Low Power Solar Photovoltaic (pv) Grid Power Generation System Research

With the development of economy and the progress of the society, great amount of energy has been demanded, which also raises the problem of energy crisis and serious pollution. How to protect the ecological environment when we make the exploitation and utilization of energy is a global problem. Solar energy is a kind of ideal renewable energy because its wide distribution and abundant resources can effectively balance contradiction between the energy utilization and the environmental protection.Solar photovoltaic power generation is an important use form of solar energy, which can be divided into independent power generation system and grid generation system. Grid system will be the mainstream in solar photovoltaic power generation market. Based on theoretical foundation of solar photovoltaic grid power system, this paper makes analysis and research on all main parts of the system. Building on the platform of "micro-grid simulation experiment system", photovoltaic grid power system structure and control algorithm have undergone the test to realize the function of the public power generation.First of all, the paper analyses and studies photovoltaic grid inverter topological structure, and makes the design of double levels of structure with the isolated transformer power frequency. With coordinate transformation as the theoretical basis, a mathematic model of photovoltaic grid inverter back DC/AC converters is set up and analyzed, and the DC/AC converters outer ring, the voltage electric circuit and the double loop control algorithm, and SVPWM modulation mode and the control strategy to effective complete unit power factor grid control are discussed. By MATLAB/SIMULINK software simulation model is established, and the experimental results verify the correctness of the control algorithm.Then, the article analyzes the characteristics of solar energy photovoltaic cells, and the importance of maximum power tracking (MPPT) for solar photovoltaic power generation system. With boost circuit as a photovoltaic grid inverter of front DC/DC converter, the paper analyzes its working principle and the realization method of the most power tracing (MPPT), compares several MPPT algorithm. The author chooses improved perturbation of observation as MPPT control algorithm, and gives the specific work process, use MATLAB/SIMULINK software as simulation model, and verify the correctness of the control algorithm by the experiment.Finally, through "the power grid simulation experiment system" project,2KW prototype design and production are completed, including electrical structure design and control system design and the experiment and debugging for the overall unit, realizing control targets of grid generation for public power.