Comparative Analysis of State-of-Charge Estimation for Lithimum Ion Battery in Electric Vechile Application

Abstract

As the technology of electric vehicles are evolving rapidly, the battery has arisen as the most noticeable energy storage unit. Beside the growth of the battery technology, the battery management system (BMS) is a key element to utilize the battery in a protected, dependable and productive way. This paper has been developed to identify the most accurate SOC estimation method among various SOC estimation methods commonly used by the research workers. The various methods analysed in this paper include: Fuzzy Logic method, Internal Resistance method, Particle Filter method, and Coulomb Counting method. In each method, the normal parameters of Lithium-ion Battery such as temperature, current, voltage etc. are taken into account to estimate the SOC value by using the MATLAB simulation software. The simulated SOC values of all the four methods are compared based on their advantages and disadvantages. The most appropriate method with less operational difficulty is considered as the accurate method of SOC estimation which enhances the efficiency of BMS in a battery. The battery is also equipped with suitable power modules and sensors that provides necessary data inputs and the collected data is then sent to the controller and the level and status of the lithium ion battery is monitored and estimated to the user for the benefit of the customers.