基于事件起点的层次化时序Petri网及其电网故障诊断方法

电网发生故障后利用大量告警信息快速准确地识别故障元件是保障可靠供电和电网安全稳定运行的首要任务。为适应电网运行调控需求,提出一种基于事件起点的层次化加权模糊时序Petri网故障诊断方法。在完善母线和线路的层次化加权模糊时序Petri网模型的基础上,以故障发生时刻为事件起点,确立各初始库所的时序属性,并通过逆向和正向时序推理对保护和断路器动作信息进行时序约束检查和置信度修正。IEEE 39节点系统仿真算例和电网实际故障算例表明所提方法能够在保护和断路器误动/拒动、告警信息缺失/错误等复杂状态下识别真实故障元件,提高了故障诊断的准确度和容错性。此外所提方法还可以得到设备故障的时间点约束,有利于进一步分析故障原因和故障事态发展。通过与现有应用时序信息的故障诊断方法相比,所提方法时序推理过程简明清晰,对网络拓扑的变化适应性强,运算速度快,满足在线诊断需求。

Hierarchical temporal Petri net based on event-starting point and its fault diagnosis method of power grid

The most important task to ensure reliable power supply and safe and stable operation of the power grid is the quick and accurate identification of the fault element based on mass warning information. A fault diagnosis method of hierarchical weighted fuzzy Petri net based on event-starting point is proposed to meet the needs of power grid operation and regulation. Based on the improvement of the hierarchical temporal weighted fuzzy Petri net of bus and line, the temporal attribute of each initial library is determined by taking the fault occurrence time as the event-star-ting point. The temporal constraint of the protection and circuit breaker operation is checked and their credibility is modified according to reverse and positive timing reasoning. The simulative results of IEEE 39-bus system and actual failure cases of a power grid show that the proposed method can identify the fault element under complicated conditions such as mal-operation or rejection of protection and circuit breaker and incompleteness or error of alarm information, and improve the accuracy and fault-tolerance of fault diagnosis. In addition, the proposed method can also get the time constraint of the fault element to further analyze the causes and development of the fault. Compared with the existing fault diagnosis methods based on temporal information, the proposed method has a simple and clear temporal reasoning process, strong adaptability to the change of network topology and rapid calculation speed, and meets the needs of online fault diagnosis.