School of Electrical Engineering and Electronic Information, Xihua University
Fast and accurate diagnosis of fault components is one of the important preconditions to realize on-line regulation and operation of power grid. Because of its clear modeling and careful logic, the fault diagnosis method of power grid based on Petri net has been widely concerned by many researchers. However, most of the current methods consider the digital information, and pay less attention to the analogue information, and the analogue information has more advantages than the digital information in accuracy, fault tolerance and so on. Based on this, a fault diagnosis method of power grid based on Petri net considering the analogue one and the digital part is proposed. Firstly, the fault current of the components is extracted by Hilbert-Huang transform, and the fault probability of the components is obtained through fuzzy logic analysis and fuzzy logic Petri net reasoning. Secondly, based on the analysis of the digital information, the Petri net model of the components is established, and the constraint check and mining analysis of the fault sequence information are carried out, and the fault probability is obtained by fuzzy reasoning calculation. Finally, D-S evidence theory is used to fuse the fault probability level to obtain the final failure probability of components. Several fault cases of the New England 10 machine 39 bus system are tested. The results show that the method can quickly diagnose fault components, improve the limitations of single fault source and single diagnosis method, and effectively improve the accuracy and fault tolerance of fault diagnosis.