Physics-based models in PV-battery hybrid power systems: Thermal management and degradation analysis

Abstract

Abstract This paper presents a thermal management and control strategy to minimise thermal degradation in Li-ion batteries in a standalone solar-PV – Battery Energy Storage (BES) hybrid power system. The main objectives of this work are: (a) to analyse the effect of temperature on the performance and degradation of the BES system, and (b) to develop a simple, cost-effective thermal management strategy to maintain the BES system temperature (during charging) in a safe operating window. Typically, battery manufacturers estimate the battery life based on standard test conditions, which may be different from the various real-world climatic conditions throughout the year. The change in temperature has a significant effect on battery degradation processes. This paper employs a physics-based electrochemical-thermal single particle model for simulating a Li-ion battery capable of capturing these effects to analyse and address this issue. Simulations for an entire year are performed using real-world solar insolation and household energy consumption data of a residential area in India. The use of physics-based model helps in understanding the thermal aspects of degradation of the BES system. The BES system is better protected against thermally driven capacity fade using the proposed thermal management and control strategy that does not use any external cooling systems.