Study On Single-Phase Grid-Connected Inverter Of Small-Scale Wind Power Generation

With the development of economy, the energy problem has become the primaryissue related to human being’s survival and development. As the core part of the grid-connected power system of renewable energy, the grid-connected inverter receivesmore and more attention. This dissertation mainly focuses on the single-phase grid-connected inverter of small size wind power, analyzes and studies the topologicalstructure and control method of grid-connected inverter.Firstly, the dissertation chooses grid-connected inverter with pre-stage isolatedDC-DC converter as the topological structure of main circuit, based on comparingand analyzing several common topological structure of grid-connected inverter ofwind power. To make the output direct voltage of full brige converter stabilize in the350V, the pre-stage isolated DC-DC converter adopts voltage closed-loop control. Tomake the output current track the grid voltage, the post-stage DC-AC inverter adoptscurrent closed-loop control. The simulation model is established by using MATLABsoftware.Secondly, digital phase lock and anti-islanding detection is the two technicaldifficulties of the design of single-phase grid-connected inverter. Based on the ideaof using digital control, this dissertation designs digital phase-locked loop using thecapture module of the main control chip and adopts voltage-frequency method whichis concenient to use digital processing chip to control to detect islanding.Finally, a2kW model machine is produced using the digital processing chipTMS320F2812as the main control chip. The main circuit parameters is exactlycalculated, the main control circuit is designed and the software flow chart are givenaccording to the system design requirements. The result of experiment andsimulation proves that the control method is effective.