一起断路器防跳回路异常分析及改造

Analysis and reform of an abnormal phenomenon on breaker anti-jumping circuit

在断路器无油化改造后的现场试验中发现一起35kVSF6断路器防跳动作不正确事故。经分析该断路器二次接线图,并现场试验,发现为断路器防跳回路中存在异常,防跳继电器接在储能触点后面,造成防跳继电器在断路器储能阶段无法正常起动并自保持,从而使防跳保护失去了应有的保护作用。提出并实现了该断路器防跳回路改造方案,改造后进行了多项防跳试验,证明防跳保护动作正确可靠,消除了事故隐患。

An incorrect action of anti-jumping protection of 35 kV SF6 breaker was founded on field tests after the oil-free reform of breakers.A nalysis of the breaker secondary circuit diagrams and field experiments were carried out and an abnormal phenomenon was founded in the breaker anti-jumping circuit that the anti-jumping relay was connectted after the energy storage contact.The anti-jumping protection lost its function because the anti-jumping relay could not start and self-hold in the energy storage process of breaker.A reform scheme of the breaker anti-jumping circuit was put forward and implemented.After the reform,some experiments proved the correct reaction of the anti-jumping protection and the hidden cause of accidents was eliminated.