Research On MPPT Technology Of Independent Photovoltaic Power Generation Control System

All countries in the world have continuously increased their energy consumption in pursuit of economic growth,causing serious environmental pollution and depleting resources.Solar energy is one of the effective ways to replace the traditional energy because of it’s infinite storage,extensive distribution,environmental protection and no pollution.In this context,this paper combines the actual application,based on the theoretical analysis,designed a small independent photovoltaic power generation system.The system is a multi-level photovoltaic power generation system composed of a photovoltaic cell,a synchronous Buck converter,a battery,a push-pull step-up converter and a full-bridge inverter.The algorithm of maximum power point tracking and the hardware design of the whole system are the main contents of the research and design.By analyzing the output characteristics of photovoltaic cells,the necessity of MPPT algorithm is demonstrated.Combined with the practical application of the environment,this paper MPPT control strategy selection based on power prediction of variable step disturbance observation.The control algorithm can ensure the tracking speed and control accuracy,and can effectively eliminate the error and misjudgment,which is very practical.Inverter part choice the high-frequency active clamp boost and full-bridge inverter combination,compared with the application of mature power frequency inverter,can greatly reduce the size of the system and reduce costs.In the high-frequency step-up with active clamp push-pull structure,this measure can effectively solve magnetic leakage problem in the main transformer of the push-pull converter,can improve the overall conversion efficiency.In the entire bridge inverter part,adopt the inverter control strategy based on repetition and PI control.This strategy can effectively track load disturbances,to minimize the system instability caused by load disturbances,and can reduce the ramp,correction to make the waveform smooth,with great engineering value.