Low-current grounding system single-phase earth fault circuit selection method

Abstract

The invention provides a low-current grounding system single-phase earth fault circuit selection method. The method comprises the following steps: (1) inputting a pull-limit electric sequence table; (2) arranging a one-key sequential control program used for single-phase earth fault circuit selection in the line monitoring platform; (3) setting a grounding fault exploration operation sequence table in the one-key sequential control program, and setting an automatic sorting rule of the grounding fault exploration operation sequence table; (4) setting a ground fault exploration criterion in theone-key sequential control program; 5, calling a one-key sequential control program; (6) generating a ground fault exploration operation final sequence table; and (7) automatically carrying out circuit breaking to search a ground fault circuit. The invention provides a new single-phase earth fault line selection method for a small-current grounding system, and the method can be used for conveniently, quickly and efficiently troubleshooting a line with a single-phase earth fault of the small-current grounding system, thereby greatly improving the fault line searching and accident processing efficiency.

Description

technical field [0001] The invention relates to the field of processing methods for grounding faults in distribution networks, in particular to a method for pulling and selecting lines for single-phase grounding faults in a small current grounding system. Background technique [0002] At present, most of the domestic distribution networks are small-current grounding systems, and the neutral point is not directly grounded (including the neutral point is not grounded and the neutral point is grounded through the arc suppression coil). The low-current grounding system has a very high probability of single-phase grounding faults. When a fault occurs, the symmetry of the line voltage can still be guaranteed due to the power supply, and the fault current is small, which does not affect the continuous power supply of the load. It is not necessary to cut off the power immediately under normal conditions. However, with the increasing number of distribution network feeders, the capaci...

AI Technical Summary

Problems solved by technology

[0003] The traditional single-phase grounding fault line troubleshooting method of small current grounding system is to send an order from the power supply dispatching to the monitoring personnel of the monitoring platform to try to pull the lines that may be faulty one by one. After pulling a line, see if the bus grounding telemetry signal returns If it is reset, then close the switch, the busbar grounding will act again, that is, it is determined that the line is grounded. Due to the large number of lines that need to be checked, this mode is time-consuming and labor-intensive, which makes the accident handling efficiency low and the safety risk is high.

With the advancement of technology, the current substation on-site protection measurement and control device can realize the automatic opening and closing function of the circuit breaker. The monitoring personnel can remotely control the grounding of each line through the monitoring platform to explore the soft pressure plate (realize the automatic opening and closing function of the circuit breaker) to complete the single Although the interval grounding search operation is much more convenient than the traditional method, it still needs to check the lines one by one until the grounding line is found, and the efficiency of accident handling is still low