Artificial Intelligence for Renewable Energy Systems

5Battery State-of-Charge Modeling for Solar PV Array Using Polynomial Regression

Siddhi Vinayak Pandey*, Jeet Patel and Harsh S. Dhiman

Dept. of Electrical Engineering, Adani Institute of Infrastructure Engineering, Ahmedabad, India

Abstract

Due to the increased demand of solar photovoltaic (PV) arrays, its integration with a battery and modeling of precise State of Charge (SoC) is a consequential parameter to understand the available battery capacity in real time domain. In this paper, the integration of solar PV array with the first-order RC circuit has been implemented utilizing the MATLAB (Simulink Library). For experimentation, the open-circuit voltage (V_oc) and the short-circuit current (I_sc) of the solar panel is considered as 36.3 volts and 7.84 amperes, respectively. The continuous fluctuating irradiance from 110,580 W/m² leads in the variation of output voltage of the solar PV arrays. Also, the variations of battery charging current, voltage across battery, and battery SOC due to variations in irradiance are examined in detail. The proposed methodology of this manuscript explains the authentic time modeling of SoC utilizing the second, third, fourth, and fifth order of a polynomial regression technique. The comparative relationship between the OCV and SoC during the charging of the model with solar PV array has been also obtained for different orders of polynomials. Quantitatively, fifth-order model outperforms second, third, and fourth by 27.5%, 26.7%, and 21.3%, ...