping coil (such as the export intermediate relay coil and tripping coil, etc.) is connected to the negative pole of the power supply, and if the circuit is grounded again or the insulation is poor, it will form a two-point grounding , causing malfunction of the protection; if the negative pole of the DC system is grounded, if there is another point of grounding in the circuit, two points of grounding can be formed to short-circuit the trip circuit or closing circuit, causing relay protection, signals, automatic devices to malfunction or refuse to operate, or cause The DC fuse is blown, so that the protection, automatic device and control circuit will lose power

In a complex protection circuit, two points of the same pole are grounded, and some relays may be short-circuited, and the protection cannot be tripped, resulting in refusal to operate, resulting in a leapfrog trip

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