Solar Photovoltaic Power Generation Systems Interconnection Control Technology Research

As the world’s fossil fuels are depleted and the environmental pollution isincreasingly serious,development and using various renewable energy becomesthe primary task of human now.Solar energy is widely distributed、safe andclean.It is renewable and becomes the international ideal alternativeenergy.Therefore,the photovoltaic power generation system receives more andmore high attention of each country government.Grid inverter is an important device.It can make the electric powergeneration system to the grid.The control technology of the grid-connectedinverter is a hot topic of current research.In this paper,the grid-connected inverter is the object of study.It researchesthe topology of the grid-connected inverter and the technology of the phaselocked loop.It designs the hardware platform of the single phase photovoltaicinverter system.To ensure the photovoltaic system can connect the grid,thefrequency and the phase of the grid-connected inverter current must be the samewith grid voltage’s.To the end,on the basis of analysis the working principle andthe mathematical model of the phase locked loop’s three main modules.It studiesthe software phase locked loop technology,and analyzes the genlock strategy ofthe single phase grid-connected inverter based on the d-q transformation.Itanalyzes pairs Park transformation and proposes an improved software phaselocked loop based on the coordinate transformation.It uses the improvedsoftware phase locked loop in the control circuit of the photovoltaic powergeneration system.Finally,it verifies the control capabilities of the improvedsoftware phase locked loop by matlab simulation.