Research On Grid-connected Photovoltaic Inverter Control System Based On Predictive Control

As a clean energy,solar energy has been widely concerned,and photovoltaic power generation has been the main form of solar energy utilization.Research on photovoltaic power generation system has become a hotspot of new energy power generation.In this paper,the photovoltaic power generation grid-connected inverter system is taken as the research object.Considering the two main control problems of maximum power point tracking and grid-connected inverter in photovoltaic system,the controller based on predictive control is designed to achieve the maximum power point tracking and grid-connected inverter control.The main work and contributions of this paper are as follows:Firstly,for the maximum power point tracking of photovoltaic system,this paper designs a photovoltaic maximum power point tracking controller based on predictive control.The two-step I&C method and the MPPT misjudgment mechanism is proposed to obtain the reference voltage at the maximum power point of the photovoltaic system.Meanwhile,the controller predicts the future average current and only needs to optimize cost function without PWM module.Consequently,the design of the whole system will become simple.Secondly,for the problem of photovoltaic grid-connected inverter control,this paper proposes a current control method based on predictive control.The output current is predicted by selecting the switching state directly,and the PWM module is not needed.Simultaneously,by adding the common mode voltage suppression term in the objective function,the negative impact of the common mode voltage can be reduced.The proposed controller has clear design idea and simple parameter adjustment,which can achieve grid-connected inverter control.Finally,this paper applies the proposed predictive controller to the two-stage photovoltaic grid-connected inverter system.The simulation experiment is designed to achieve the maximum power point tracking and grid-connected inverter control of photovoltaic system,which verifies the validity and reliability of controller design.