Line selection device and protection non-fault-trip prevention cooperation small current grounding fault processing method

Abstract

The invention discloses a line selection device and protection non-fault-trip prevention cooperation small current grounding fault processing method, and belongs to a power system relay protection field. The line selection device and protection non-fault-trip prevention cooperation small current grounding fault processing method comprises steps that step 1001, the line selection device is used to determine a faulted line; a step 1002, the line selection device is used to control the trip-out of the faulted line; step 1003, the non-fault-trip prevention closing is executed; step 1004, the line selection device is used to determine whether the fault after the trip-out disappears; step 1005, the determining of the faulted line is wrong; step 1006, the determining of the faulted line is right; step 1007, whether the fault occurs again is determined; step 1008, the faulted line is restored; step 1009, a trip-out and non-fault-trip prevention locking instruction is transmitted; step 1010, the faulted line is isolated. The line selection device and protection non-fault-trip prevention cooperation small current grounding fault processing method is advantageous in that after the faulted line is determined by the line selection device, a trip-out operation circuit is directly controlled, and by adopting the cooperation between a trip-out control circuit and the non-fault-trip function of the protection device, the isolation of the small current grounding fault is realized.

Description

technical field [0001] The invention relates to a small current grounding fault handling method in which a line selection device and a protection anti-stealing trip are coordinated, and belongs to the field of relay protection of electric power systems. Background technique [0002] After a single-phase ground fault occurs in a small current grounding system, the line insulation pressure increases due to the increase of the non-fault phase voltage. Arcing overvoltages can also cause equipment damage in the event of intermittent arcing ground faults. Long-term operation with faults is also likely to cause electric shock accidents for humans and animals. Therefore, after the small current ground fault line selection device selects the faulty line, it should trip after a period of delay to cut off the faulty line. Since the current line selection device cannot achieve 100% correct rate of line selection at the first time, and some small current grounding faults can be self-he...

AI Technical Summary

Problems solved by technology

This mode of operation cannot restore power supply to faults that can be self-healed by tripping and extinguishing the arc, resulting in reduced power supply reliability

When the line selection device selects the wrong line, the non-faulty line will be tripped by mistake and cannot be recovered, further reducing the reliability of power supply

[0004] Patent application number 201410109169.0 "A method for self-adaptive tripping of small current grounding faults" provides the conditions for self-adaptive tripping, and monitors the reliability of fault line selection results, line insulation conditions, and fault severity through online real-time monitoring, and comprehensively considers line types, According to the load's demand for power supply reliability, etc., adaptively select whether and when the faulty line trips, but the patent does not involve the implementation logic of tripping

[0005] Patent No. ZL201520271576.1 "A Small Current Grounding Line Selection Tripping and Reclosing Device" proposes the logic of tripping and closing through the circuit of the line selection device itself, but most of the current practical applications are that the line selection device passes through the line protection device and its reclosing The brake function realizes tripping and closing, or the line selection device directly controls the tripping operation circuit, and generally does not directly control the closing operation circuit. This patent does not provide the coordination logic and control method of the line selection device and the line protection device

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