The Research Of Grid Short-Circuit Fault Diagnosis Based On Probability Petri Net Model

Aiming at the deficiency of the current grid short-circuit fault diagnosis method, considering the combination explosion problem when Petri nets was used in fault diagnosis of power grids and traditional Petri nets cannot effectively deal with the uncertain information in power grid.Firstly, aiming at the shortcomings of the traditional Petri net, Making some improvements, forming a Petri nets model that combined with probability information, and on this basis, contraposing uncertain information in the grid, adopting a kind of probability inference rules that can effectively and accurately identify the fault components. The method can solve the diagnosis explosion blast occurs when traditional Petri net model used in a large power grid, and give the protection and corresponding circuit breaker a correct action probability value while the protection or circuit breaker in power grid may occurs malfunction or refusal-operation and SCADA system inaccurately monitors the fault information.Secondly, in power grid fault diagnosis, based on circuit breaker protection and correct action probability value directly form the initial marking 0M of probability Petri nets model for element and then can get the corresponding incidence matrix C. And according to the initial probability value of first layer in correlation matrix and from left to right, from top to bottom conducting the mathematical calculation to simulate the tolkien’s passing situation, which can accurately get the failure propagation paths and corresponding probability value, thus accomplishes the rapid diagnosis and localization of fault component. The method simplifies the complex process of traditional fault diagnosis and makes the efficiency and accuracy of fault diagnosis had evident improvement.Finally, the probability Petri net is used to model and analysis IEEE 118 bus standard experimental circuit, and then the feasibility and effectiveness for short-circuit fault diagnosis of the power grid are verified by experimental circuits.