Interlocking method of switches in three-half connection mode based on circuit breaker auxiliary protection

Abstract

The invention relates to a middle switch interlocking method in a three-seconds wiring mode based on breaker auxiliary protection. The middle switch interlocking method is characterized by comprising the following steps that a Q1 breaker auxiliary protection screen collects the analog quantities and position signals of a phase A, a phase B and a phase C, A-phase current-free state information, A-phase skipping state information, B-phase current-free state information, B-phase skipping state information, C-phase current-free state information and C-phase skipping state information are specially detected, and the detected specific states are expressed through logic 1 and logic 0. According to the technical scheme, the novel middle switch interlocking method is adopted, the breaker auxiliary protection device is used for assistance, interlocking logic judgment is carried out through switching value and analog quantity information collected by the breaker auxiliary protection device, and the method is simple and reliable in logic, convenient to implement and especially suitable for running convertor stations and large power stations.

Description

technical field [0001] The invention relates to a method for interlocking switches in a three-half connection mode based on auxiliary protection of circuit breakers. Background technique [0002] According to the requirements of the power system for the interlock control of the "middle switch" in the AC field of the converter station under special operating conditions, regardless of the rectifier side and the inverter side, if the switches on both sides of the string with the converter transformer are disconnected, the converter transformer In the case of direct connection with filter or AC line, the corresponding single pole of DC should be blocked immediately, and if the line is directly with filter, the middle switch should be disconnected. [0003] At present, this logic is implemented in the 330kV AC station control system, and there are mainly the following problems. 1. When the side switch of any interval busbar is overhauled, Q2, Q3 will run with line and filter ban...

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Problems solved by technology

2. When a bus fault occurs and the bus protection action trips the side switch, if a line fault occurs again at this time, the line protection will be single-jumped and heavy, which will cause an impact on the filter or converter. The existing middle switch There is a dead zone in the chain logic

After such a collection, analysis, and execution are completed, the action delay is increased. At the same time, because the signal travels through the field bus, there may be risks such as data congestion and bit errors. The action delay is further increased, and there is also the risk of refusal to move.

In addition, the intermediate switch chain logic implemented in the 330kV AC station control system only uses the position of the auxiliary contact of the circuit breaker or isolating switch for logical judgment. The secondary cable circuit in a strong electric field is very vulnerable to external interference. According to the judgment, there is a risk of misoperation

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