МОДЕЛЮВАННЯ КОМБІНОВАНОЇ СИСТЕМИ ЕЛЕКТРОЖИВЛЕННЯ ЛОКАЛЬНОГО ОБ’ЄКТУ З БАГАТОФУНКЦІОНАЛЬНИМ ПЕРЕТВОРЮВАЛЬНИМ АГРЕГАТОМ ФОТОЕЛЕКТРИЧНОЇ БАТАРЕЇ

Purpose. The development of a detailed mathematical model of the system "network - multifunctional converter unit with a photovoltaic battery - load", which will allow for a comprehensive study of the processes in the system with an assessment of the efficiency of the unit. Methodology. Synthesis of the structure of the model and the control system of the unit based on the analysis of processes in electrical circuits using computer simulation. Findings. Dependencies for approximating the current-voltage characteristics of a photovoltaic battery. The use of a standard model of a transformer with magnetic circuit saturation as a nonlinear reactor is proposed. A model for determining power losses in semiconductor switches by the instantaneous values of currents and voltages and their catalog data. Originality. The mathematical model of the photovoltaic battery is improved according to the passport data with the introduction of the dependence of the open circuit voltage on the intensity of solar radiation. The structure of the control system with an internal current control loop and switching external controllers according to the operating modes has been improved: when working with the network in the "day" mode, it is the voltage controller of the photoelectric battery, in the "night" mode it is the inverter input voltage controller; in standalone mode - load voltage controller. There is a justified change in the settings of the current control loop and the modulation frequency in the standalone mode to eliminate the growth of power losses in the switches. Practical value. The obtained solutions are the basis for the design and analysis of indicators of multifunctional converting units for systems with renewable energy sources with improved energy efficiency. [ABSTRACT FROM AUTHOR]