Direct, Efficient, and Real-Time Simulation of Physics-Based Battery Models for Stand-Alone PV-Battery Microgrids

With renewable energy based electrical systems becoming more prevalent in homes across the globe, microgrids are becoming widespread and could pave the way for future energy distribution. Accurate and economical sizing of stand-alone power system components, including batteries, has been an active area of research, but current control methods do not make them economically feasible. Typically, batteries are treated as a black box that does not account for their internal states in current microgrid simulation and control algorithms. This might lead to under-utilization and over-stacking of batteries. In contrast, detailed physics-based battery models, accounting for internal states, can save a significant amount of energy and cost, utilizing batteries with maximized life and usability. It is important to identify how efficient physics-based models of batteries can be included and addressed in current grid control strategies. In this paper, we present simple examples for microgrids and the direct simulation of the same including physics-based battery models. A representative microgrid example, which integrates stand-alone PV arrays, a Maximum Power Point Tracking (MPPT) controller, batteries, and power electronics, is illustrated. Implementation of the MPPT controller algorithm and physics-based battery model along with other microgrid components as differential algebraic equations is presented. The results of the proposed approach are compared with the conventional control strategies and improvements in performance and speed are reported. (C) The Author(s) 2017. Published by ECS. All rights reserved.