Modeling the Influences of Cells Characteristics in Energy Storage System for Different Forms of Discharge Current

Abstract:
In our present, Li – Ion batteries became the primary energy source not only in regular everyday consumer electronics but also in more key applications like electrified transportation and backup power source in stationary energy storages. Considering the wide range of applications and operating conditions as well as the current profiles related to it, a relatively complicated electronic circuitry called a battery management system is used in order for obtaining the best performance from the battery pack. There are tons of key parameters like State of Health, State of Charge, internal resistance, battery capacity, number of cycles and so on that need observation in terms of having as highest as possible performance. The battery condition can be estimated by knowing the battery capacity. The most common way of obtaining this information is by using the discharge method. Based on this, this paper presents a Matlab/Simulink based tool for modeling and determining the State of Charge of a Li – Ion battery pack by using a lookup tables giving an information of the battery behavior when discharging with DC current in constant current mode or high frequency pulse current with DC offset. The family discharging curves are experimentally obtained which means they are preliminary known for a particular application.