Contents lists available at ScienceDirect Journal of Energy Storage journal homepage: www.elsevier.com/locate/est Power management control strategy using physics-based battery models in standalone PV-battery hybrid systems Mayur P. Bonkile, Venkatasailanathan Ramadesigan ⁎ Department of Energy Science and Engineering, Indian Institute of Technology Bombay, India ARTICLEINFO Keywords: Standalone PV-battery hybrid system Lithium-ion battery Power management control strategy Maximum power point tracking Single particle model DAE-based MPPT ABSTRACT The rechargeable lithium-ion batteries (LiBs) are becoming a technology of choice for energy storage applica- tions, 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 ra- diation 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. 1. Introduction Solar photovoltaic (PV) power plants have emerged as a viable option to satisfy our increasing energy requirement and reduce our dependence on fossil fuels. If we want to satisfy the energy demand of the global population, which is increasing continuously, we have to double our present rate of energy production by 2050 [1]. It is neces- sary for developing countries to utilize the full potential of renewable resources to meet the growing energy demand and energy security. A number of remote villages are still unelectrified as they are situated far from the main grid and the standalone PV systems are perfect for such isolated locality. A battery-less PV-diesel microgrid with optimal op- erating strategy can also provide an uninterrupted power supply and reduce the total dispatched energy cost [2]. However, it may not be an environmentally friendly alternative due to the reliance on fossil based fuels. It is economical to install hybrid generation systems (PV/wind/ hydro) by producing and consuming power without transmitting over long distances [3]. However, a standalone PV system is an inadequate source of electricity because of power fluctuations created by varying solar radiation and unavailability of power during the night. Hence, to provide uninterrupted power throughout the day and night, a battery energy storage (BES) system can be combined with a standalone PV system [4]. Such standalone PV-BES hybrid systems can satisfy the load demand under all operating conditions. The economic viability of the PV-BES hybrid system was investigated to optimize the system opera- tion [5,6]. Mansour Alramlawi et al. [7] demonstrated the economic feasibility of a residential PV-BES hybrid system by applying economic model predictive control to optimize the operation. Secondary lithium- ion batteries (LiBs) are a very promising choice for energy storage in PV-BES hybrid systems due to its high energy density (100 Wh/kg), power density (300 W/kg), suitable operating temperature range, re- latively long battery life and operating voltage [8]. LiBs will be more economical in the near future as its price is decreasing at 8–16% an- nually [9]. Use of different battery models in simulating the PV-BES hybrid system is an active area of research. The LiB models proposed by the researchers till now can be categorized into two broad groups, physics- based and empirical/equivalent circuit models. There are various kinds of equivalent circuit models (ECMs) for LiB from basic resistor -capa- citor (RC) models to series/parallel combination of RC models that are available in the literature [10–13]. The standalone PV-BES hybrid system described by Natsheh et al. [14], consists of ECM for simulating the battery performance. A new model for a PV-battery-diesel microgrid was proposed, which calculated battery state of charge (SOC) value https://doi.org/10.1016/j.est.2019.03.016 Received 18 December 2018; Received in revised form 16 March 2019; Accepted 17 March 2019 ⁎ Corresponding author. E-mail address: venkatr@iitb.ac.in (V. Ramadesigan). Journal of Energy Storage 23 (2019) 258–268 2352-152X/ © 2019 Elsevier Ltd. All rights reserved. T