Study Of Power Networks Fault Diagnosis Based On Improved Model And Binary Particle Swarm Optimization

With the expanding of the scale of power grid, more and more IEDs have been commissioned in power systems. Once there is a fault, large amount of alarm information will pour into the control center, so it is difficult for dispatchers to make a decision immediately. Therefore, it is necessary to develop a system with good veracity which can diagnose fault-section in powr networks for assisting dispatchers to judge rapidly and the research is very significant for shortening time of accident disposal, enhancing reliability of power supply and guaranteing safety and stability of power system.In this thesis, the features of fault information of distribution networks and transmission networks are analyzed, the problems of fault location in distribution networks and fault diagnosis in transmission networks are coverted into 0-1 itegral programming problem and the optimal model of transmission networks is improved, then the binary Paricle Swarm Optimization (PSO) is introduced for solving optimal model.Aiming at fault location in distribution networks, evaluation function is establishied based on topological structure of distribution networks and characteristic of fault information from FTU and optimized by binary PSO algorithm, then made a comparative analysis with Genetic Algorithm (GA). The simulation results show this method has good veracity in locating single fault or multiful faults or a little information form FTU is distorted, and its convergent velocity and performance are better than GA for solving fault location in distribution networks.Aiming at fault diagnosis in transmission networks, for quick fault diagnosis and integrative utilization of fault information, the multi-layer fault diagnosis system based on optimization-based method is established. The first layer identifies fault area depending on circuit breakers imformation, which can form doubtful fault-section set. Evaluation function based on imformation of circuit breakers and protective relays is improved in second-layer diagnosis and optimized by binary PSO algorithm, then made a comparative analysis with GA also. The simulation results indicate the method is useful for simple fault and complicatied fault with misstrip of protective relays and circuit breakers. Wave recording is considered in the third layer, fault-direction information is distilled by caculating wave recording and evaluation function including fault-direction information is formed based on the model of the second layer. Through a large sum of simulations, it indicates this method has good performance for complicated fault with losing of a little protective relays information.According to analyses and simulations, it indicates that the optimization-based fault diagnosis algorithm of distribution and transmission networks based on binary PSO has good adaptability.