Research Of MPPT Control Method On The Small PV Generation System

Fossil-fuels are used most widely which is basic material to social development.Traditional patterns of energy consumption have resulted in many problems,such as severe environmental pollution and the imminent danger of energy exhaustion.Solar energy resource is the most abundant renewable energy and clean energy.The development and use of solar energy resource has little impact on the environment,which can largely alleviate social energy crisis and pollution of the environment.The solar cells can convert solar energy into electricity via the photovoltaic effect.The output of photovoltaic battery is highly affected by the environment.The output of photovoltaic battery has obvious non-linear features.To improve the utilization efficiency of photovoltaic cells,the maximum power point tracking(MPPT)is needed.The thesis expatiate the research background and significance of photovoltaic power generation.This thesis analyses the theory and electrical characteristics of PV batteries.According to the principle of photovoltaic cells mathematical model is established.For photovoltaic power generation system,the configuration and principle of MPPT method were analyzed.The thesis introduces a variety of commonly used maximum power point tracking method.Different tracking methods of maximum power point tracking process are analyzed.In the control of MPPT,the strategy was designed to prevent false judgment with the changes of the environment.In this thesis,the working characteristic and principle of DC/DC converter are introduced.In this thesis,a duty cycle variable step size perturbation observation method is designed to solve the confliction of dynamic response and steady state stability and simplify the controller structure.In this paper,using S function to write out the maximum power point tracking control method simulation module,combined with the basic function of MATLAB/SIMULINK module,photovoltaic system simulation model is built.The duty ratio of variable step length of MPPT and traditional methods are compared.And the advantage of proposed MPPT method is obtained by simulation analysis.The simulation results show that the maximum power point tracking control method has good dynamic response and steady state stability.