The Design Of DG Grid-connected Inverter And Research On Some Related Control Methods

Nowadays, with the shortage of energy resources and the problem of severe environment pollution, the distributed generations(DG) technique based on renewable energy is becoming more and more popular. The grid-connected inverter is the key element for the DG. As a result, the topological structure and control method is absorbing people's attention. The sinusoidal current wave control method is the main control problem. Real-time tracking the frequency, phase and capability demand of the grid is the goal, thus the distortion can be lower and influence to the grid can be reduced more. It's to say, to achieve the united power factor.In chapter 1, the background of research and the development at home and abroad of grid-connected inverter are discussed. The research of topological structure and control method is the emphasis.The basic working mechanism of voltage-type grid-connected inverter is introduced from the circuit topology in chapter 2. The parameters design of the components is deduced in detail.In chapter 3, based on mathematical modeling, the closed loop control system is established. The control objective and performance demand is analyzed, then improved PI control and robust control are proposed and compared. Mealwhile the controller design steps are discussed. Related simulation results proves its correction.In chapter four, the hardware and software design of the grid-connected inverter control system base on TMS320F2808 digital signal processor is introduced in detail.The 30kW three phase grid-connected inverter experimental prototype is developed. The experimental waveforms verify the validity of the theoretical and simulation analysis.The summary and future research ideas would be given at last.