Research On Active Power Control Of Photovoltaic Power Generation System

As one of the most promising green renewable energy,solar photovoltaic power generation has been caused larger attention and developed rapidly in recent years.But it still has some shortcomings,such as high cost,low efficiency of energy conversion,poor power supply stability.The maximum power point tracking could improve energy conversion,so as to achieve the purpose of the full use of solar energy.Meanwhile,Because of the electrical energy can not be large storaged,the constant power point tracking could improve the stability of power supply in case of overloading.This paper analyzes several common methods' principle and the advantages and disadvantages of maximum power point tracking.On this basis,an improved variational step incremental conductance MPPT control method was proposed.The method can more accurately respond dynamic property of photovoltaic array,and could more accurately and steadily tracks MPP than other methods.Besides,the paper presents the importance of constant power control in photovoltaic power generation system.A simple constant power tracking method is presented,the method is simple in principle,easy implementation and has considerable application value.In addition,the paper analyzes work principle of DC/DC conversion circuit and design of active power controller.Finally,the mode of PV system with power controller is builted in Matlab/Simulink.it is simulated with improved variational step incremental conductance MPPT control method and constant power tracking method.Simulation results verify the effectivity of the proposed method.