Design Of Photovoltaic Array Power Regulator And Realization Of Multi-peak MPPT Algorithm

With the gradual consumption of traditional energy and the aggravation of environmental pollution,the development of green energy has gradually become a consensus.Solar energy as the first choice of green energy in the future,has the advantages of economy,environmental protection and sustainability.Photovoltaic power generation is one of the main applications of solar energy.Its core hardware circuit includes photovoltaic array and array power regulator.Photovoltaic array is the power source of photovoltaic system,and its output has nonlinear characteristics.The array power regulator is the controller of the photovoltaic system and can adjust the photovoltaic array to work in either the stabilized voltage mode or the maximum power tracking(MPPT)mode.In general,the traditional MPPT algorithm can make the photovoltaic array work at the maximum power point to maximize the power utilization of the photovoltaic array.However,the P-U characteristic curve of the photovoltaic array presents multi-peak characteristics when the photovoltaic array is particially shaded,and the traditional MPPT algorithm may fail.In this case,the multi-peak MPPT algorithm is required to realize the global maximum power point tracking.When multiple photovoltaic modules are connected in parallel to supply power to the load at the same time,necessary current-sharing measures are needed to ensure the power balance of each module and improve the system stability.This paper mainly studies the simulation and realization of photovoltaic array power regulator.The main work contents are as follows:(1)The common models of photovoltaic cells are deduced and analyzed,and the influence of working conditions on the output characteristics of photovoltaic arrays is also studied.The working process of common dcdc converter is analyzed and the parameter relation of buck-boost topology is deduced.(2)The power regulator model is builded based on Matlab/Simulink platform,and its voltage stabilization mode,MPPT mode,multi-peak MPPT algorithm and multi-module parallel current sharing function is successively realized.Based on PID control algorithm,the simulation and analysis of the stabilized voltage mode is realized;A variety of MPPT algorithms are used to realize the maximum power tracking simulation,and the comparative analysis is carried out.The perturb,observe and check(POC)algorithm is used to realize the multi-peak maximum power tracking simulation.Based on droop control,the current sharing simulation of photovoltaic array multi-module parallel power supply is realized.(3)An array power regulator with a maximum power of 300 W is designed.Based on the hardware circuit and FPGA control,the test and experimental verification of the power regulator’s voltage stabilization mode,MPPT mode and multi-module parallel current sharing are completed in turn.In this paper,by analyzing the working principle of photovoltaic cells,an engineering model of photovoltaic cells is established to study the output characteristics of photovoltaic cells,and an array power regulator model is built.The simulation verifies the power regulator’s voltage stabilization mode,MPPT mode,multi-peak MPPT mode and multimodule parallel current sharing function.An array power regulator with a maximum power of 300 W is designed based on the simulation model,and the experimental verification of voltage stabilization mode,MPPT mode and multi-module parallel current sharing is completed.The experimental results show that the designed power regulator can achieve voltage stabilization mode and MPPT mode,it also shows that multi-module parallel current sharing is effective.