Research Of Photovoltaic Grid-connected Inverter And Output Control

With the worsening of the entire Earth’s energy and environmental conditions, photovoltaic power generation has been an unprecedented development. Large-scale utilization of solar energy will become the trend; grid-connected PV will become the main technical means of scale use solar energy.PV grid-connected inverter is key equipment to ensure the normal power generation of photovoltaic power plants connected to the grid and provide the electricity of meet the requirements. How to ensure the high quality and high efficiency of output power of grid-connected inverter, security and stability of connected to the grid, has been a theme of the photovoltaic grid-connected technology research.First, a simulation model of the photovoltaic array is builded, analyze the electrical characteristics of the PV array. Based on comprehensive comparison the common maximum power point tracking algorithm, for poor startup characteristics of conventional tracking algorithm proposed CVT method combined with conductivity tracking algorithm to improve the startup characteristics, by simulation verify algorithm improves the startup characteristics.Secondly, the advantages and disadvantages of method that more application to track grid-connected inverter current, used the space-vector tracing, detailed analysisthe the space vector PWM, optimized the space vector PWM method,through MATLAB simulation to verify algorithm can be fast, reliable, high-precision tracking inverter output current..Finally, Combine the main circuit characteristics of the PV grid-connected inverter and the active power filter device, based on instantaneous reactive power theory detect harmonic. Expand the APF function of grid-connected PV systems, achieve power system harmonics control and reactive power compensate, and given the overall design of this grid systems.