Power management control strategy using physics-based battery models in standalone PV-battery hybrid systems

Abstract

Abstract The rechargeable lithium-ion batteries (LiBs) are becoming a technology of choice for energy storage applications, due to its high energy and power density. In this paper, a power management control strategy is proposed for a standalone PV-Battery Energy Storage (BES) hybrid system. The proposed control algorithm tracks the Maximum Power Point (MPP) of the solar-cells while avoiding overcharging of LiBs under different solar radiation and load conditions. The controller has two regulation modes; (a) MPP Tracking mode, (b) battery state of charge limit mode. The standalone PV-BES hybrid system is represented as a system of differential algebraic equations and enables effective implementation of control algorithms. A physics-based single particle model accounting for internal states of a battery is implemented in the simulation and control algorithm. A mixed-order finite difference method with optimal node spacing and strong stability-preserving time-stepping Runge–Kutta scheme is used to solve the battery model. A case study is provided to demonstrate the effectiveness of the proposed strategy using real world data. The study reveals that the proposed power control strategy is robust and meets multiple objectives of standalone PV-BES hybrid systems such as no overcharging, 0% excess output power production, and ensuring no energy is transferred to the dump load.