基于分层模糊Petri网的电网故障综合诊断方法

为降低Petri网的规模,提高诊断的准确性和适应性,研究了一种用于电网故障综合诊断的分层、多子网模糊Petri网模型。考虑了主保护、近后备保护及远后备保护的不同作用,对各保护子网中变迁到终止库所的输出弧赋予不同的权值,修正了变迁的输出概率高斯求取函数。提出先建元件的各保护子网与线路单侧诊断子网、再建综合诊断子网的分层建模方法。该方法可根据电网拓扑变化对模型进行一定的自适应调整。给出了基于矩阵运算的推理过程。针对一个典型电网做了多组案例测试,实验结果验证了该模糊Petri网的有效性,在信息不完备情况下仍能给出正确的诊断结果。

A Method of Synthetical Fault Diagnosis for Power System Based on Fuzzy Hierarchical Petri Net

To minify the scale of Petri net and improve both accuracy and adaptability of power system fault diagnosis,a model of fuzzy hierarchical Petri net with multi subnets is proposed,in which different effects of main protection,local backup protection and remote backup protection are considered,and different weights are assigned to output arcs transited to termination places in protection subnets,and then the Gaussian function to solve output probabilities of the transition is modified.A hierarchical modeling approach is put forward,i.e.,the component protection subnets should be constructed at first and then the synthetical diagnosis subnets are established.This modeling approach can perform adaptive adjustment of the model according to the variation of network topology.The reasoning process based on matrix operations is given.The effectiveness of the proposed fuzzy hierarchical Petri net is verified by results of multi groups of test cases,and test results show that correct fault diagnosis results can be obtained under incomplete information or variation of network topology.