Solar Grade Two With Single-stage Inverter Research

Today’s society,the new energy is becoming increasingly important, so is to improve the efficiency in the use of new energy. At present, the conversion efficiency of PV panels is relatively low,so as to improve the power utilization of photovoltaic cells.In light of this,MPPT technology to improve the utilization of photovoltaic cells have developed rapidly.This paper first analysis of several MPPT technology.For the more common incremental conductance method,analyze its strengths and weaknesses.Against its shortcomings, an improved version of the incremental conductance algorithms have been proposed.Establish a MATLAB model for a two-stage adjustment of the push-pull DC inverter circuit.Traditional incremental conductance algorithm and improved algorithm were compared to verify the feasibility of this algorithm.In order to improve the efficiency of the inverter and to reduce the volume, high frequency link technology is now widely used.Mainly there are two-stage and single-stage topology.Two-stage topology using the pre-push-pull forward step-up to boost low-voltage into the high voltage. Series clamp capacitor in the middle of the switch to inhibit magnetic bias of the transformer. Establish Push-pull forward small-signal model, loop transfer function is so derived.Optimized design parameters of the feedback loop to improve the stability of the inverter system. Optimize the design of magnetic circuit parameters in order to reduce the transformer losses and improve efficiency.Test the inverter in a resistive load, inductive load, the output and efficiency to achieve the design objectives.For now increasingly widely used single-stage inverter topology,based on flyback converter,analysis flyback inverter’s principle and modal.According to the current peak sinusoidal envelope modulation to calculate the switch conduction time.Thus determine the drive signal.Design the magnetic parameters, the flyback transformer and switch parameters.Establish the MATLAB simulation model, using a lock-in control module. Simulation results verify the feasibility of the design.