Double-end grounding loop resistance test method without dismounting grounding wire

Abstract

The invention relates to a double-end grounding loop resistance testing method without dismounting a grounding wire. Comprising the steps that a constant-current source control module is used for ensuring constant large-current power output; a bridge measurement method is used for eliminating the influence of contact resistance on measurement; a 4 + 1 terminal wiring method is used, 4 is four test leading-out wires I +, I-, U + and U-, and a wiring mode with built-in voltage wires needs to be adopted during testing; '1' means that a clip-on ammeter branch is added for current shielding, the shunt current value of a parallel branch is tested and fed back to the calculation module, and the actual value of the main loop resistance of the tested circuit breaker is calculated. According to the invention, the influence of parasitic loop and test line resistance is effectively eliminated, and the loop resistance test can be completed without dismounting the grounding bar. The novel test method eliminates the risk of hurting people by induced electricity caused by dismounting the grounding bar, innovates the operation process of the GIS loop resistance test, and can significantly improve the on-site working efficiency.

Description

technical field [0001] The invention relates to a method for testing the resistance of a double-terminal grounding loop without dismantling the grounding wire, and belongs to the technical field of circuit breaker loop resistance testing. Background technique [0002] At present, when conducting the circuit resistance test of the circuit breaker, it is necessary to change the safety measures and untie the grounding point on one side of the circuit breaker. On the one hand, it needs to be reported to the dispatcher. Restoration will increase the workload while prolonging the working hours and equipment outage time; on the other hand, after the safety measures are changed, the grounding point on one side of the circuit breaker will be released, which will pose a safety risk, especially for the internal circuit breaker of GIS. It is very close, and the safety risk of dismantling the grounding point on one side is great. For the 500kV circuit breaker loop resistance test, the p...

AI Technical Summary

Problems solved by technology

The loop resistance test is performed by applying a test current through the grounding switches on both sides when the circuit breaker is closed. Since the grounding switches will form parallel branches and cause shunts to affect the measurement results, the traditional test method needs to remove one of the grounding points , after eliminating the parallel loop, accurate measurement

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