Research On Improved MPPT Algorithm For PV System Based On FPGA

With the depletion of fossil energy, solar photovoltaic power gets more and more attentions because it’s green, clean, renewable, without geographical restriction, and so on. The photovoltaic system is vulnerable to the external environment, such as light intensity, temperature, which reduces output efficiency, and these seriously restrict the PV system’s promotion and application. MPPT control technology can effectively improve the photovoltaic cells output efficiency, so it becomes the focus of photovoltaic technology research.In order to research on photovoltaic control technology, the paper analysis of the photovoltaic cell work principle, and establish engineering using mathematical model, and build simulation model to verify which bases on Matlab/Simulink platform, at last the paper analysis the output characteristics of the photovoltaic cells based on the impact of the external environment.In order to improve the output efficiency of photovoltaic system and enhance system’s adaptability to environment, this paper analysis traditional adaptive variable step size algorithm and zoning control strategy, and propose improved MPPT method bases on Power-Duty cycle differential characteristic curve. The algorithm uses the maximum points of the differential curve to realize auto tracking area division, and adopts adaptive variable step size to track MPP. the paper build photovoltaic control system simulation model based on Matlab/Simulink platform, Simulation results show the effectiveness of the algorithm.MPPT control system is the key to improve the PV system output efficiency, this paper finish the control system’s digital realization based on FPGA platform, and build multiplier module, register module, PWM signal generation module and the MPPT control module, use hardware description language to complete the control function of each module, at last the paper complete system function validation through waveform simulation based on Quartus II platform, and lay the foundation for the MPPT control Soc implementations.