Control Methods For Maximum Power Point Tracking Of Photovoltaic System

With the rapid development of world economy， the traditional energy sourcesdried up， the environmental pollution is increasingly serious， new energy has becomethe21st century economic development in the world the most decisive factor. Includingsolar energy because of its huge reserves， clean the advantages of no noise popularity，photovoltaic power generation technology and industry， therefore， not only becomean important in today’s energy supplement， but also has the potential to become futureprimary energy source. Maximum power point tracking control is the core ofphotovoltaic power generation technology， the research for improving the workefficiency and reduce operating costs of system has very important theory significanceand practical value.In recent years, domestic and foreign scholars have done a lot of research onmaximum power point tracking (MPPT) of photovoltaic system, and have made manyachievements, but there is still much room for improvement. Many control method cansuccessfully track the maximum power point, but the effect is not ideal enough intracking speed, accuracy, etc. And some control methods due to the complexity of thealgorithm are difficult to implement in practical system.Based on the photovoltaic power generation system as a platform, the algorithms ofMPPT are discussed, and the main work is as follows.Firstly, the presently application and development situation of photovoltaictechnology at home and abroad are introduced, the principle of the solar panel isanalyzed, and simulation results confirm the output characteristics of the solar cell.Secondly,4kinds of typical DC-DC converter are introduced, through comparison ofcharacteristics for different DC-DC topologies, Boost converter is selected as the MPPTcontroller. Finally, through the comparative analysis of several commonly used MPPTcontrol methods, an improved variable step size INC MPPT algorithm is proposed, andincremental conductance method step change trigger conditions are improved.Simulation results show that the proposed algorithm has a faster response speed andhigher tracking accuracy in sudden large irradiance changes.