Research On Front-end DC/DC Converter Of Photovoltaic Generating System With DC Bus

As a clean energy in the future erergy field, photovoltaic generating has becomean important academic topic at home and abroad. This paper focus on the photovoltaicgenerating system with DC bus. In order to make the generating system operatecoordinate and stable, the paper analyses the energy management strategy of thegrid-connected photovoltaic generating system. The research focus on maximumpower point tracking(MPPT) and front-end DC/DC converter.In terms of MPPT, this paper respectively models the photovoltaic modules andsimulates the output characteristic of the photovoltaic modules under uniformillumination and partial shading conditions. Based on the analysis of the photovoltaicmodules’ output characteristics, the maximum power point tracking algorithms areanalyzed and studied when the photovoltaic modules under uniform illumination andpartial shading conditions.This paper presents an improved current-fed half-bridge converter as thefront-end DC/DC converter of the photovoltaic generating system with DC Bus, so asto match the photovoltaic modules with the DC bus voltage. Aiming at the voltagespike problem existing in the traditional current-fed half-bridge converter, softswithching technology is added in the traditional type. The characteristics of theimproved type is analyzed. The simulation results of the traditional and improvedcurrent-fed half-bridge converter under MATLAB/Simulink simulation environmentverify the soft switching state of the improved circuit.Combined the perturbation and observation method with improved half-bridgeconverter, a simulation model of photovoltaic generating system with DC Bus is setup. Through simulating the output power of the improved half-bridge converter whenthe environment changes and Comparing the output power of the traditional andimproved half-bridge converter, the results verify the feasibility and higher efficiencyof the improved converter in photovoltaic generating system.