Development of Passive Battery Management System at TRL 4

Abstract

Nowadays, the usage of the electric vehicle (EV) is exponentially increasing. Therefore, a battery management system (BMS) is required to properly operate the Li-ion battery used in electric vehicles for extending the battery life. The main function of BMS is to sense the voltage, current, and temperature of the battery and cells independently. Further, it evaluates different parameters from the data fetched by the BMS. Finally, based on the evaluation, it controls the cell balancing. Presently, BMS is implemented using different microcontrollers and is under improvement with the advancement in existing technology. Passive balancing is commonly used in BMS, since, it is inexpensive and straightforward to implement. The passive resistor uses the passive balancing method to discharge the battery’s excess charge. For small battery capacities, this resistor is very useful. This paper analyses BMS design which combines a power resistor and transistor as a balancing resistor. The proposed analyses were applied to a battery pack consisting of 13 lithium-ion battery cells which enabled a fast-charging scheme. The most significant features of the passive balancing system are based on the results of this experiment, taking into account the impact on battery performance and energy loss. The aim of this paper is to make a battery pack that is with high energy carrying capability and proper thermal runaway. Thus, extensive monitoring is needed to operate the battery within specified operating limits to avoid fire hazards and explosions. In order to achieve this, the proposed design creates a demand for a Sophisticated management system which not only optimize the power drawn from battery but also maintain the battery operation within specified limits.