Research On Global MPPT Control For PV Array Based On Promoted PSO Algorithm

With energy crisis and pollution becoming more and more serious,the clean and renewable energy represented by solar energy attracts much attention.Solar energy is considered to be the most potential energy in future because it’s clean,inexhaustible,evenly distributed,and does not lead to energy monopoly,etc.This paper analyzes the background of solar photovoltaic power generation,introduces its development prospect,and elaborates the issues it faces.Among them,the efficiency is one of the core issues.However,maximum power point tracking(MPPT)technology is one of the important means to improve efficiency.The Matlab/Simulink two-diode simulation model of photovoltaic cell is built in this paper.And the output characteristics curves are obtained by simulating when photovoltaic(PV)array is under uniform illumination and partially shaded conditions.Under partially shaded conditions conventional MPPT methods will fail,because power-voltage characteristic curve has multiple local maximum.This paper proposes a promoted particle swarm optimization(PSO)algorithm after studying the PSO algorithm applied in solving multiple MPPT.In the promoted PSO algorithm,before updating the particles,they are ranked based on individual optimal positions firstly,and then updated according with this order.In the velocity equation,the current global optimization result is used rather than the global optimization result before this generation which is used in conventional PSO algorithm so that the maximum power point can be found more quickly to improve the rate of tracking.Moreover,the standard deviation of all particles which reflects the level of gather and the distance between particles and current global optimization result which reflects the level of excursion are drawn into the velocity threshold value to restrict the maximum change of every particle separately and self-adaptively.Finally,the Matlab/Simulink MPPT simulation system based on Boost circuit and experimental system are designed and built.Then the simulation and experiment results indicate that the promoted PSO algorithm can fast and accurately track the global maximum under partially shaded conditions,and can improve the efficiency.