Research on MPPT Algorithm Based on Variable Step Size Conductance Increment + PI Method

With the economic and social development of many countries in the world, more and more countries pay attention to the green and sustainable use of energy. Because of its unique advantages, solar energy has been widely favored by many countries in the world. However, the input parameters of photovoltaic (PV) cells change with the environmental factors, in order to make PV cells always output maximum power, it is necessary to carry out effective Maximum Power Point Tracking (MPPT) control strategy. In order to solve the problem that the single algorithm cannot be both rapid and stable, the conductance increment method is improved in this paper, and the combination algorithm of variable step conductance increment + PI controller is adopted. In the grid-connected system, verify the tracking characteristic of the output power of the high-power PV array by the variable-step conductance increment + PI algorithm. The simulation results show that the proposed control method can not only track the change of external environment fast, but also has better response speed and control precision, at the same time also can effectively restrain power oscillation phenomenon near the maximum power output point.