Allocation Of Active Power Filter Based On The Isolated Niche Particle Swarm Optimization

With the depleting of the non-renewable energy,the rough and inefficient way of energy management and use has lagged behind the requirements of modern society.In order to improve the consuming capacity of distributed renewable energy,micro-grid technology has developed rapidly.The harmonic pollution in microgrid caused by nonlinear loads,grid-connected converters and harmonic penetration is serious increasingly.At present,the use of active power filter for harmonic pollution control is local governance mainly.The traditional decentralized configuration principle is no longer applicable to the multi-harmonic source power network.Therefore,it is necessary to study the centralized compensation technology of active power filter in microgrid.In this paper,firstly,the harmonic characteristics of the distributed power supply for photovoltaic and wind power generation in microgrid are analyzed,and the harmonic characteristics of the common nonlinear loads such as electric arc furnaces,TV sets,energy saving lamps and elevators are described.Combined with the engineering example,the power system simulation software ETAP is used to simulate the harmonic current of AC / DC hybrid microgrid and some conclusions are obtained about the propagation law of harmonic propagation.Based on the modeling of transmission line,transformer,linear load and harmonic source in the microgrid,the method of harmonic power flow calculation based on Newton-Raphson decoupling algorithm is designed and the algorithm flow chart is given.The basic idea,parameter meaning and algorithm flow of the basic particle swarm are introduced.The improved particle swarm optimization(PSO)is introduced briefly from three aspects: population structure,basic parameters and hybrid algorithm.In order to improve the disadvantage of standard PSO algorithm,the isolated niche particle swarm optimization is proposed,and the performance of the improved algorithm is tested by several standard test functions.A mathematical optimization model is established,which takes the minimum root mean square of the total voltage harmonic distortion rate as the objective function,and the total harmonic distortion rate of the node,the harmonic voltage of each node and the capacity of the device as the constraint conditions.The method of SAPF based on INPSO is introduced,including the particle coding,fitness function and configuration.The SIEMENS Benchmark 0.4kV is used to simplify the microgrid model to verify the optimal allocation method.The results show that the harmonic content of the microgrid is greatly reduced after the configuration of the SAPF,which is in accordance with the relevant standards.