Judging method of double-bus bus-coupled running mode

Abstract

The invention discloses a judging method of a bus-coupled or segmented running mode in bus protection, which is characterized by comprising the following steps: (1) at the time of no fault, changing a bus-coupled CT from a non-current state into a current state, and under the condition that the running mode of bus-coupling is judged to be in a separated state, respectively adding the current of the bus-coupling into two buses to calculate difference currents; comparing an obtained calculating result with a calculating result when the running mode of the bus-coupling is judged to be in the separated state, and using the variation trend of the difference current for judging; (2) at the time of a fault, changing the bus-coupled CT from the non-current state into the current state, and under the condition that the running mode of the bus-coupling is judged to be in the separated state, turning off a differential outlet trip for a short period of time; and carrying out reasonable logical judgment through the changes of an SHJ node and a TWJ node of the bus-coupling and the differential condition action. The invention has high judge accuracy and cannot make an erroneous judgment on the mistake current or abnormal conditions of a bus-coupled current collection channel. An effective valve and a sampling value are adopted to carry out a compound judgment so as to make a complementation on judge accuracy and judge speed.

Description

technical field [0001] The invention relates to a method for judging the operation mode of a bus tie of double buses, which belongs to the field of electrical technology. Background technique [0002] The judgment of whether the bus tie current participates in the differential calculation directly affects the selectivity of the bus protection. When a dead zone fault occurs during hot standby, it is hoped that the bus tie current will not be included in the differential, so as not to expand the scope of the accident; It is hoped that the current of the bus coupler will be included in the small difference to prevent the misoperation of the running bus; this is a pair of contradictions, the bus coupler position node does not have real-time performance, and at the same time, it must be considered that there is a certain degree of redundancy in the case of an error in the external position node, increasing How to solve this contradiction well is the problem that needs to be studi...

AI Technical Summary

Problems solved by technology

[0007] 4) When the charging is on the faulty bus, if the charging locking differential is not adopted, the live bus will trip by mistake; if the charging locking differential is used, if the operating bus fails during the charging process, it will cause a delay of 300ms to operate, which will affect the system The potential safety hazard is still relatively large. For microcomputer protection, there is no need to adopt a locking method at all.

Images