Study On The Output Characteristics And MPPT Of PV System Under Complex Illumination

Solar energy as a clean green alternative energy, because inexhaustible, pollution and other advantages, has been developing rapidly in recent years. As one way of photovoltaic solar energy utilization, has become a major trend. Key technologies related to PV systems today run has matured, but there are still high cost, low efficiency, economy and poor, severely restricting its further promotion and application. Therefore, to further improve the efficiency of photovoltaic power generation around the system, reduce development costs, have become experts in the field of domestic and international PV research priorities.This paper focuses on improving the efficiency of PV systems, it investigates the output characteristics of PV arrays and maximum power point tracking (MPPT) under complex lighting conditions the main contents of this paper are as follows:(1) It introduces the basic principles of photovoltaic power generation, a photovoltaic cell simulation model is built using Matlab/Simulink. The output of the PV curves are analyzed through the simulation.(2) It investigates the output of the PV arrays under complex lighting conditions. Firstly, the partial shading problem of the photovoltaic array is analyzed; secondly, the output equations of both tandem and parallel PV arrays under complex lighting conditions are deduced bases on the output current and voltage. The output characteristic of the PV model under complex lighting conditions is established bases on it and the output characteristic curves are got at the same time. Finally, the characteristic of PV output curves and the local extreme points under shading conditions are analyzed, while the mobile cloud and output characteristics under different array structure of the PV array variation curve are studied. A theoretical foundation for PV array MPPT algorithm is provided by this paper.(3) This paper investigates one of the major ways of improving the efficiency of the photovoltaic system:the MPPT technology. It includes traditional MPPT algorithms and MPPT algorithms under complex lighting conditions. After introducing the principle of MPPT algorithm briefly, it builds Boost circuit for achieving MPPT algorithm using Matlab. This paper introduces three conventional MPPT control methods based on neural networks and multimodal MPPT technology, the maximum power point tracking control of PV systems is achieved using neural network and the validity of the method is verified using Matlab simulation software; finally, this paper compares the results with the conventional MPPT technology-disturbance observation method and shows the superiority of the new method.