Synchronizing checking relay and angle locking method of synchronizing checking relay

Abstract

The invention discloses a synchronizing checking relay and an angle locking method of the synchronizing checking relay. The angle locking method comprises the following steps that firstly, output voltage us and ug of a system side power supply and a generator power supply are collected, and then, us and ug are respectively led into respective effective value converters after transformer isolation voltage reduction is carried out, and in addition, effective values Us and Ug are obtained; meanwhile, positive ends of us and ug subjected to isolation voltage reduction are respectively connected with positive and negative input ends of the other effective value converter, and the effective value Delta U is output after Delta u is obtained; and then, Us, Ug and Delta U are respectively led into a single chip microcomputer for carrying out A / D (analog to digital) conversion, in addition, the cosine law is utilized for solving Delta phi, finally, the Delta phi is compared with the preset locking angle, in addition, corresponding locking signals are output, the control precision is high, and the problem of frequent action of the locking output can be effectively solved.

Description

technical field [0001] The invention belongs to the professional field of power system automation, in particular to a synchronous inspection relay and an angle blocking method thereof. Background technique [0002] In the power system, the device that realizes the phase angle blocking when the circuit breaker is closed is called "synchronization check relay". The currently widely used synchronous inspection relay adopts the principle of electromagnetic and mechanical combination, and its locking angle accuracy is extremely low. At the same time, it is based on the fact that the effective values ​​of us and ug corresponding to the power supplies on both sides of the circuit breaker are equal, and the operating point is required to be at Near the specified value, even the wrong locking angle will be obtained in severe cases. In addition, when the locking angle is in the boundary condition, frequent actions of the locking output cannot be avoided, which will bring great harm t...

AI Technical Summary

Problems solved by technology

The currently widely used synchronous inspection relay adopts the principle of electromagnetic and mechanical combination, and its locking angle accuracy is extremely low. At the same time, it is based on the fact that the effective values ​​of us and ug corresponding to the power supplies on both sides of the circuit breaker are equal, and the operating point is required to be at Near the specified value, even the wrong locking angle can be obtained in severe cases

In addition, when the blocking angle is in the boundary condition, it is impossible to avoid the frequent action of the blocking output, which will bring great harm to the subsequent circuit operation.

In addition, due to mechanical characteristics, the output contacts are highly prone to seizure

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