时间约束的改进分层模糊Petri网的配电网故障诊断方法

Improved hierarchical fuzzy Petri net with temporal constraints for distribution network fault diagnosis

配电网发生故障后,迅速利用大量的告警信息判别出故障元件,能为调度中心的工作人员提供重要的决策支持。针对现有Petri网的故障诊断方法未应用在配电网中的问题,提出了一种时间约束的改进分层模糊Petri网的配电网故障诊断方法。对配电网中的可疑故障元件建立改进的分层模糊Petri网模型,能够适应网络拓扑结构的变换,利用获得的报警信息通过反向和正向时序推理对保护和断路器进行时序检查,对不满足时间约束的库所进行置信度修正。给出了改进分层模糊Petri网模型的推理流程及矩阵推理算法,在矩阵推理过程中引入高斯函数修正概率,使概率始终保持在0~1,最终得到故障元件的置信概率及其时间点约束。通过对配电网系统算例的比较、分析,验证了所提方法的正确性和合理性,能够有效地诊断出配电网的故障元件。

After distribution network failure, a large number of alarm information will be generated. These information can be used to identify the faulty components quickly, and hence providing important decision support for dispatching center staff. Since the existing fault diagnosis methods of Petri nets are not applied in the distribution network, an improved hierarchical fuzzy Petri nets fault diagnosis method based on temporal constraints is proposed. An improved hierarchical fuzzy Petri net model for suspected fault component in distribution network is established, which can adapt to the change of network topology. The obtained alarm information is used to check the sequence of protection and circuit breakers by reverse and forward temporal reasoning, and the confidence of the transitions that does not meet the time constraints is corrected. The reasoning process and the matrix reasoning algorithm of the improved hierarchical fuzzy Petri net model are given. In the process of matrix reasoning, the modified probability of Gauss function is introduced to keep the probability at 0~1. Finally, the confidence probability of the fault components and its temporal point constraint are obtained. Through the comparison and analysis of the distribution network system examples, the correctness and rationality of the proposed method are verified, and the fault components of the distribution network can be effectively diagnosed.