Fault protection system for distribution system

Abstract

The present invention discloses a fault protection system for a distribution system. The system comprises a grounding-transformer protection device, a neutral point protection device, a transformer protection device for a station, a line protection device, a capacitor protection device, a low backup protection device, a high backup protection and a segment protection device which are connected with the A net and the B net of a station control layer of the distribution system and a synchronization time setting network, and each protection device interacts each operation state and the open and close state of the breaker connected with each protection device. Through network information interaction, the fault protection system for a distribution system allows the grounding-transformer protection device to timely know the position of the single-phase grounding fault, after the single-phase grounding fault happens, the grounding-transformer protection device does not need to wait for the motion time of other protection devices any longer and directly perform motion according to the itself delay, so that the protection motion time is reduced, the sensitivity is high, the rapid cutting of the single-phase grounding fault is realized as far as possible.

Description

technical field [0001] The invention relates to the technical field of power distribution fault processing, in particular to a fault protection system for power distribution systems. Background technique [0002] With the continuous expansion of the distribution network scale, how to ensure the timely detection and isolation of single-phase ground faults, and how to ensure the reliability of the power supply of the distribution network while ensuring the safety of people and equipment is a major problem. With the development of domestic distribution network construction and the extensive use of special cable lines in the distribution network, the capacitive current of the distribution system is also increasing. When a single-phase ground fault occurs, due to the large capacitive current, the arc cannot Self-extinguishing, especially when high-impedance grounding occurs, there is no way to quickly and accurately select the line to trip, resulting in the expansion of single-ph...

AI Technical Summary

Problems solved by technology

[0005] However, in the existing method, when a single-phase ground fault occurs in the line interval, the protection device on the line will control the corresponding circuit breaker to disconnect after the T1 time. If the single-phase ground fault still exists, after the T2 time, Then the protective device of the grounding transformer trips the upper-level circuit breaker; and when a single-phase ground fault occurs in the busbar or the grounding transformer bay, the protective device on the line will not operate, but the protective device of the grounding transformer still needs to wait for T1+T2 time. Can move

It can be seen that when a single-phase ground fault occurs in a non-line interval, the ground transformer protection device also operates after a long delay. The protection action time is long and the sensitivity is poor. The system brings great adverse effects

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