消除变压器盲区故障的继电保护方法

A Relay Protection Method of Climinating the Blind Zone of the Transformer

由于差动保护和后备保护的局限性,变压器中、低侧断路器和电流互感器之间发生故障时保护可能发生拒动的情况,给变压器和电网运行带来严重后果。为此在原有运行继电保护设备的基础上考虑增加一种以中、低侧断路器位置为辅助判据,通过保护内部逻辑判据和更改相应的外部接线来消除此处故障的继电保护方法。根据理论判断和现场模拟,该方法满足运行要求,达到设计目的。

Due to the limitations of differential protection and back-up protection, when the fault occurs between the circuit breaker and the current transformer at the medium and low sides of the transformer, the protection can refuse to operate. It will lead the transformer and the electric network to serious consequences. For this, it should add a medium and low side circuit, breaker position as auxiliary criteria on the basis of the original relay protection. The relay protection method that eliminate this facult is through protecting in ternal logic criteria and changing corresponding external wircing. According to the theoretical judgemnet and field imitation, the method can meet operation requirements and attain the design objective.,