Design And Development Of Grid-connected Photovoltaic Inverter Based On Nonideal Proportional-resonant Controller

In the situation of energy shortages, environmental pollution and nuclear safety issues oftoday’s world, solar energy is one kind of the most commercially valuable renewable energy.The grid-connected photovoltaic power generation will be an important direction of China’sfuture energy development. The grid-connected inverter is the key part of the photovoltaicsystem. With the condition of the efficiency and process technique of the PV cell nowadays,improving the efficiency and performance of the grid-connected PV inverter lies on theoptimization of control technique. A PV inverter system based on the widely applied PIcontroller has acceptable dynamic and steady-state performance. It is simple and easy toimplement but has disadvantages of steady-state error and poor anti-jamming capability to theinterference of the net. So a new control strategy is needed for eliminating the steady stateerror and strengthening the ability of anti-jamming.This paper proposes a grid connected inverter control strategy, which uses a PR controllerto eliminate the steady state error and strengthen the ability of anti-jamming. And the nonidealPR control strategy is proposed for the further improving.The major contribution of this paper is shown as follows:1, The disadvantages of the PI control strategy are pointing out by researching differentkinds of grid connected inverter control strategies.2, The PR control strategy is proposed to solve the problems. And the conclusion that aPR controller can eliminate the steady state error and strengthen the ability of anti-jamming isdeduced. And the nonideal PR control strategy is proposed for the further improving.3, The hardware and software of a grid-connected PV inverter are designed based on thenonideal PR control strategy.4, The proposal is verified by simulation and prototype experiments. Simulationexperiments of the control systems based on PI, PR and nonideal PR controllers are carriedout and the results are compared to prove conclusion of this paper. Then waveforms of theone-KW-prototype experiments are shown.Simulation and prototype experiments proved that the nonideal PR control strategyproposed in this paper, which retains the advantages of the PR controller, can use to solve theproblems of the PI control strategy. And it overcomes the shortcoming of the PR controller, sois adapt for the excursion of the grid frequency.