Maximum Power Point Tracking Of PV System Under Partially Shaded Condition

With the extensive application of photovoltaic distributed generation, photovoltaic power generation system in which the environment has become more complex, especially small and medium-sized PV system installed in the built-up area, the partial shadow problem is difficult to avoid. Cloud cover, dust, trees or building block make photovoltaic cells surface illumination uneven, resulting in changes in the output characteristics of photovoltaic cells. Because a number of extreme points appear on the output voltage of the power curve, maximum power point tracking tradition (Maximum Power Point Tracking, MPPT) algorithms may be false positives. Therefore, an effective control method to solve the maximum power point under partial shadow tracking photovoltaic systems need to be study.This thesis analyzes the working principle of photovoltaic cells as well as the physical characteristics and the problem of hot spot effect, using Matlab/Simulink to establish the photovoltaic array simulation model considering partial shading. Then simulation analysis of the principle and distribution of producing multi-peaks voltage power curve, and putting forward the optimization design of photovoltaic array, which lays a theoretical foundation for the research of MPPT method with consideration of partial shadingPV array maximum power point tracking control is a key technology of photovoltaic power generation system. By analyzing the advantages and disadvantages of particle swarm optimization algorithm is applied MPPT control, this paper proposes a reference to quantum particle swarm algorithm MPPT control of photovoltaic systems. Quantum particle swarm algorithm has high convergence precision, not easy to fall into local optimum, etc., and the program is easier to achieve than particle swarm. This paper describes the principles of quantum particle swarm algorithm, the basic characteristics, the design process and used in MPPT control theory.To verify the correctness and superiority based on quantum particle swarm MPPT control, in this paper, a simulation model of photovoltaic systems is build by using Matlab/Simulink. Through simulation analysis with the traditional MPPT method, PSO algorithm and QPSO algorithm, the paper verifies the feasibility and stability based on QPSO algorithm in MPPT control applications, improving the PV array output efficiency under partial shading.