Design And Research On Dual Closed Loop Control System Of Grid-conneeted Photovoltaie Inverter Based On DSP

With conventional energy is on the decrease, many countries focus on the researchand application of new energy technology. Photovoltaic inverter system as the typicalapplication of solar power caused the market and researchers’ widespread concern. Atpresent, the distributed photovoltaic inverter system is also facing a lot of problems inthe process. Including the power quality requirements: Distributed photovoltaic powergeneration system in grid-connected mode is very easy to generate harmonic oscillation.So the grid operators institute strict requirements on grid-connected distributedphotovoltaic inverter. Stability and safety requirements: Distributed photovoltaicgrid-connected system is required to maintain the stability and security of the state inthe process of work. It is also easy to produce current voltage fluctuation in loadmutation and working environment changing.The main research of this paper contents as follow:1This paper analyzed the photovoltaic grid-connected inverter principle and circuitsystem. Analyzed nonlinear phenomena in grid-connected photovoltaic system.According to the application needs researched the performance optimization ofgrid-connected photovoltaic system.2The dual operation mode of grid-connected photovoltaic system is researchedbecause of its effection in system. This paper made comparative analysis betweentraditional PI control and fuzzy control and researched mathematical model ofgrid-connected photovoltaic system under different control strategy3This paper offered a smooth and seamless work mode switching strategy fordistributed photovoltaic grid-connected system and designed the hardware circuit. Itdesigned a software control strategy and the simulation to verify the feasibility of thecontrol method.4, At last this paper designed an experimental prototype based on the TI DSPdevice TMS320F2407.