Research On Photovoltaic MPPT And Fault Location Of Distribution Network Based On An Improved Sine Cosine Algorithm

With the increasing consumption of fossil energy and the aggravation of environmental pollution,the development and utilization of new energy in human society has greatly increased.Photovoltaic power generation,as a kind of distributed power generation,has more and more proportion in the power grid because of its flexible,clean and pollution-free characteristics.The performance of photovoltaic power generation system mainly depends on the output power of the photovoltaic cells,and the output characteristics of the photovoltaic cells under partial shading show multimodal characteristics,and the traditional maximum power point tracking method will fail.At the same time,a large number of distributed generation is connected to the distribution network,which make the distribution network change from one-way power flow to two-way power flow and has higher requirements for the fault location method of the distribution network.In this paper,the improved sine cosine algorithm(SCA)is used to solve the problem of the maximum power point tracking under partial shading and the fault section location of distribution network with distributed generation.Firstly,the cosine algorithm is improved by introducing nonlinear parameters,self-learning strategy and stagnation disturbance strategy.The convergence of the improved cosine algorithm is proved,and its effectiveness and superiority in global optimization are verified by several groups of test functions.Secondly,in the aspect of photovoltaic maximum power point tracking under partial shading,the principle and engineering mathematical model of photovoltaic cell and the output characteristics of photovoltaic array are introduced.In the later stage of the algorithm,the iteration termination strategy and algorithm restart condition are added,which effectively improves the speed and accuracy of MPPT tracking,and enables the system to achieve MPPT under dynamic conditions.By building simulation model in MATLAB,the feasibility of the algorithm is verified.By building Matlab / Simulink simulation model and speedgoat hardware in the loop experiment platform,the feasibility of the algorithm is verified.Finally,in the distribution network with distributed generation,the positive direction of the network and the coding mode of each switch are redefined.The binary sine cosine algorithm is used to locate the fault zone and analyze the fault tolerance of ieee-33 node distribution network with distributed generation.Compared with the binary particle swarm optimization and genetic algorithm,the results show that the improved binary sine cosine algorithm has obvious advantages in convergence speed and positioning time.