Research On Phase Photovoltaic Grid Operation Interface Modeling And Control Strategy

Energy shortage and environmental pollution has been worsening caused by the continuous development of society, the development of clean and renewable energy is imminent. Solar energy as a clean and green renewable energy, countries all over the world for its development and utilization of the constantly expanding scale. Photovoltaic power generation system is a nonlinear system, by the light intensity, temperature, and related control technology, and many other factors, and, in turn, these factors will affect the photovoltaic energy conversion and utilization, thus carries on the precise control research is very important. At present, usually take photovoltaic power supply through the inverter in the power grid, parallel operation for power conversion and power quality research and analysis to the whole system. This article mainly from the photovoltaic battery power conversion problem solving and grid-connection control strategy impact on system stability problem of these two aspects to study and analysis of the photovoltaic grid system.This paper describes the research current situation and trend of development of solar photovoltaic power generation, the classification of the photovoltaic power generation system, the classification of photovoltaic grid system and photovoltaic grid inverter, mathematical modeling and engineering application modeling of photovoltaic cell, simulation resulting photovoltaic cell output power with the relationship between light intensity and temperature by MATLAB/SIMULINK, while Boost booster circuit for circuit analysis and parameter selection and introduces the traditional technology of maximum power point tracking(MPPT) on the basis of combining the open circuit voltage disturbance observation method and variable step length, discusses a kind of improved MPPT control method, set up in MATLAB/SIMULINK simulation model, simulation validate the control can achieve good fast track, reduce the running cycle of the system, and the sensitive to the implementation of the variable step tracking, make the system working condition to achieve maximum power point. Paper type to choose LCL filter for grid harmonic suppression problem as the research object of mathematical modeling, this paper expounds the mechanism of high frequency resonance system and commonly used method of harmonic suppression and the LCL filter parameter selection. Paper introduces the proportion of quasi resonant characteristics of the control and repetitive control, to further study the proportion of quasi resonant repeat grid based on the double closed-loop current control strategy, establish the double closed loop current, quasi resonant repeat grid control theory model, is presented to ensure stability of the system controller design, set up in MATLAB/SIMULINK simulation model, simulation verify that the control strategy can make the system has good steady-state performance, the high frequency harmonic suppression ability and anti-interference ability.