Mode analysis and parameter selection of voltage inverter and maximum power controller of a stand-alone photovoltaic station

The purpose is to develop a methodology for selecting the parameters of the main components of a stand-alone photovoltaic station: a step-down voltage inverter and a maximum power point search controller, which ensure the most efficient conversion and use of solar energy. The analysis of modes and energy characteristics of solar cells under different lighting conditions and temperature is carried out using equations describing physical processes in the equivalent electrical circuit of a photoelectric converter. The dynamic modes of a stand-alone photovoltaic station are simulated in the MatLab/Simulink software package. The main energy characteristics are analyzed and mathematical models of the components of a stand-alone photovoltaic station are developed in order to study the tracking modes of the maximum power point. The necessary conditions for matching solar battery and voltage inverter parameters to track the maximum power point are determined. An original methodology and an algorithm for calculating and selecting parameters of the main elements of a photovoltaic station are developed. Consideration is given to the practical example of calculating and selecting parameters of a voltage inverter and maximum power digital controller of a stand-alone photovoltaic station. The simulation results of dynamic modes of the photovoltaic station show that the voltage inverter and the maximum power controller with the parameter values selected according to the proposed methodology provide reliable and effective tracking of the maximum power point in all five considered test cases of sudden changes in solar cell illumination. The tracking accuracy is at least 98.2%, and the inverter efficiency in all the modes considered is at least 93.2%. The operating ranges of energy characteristic variation of the main elements of a photovoltaic station correspond to the calculated values obtained under their design.

photovoltaic station, maximum power controller, step-down voltage converter, computer simulation, solar battery parameters, calculated values