A regional differential protection device and protection method for responding to phase-to-phase faults in distribution network

Abstract

The invention discloses an area differential protection system and method reflecting an inter-phase fault of a power distribution network. The device is mounted in each bus, and an RS485 bus reads data information of each incoming / outgoing wire in the bus; different area protection devices communicate with each other via fibers; and the area differential protection device with most branch lines inthe bus serves as a main station. The method comprises that the area differential protection device with most branch lines in the bus is selected as the main station; real-timeline operation data collected by the area differential protection device in the line is exchanged mutually among different area differential protection devices; the area differential protector makes determination when the detected single-phase current abrupt change amount is higher than a setting value; fault information is sent when the minimal action differential current is greater than or equivalent to 0.7 time of the sum of a brake current and a load current; and the fault information is sent to the main station to construct a fault information matrix A. Thus, a fault of the power distribution network is detected and the inter-phase fault is isolated rapidly efficiently.

Description

technical field [0001] The invention belongs to the fault detection technology of power equipment, in particular to an area differential protection device and a protection method for a distribution network responding to phase-to-phase faults. Background technique [0002] At present, there are many branch lines of the distribution network, but not all of them are equipped with circuit breakers, and most of them exist in the form of load switches, which cannot be used to cut off the fault current. However, when distributed power is connected, circuit breakers are often used, and there are many cascaded switches. In order to achieve regional protection, it may be necessary to set a long delay, relying only on a single staged protection coordinated in time It no longer meets the requirements of fast and accurate fault removal of relay protection devices. In this case, the rapidity and regionality of protection are a pair of contradictions that are difficult to reconcile. With...

AI Technical Summary

Problems solved by technology

Protection systems and devices lack unified information integration and interconnection technical means, so that the cooperation between multi-terminal differential protection and distributed power supply protection is still unrealized.

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