Research On Multi Peak MPPT Control Of Photovoltaic System Under Partial Shadow

Photovoltaic power generation is currently widely used in renewable clean energy.One of the important technologies of photovoltaic power generation systems is Maximum Power Point Tracking(MPPT).However,in practical applications,the photovoltaic array is prone to local occlusion.At this point,there will be multiple extreme points on the PV battery power output curve,so the classic maximum power point tracking method will be difficult to avoid and only one local maximum can be searched.Therefore,it is necessary to study the maximum power point tracking algorithm of solar cell power generation components under partial shading.The paper introduces the composition,classification and application of photovoltaic power generation system,and analyzes the power generation principle and output characteristics of solar cell modules.The causes and solutions of the hot spot effect are expounded.The causes of multiple peaks in the P-V curve under local shading are analyzed.The physical model and mathematical model of the solar cell are also studied.Several classic MPPT algorithms and multi-peak MPPT algorithms are summarized,and the advantages and disadvantages of these methods are summarized.The paper introduces the principle and design flow of the basic particle swarm optimization(PSO)algorithm.For its insufficiency to trace the global optimal value,the optimization speed is slow,and the convergence accuracy is not high,this paper adopts an improved back-off PSO algorithm.Then,several function test analysis is given for the performance of the proposed algorithm.The test results show that the back-off particle swarm algorithm is better than the basic PSO algorithm in terms of optimization accuracy and convergence speed.The advantage of the back-off PSO algorithm in multi-peak optimization is applicable to the MPPT control under partial shading.Then the whole system model of the back-off PSO algorithm MPPT control module is built in Simulink.The obtained result analysis proves that The algorithm has good fastness and accuracy for the tracking of multi-peak MPP,thus completing the global optimization of MPPT in the local shadow of photovoltaic cells.Finally,the simulation model of each module in the control system is built,and the whole control system is simulated.The simulation results show that the algorithm can track the maximum power point quickly andaccurately,and the output power of the system is always around the maximum power point voltage,which proves the feasibility and effectiveness of the algorithm,thus improving the local shading.The output efficiency of a solar photovoltaic system.