计及死区故障的3/2接线变电站的Petri网故障诊断方法

A fault diagnosis method of 3/2 connection substation based on Petri nets with dead-zone fault taken into account

现有针对3/2接线系统的故障诊断方法较少考虑死区故障,在基于保护和断路器动作信息进行故障诊断时易造成误判。提出一种计及死区故障的3/2接线变电站的Petri网故障诊断方法,除了系统中母线、线路和变压器等元件,对死区位置也建立其加权模糊时序Petri网模型。针对3/2接线系统不同死区位置、不同类型故障的跳闸策略,利用保护动作信息和断路器辅助节点开合状态信息构造死区故障辨识逻辑。通过死区故障的逻辑辨识和保护及断路器的时序约束检查,对诊断模型的结构和参数进行修正。测试系统仿真算例和电网实际故障案例表明,该方法能够在保护和断路器不正确动作和警报信息不完整等复杂状态下识别真实故障元件,提高了诊断的准确度和容错性。

The existing fault diagnosis methods for 3/2 connection system take little account of dead-zone fault, which can easily lead to misdiagnosis based on the alarm information of protection and circuit breaker. A fault diagnosis method of 3/2 connection substation based on Petri nets is proposed with dead-zone fault taken into account. Temporal weighted fuzzy Petri net model is constructed for dead zone besides the bus, line, and transformer. According to the tripping strategies of different types of dead-zone faults in different positions, identification logic for dead-zone fault is proposed with information of protection action and circuit breaker＇s opening and closing state. Thus the structure and parameters of diagnosis model can be modified by identifying the dead-zone fault logic and checking the timing constraints of the protection and circuit breakers. Simulation results of testing system and actual fault cases of power grid show that this method can accurately identify the fault component in complicated condition of alarm information incompleteness and maloperation or rejection of protection and circuit breaker, which improves the accuracy and fault-tolerance of the diagnosis.