Research And Realization Of Control Method Under Single-phase PV Inverter Based On MATLAB

Compared to the three-phase inverter technology, single-phase photovoltaic inverter technology has lots of advantages such as its small and medium-power applicability, mature technology and simple structure,so it has been widely applied in diverse areas. The nonlinear characteristics of the load in single-phase photovoltaic inverter system caused a lot of harmonics of the output. Meanwhile, electronic equipment now needs better performance of the power, so a revolutionary improvement of inverter output quality has been put forward. For single-phase photovoltaic off-grid systems, using the non-deadbeat control method, the load voltage can fleetly and accurately tracks to the reference value, but the poor robustness of the algorithm is bad. In this paper, a new closed dual-loop control method which combines the non-deadbeat and single modified neuron self-adaptive PID control strategy has been presented. This algorithm integrates the advantages of the two kinds of control algorithms, abandon the disadvantages, it can obtain better output waveform. For single-phase grid-connected inverter system, feed-forward control strategy of grid voltage and dual-loop control strategy with grid current feedback and capacitor current feedback make the system for a variety of loads and the grid voltage disturbances have good outputs. In addition, the control property of Digital Signal Processor (DSP) is gradually increased and power electronic devices are digital, integrated developing, so the competitive stunts of company is to shorten the product development cycles and reduce development costs. In this paper, MATLAB-based integrated development concept of single-phase photovoltaic inverter control algorithms proposed by Mathworks company is applied to TI C2000 series 2808DSP chips to meet the current high standard needs of the design and development market.Firstly, the paper describes the social needs of model design based on MATLAB platform as well as development in domestic and overseas. Then, the paper describes the actual market demands and the more commonly used control algorithms of the single-phase PV off-grid and grid inverter system. Because those algorithms always have disadvantage one way or another, new control algorithms based on this are proposed and applied to the DSP. Through the modeling, design and simulation of the new algorithm, the output filter and the sampling circuit based on MATLAB/Simulink, it verified the feasibility and advantage of the algorithm. Meanwhile, the use of development concept of model-based design, model validation, code optimization tools and test tools enables algorithm development and verification simultaneously. When the simulation results meet the requirements and then build the algorithm code model, the control algorithm program could be generated and downloaded to prototype automatically by the MATLAB Simulink Coder toolbox. Finally, the testing results in prototype proved that the new control algorithms based on MATLAB model have excellent quality and feasibility in single-phase photovoltaic off-grid and grid connected inverter system, but also it proved that compared with the traditional algorithm development model, model-based design clearly has the advantages such as shorten the development cycle and lowered the cost.