Relay protection and failure location system for power distribution network

Abstract

The invention relates to a system used in the area of electrical power to locate fault rapidly. The system is composed of two parts i.e. multi measuring and executing units as well as communication channels to connect the said units. The measuring and executing units consist of current transformer, polarity detecting and comparing relay, first communication interface unit, second communication interface unit and circuit breaker. The communication channels consists of protecting channel and the channel utilized to locate fault on whole network. Whether the fault of equipment happens or not is judged by detecting and comparing the similarities and differences of polarity of electrical current fault component which has passed through the protected switch gear. The communicating means is used to connect all relays that protect the same equipment, it realizes relay protection for all distributing line, distributing bus line and distribution transformer. Personal staffs are able to find out and locate the fault location since this information of current polarity has been passed to dispatching center by communication means. The system is independent of particular configuration of distribution network and does not utilize information of voltage fault. The configuration of the system is simple and easy to realize.

Description

technical field [0001] The invention belongs to the field of power systems, in particular to relay protection and fault location technology for distribution networks. Background technique [0002] The distribution network is composed of many electrical devices, and it is inevitable that these electrical devices fail during operation. After a fault occurs, it is the fundamental task of relay protection to quickly detect the faulty equipment and act on the tripping of the circuit breaker to remove the faulty device; at the same time, to accurately provide the location of the fault so that the staff can repair and restore the faulty device. [0003] Relay protection operates according to fault information such as changes in current and voltage after a fault. At present, the relay protection of distribution lines and distribution transformers mainly adopts "current protection based on single-ended fault information"; the busbar protection adopts differential protection. Curren...

AI Technical Summary

Problems solved by technology

[0007] The carrier current phase differential protection of the high-voltage power grid is used, but it needs to exchange the current phases at both ends of the protected equipment. However, the distribution network is a single-ended power supply radiation network. After a fault, the current after the fault point disappears or decreases, and generally does not change direction. , causing the protection to fail

[0008] Obviously, in order to solve the problem of fast relay protection of distribution network and fault location of the whole network, it is impossible to use the current method

Images