Research On Double Model MPPT Control On Improved Photovoltaic Generation System

Due to the problems of energy crisis and environmental pollution have become increasingly serious.Therefore, the development of new energy has become the main way to solve the world energy crisis and environmental pollution.During the new energy,Solar energy is inexhaustible,widespread and non-pollution,so the photovoltaic(PV) power generation is safe and reliable, easy to use.Today, the world photovoltaic technology with a wide range of applications in various fields has become more sophisticated.The following is mainly research contents.Firstly, the types and working principle of PV cells are introduced.PV battery equivalent circuit and mathematical modeling, which using Matlab / Simulink to built the simulation model of photovoltaic array, and the characteristics of the output characteristic curve of PV array under different parameters are analyzed.Secondly, the Boost chopper circuit as the DC/DC circuit is used and the maximum power point tracking(MPPT) control strategy is introduced. Based on the analysis of the advantages and disadvantages of the traditional control method and the principle of fuzzy control, a dual mode control method with combination of fuzzy control and PID control is established.In the process of MPPT control, the maximum power of the PV array output is quickly tracked by fuzzy control, and then using PID control to eliminate the oscillation of the maximum power point.Considering the difficulty to adjust the parameters of PID control,fuzzy control is introduced to the adjustment of PID control parameters to achieve online adjustment of PID control parameters,which reduce the energy loss and the influence of the external environment,further improve the tracking accuracy and conversion efficiency of PV array.Finally,the circuit topology and control strategy of common grid PV inverter is analyzed,which is a kind of research of H6 bridge inverter circuit with high efficiency and small leakage current combine with quasi-proportional resonant and PI control to control current of grid inverter.This method can effectively improve the system stability and anti-interference ability of harmonic.3k W PV power generator is used in the experiment, analyzing the parameters of the circuit, the hardware circuit and the program flow chart are designed.DSP-control chip can achieve the control of maximum power tracking and grid inverter.From the simulation and experimental results, the improved control method has better control effect and can meet the needs of the requirements of control.