Analysis and Synthesis of Architectures for Automotive Battery Management Systems

Abstract

Current batteries of battery electric vehicles (BEVs) require a battery management system (BMS) in order to enable a safe and long-lasting operation. The main functions of the battery management systems are a continuous monitoring of the voltage of each cell, a continuous monitoring of the battery temperature, the control of the charge current and the discharge current as well as the prevention of both a deep discharge and an overcharging. For the realization of these functions, different architectures are possible, ranging from an individual intelligent system at each cell up to a realization of the whole BMS within one central computing unit for the whole vehicle. This paper investigates and structures different architectural possibilities, discusses analysis possibilities and presents approaches for the synthesis of sensible architectures such as BMS. A concept synthesis for the start-up and shut-down of the high-voltage system is presented by comparing three different integrated pre- and discharging circuits and using a Hardware-in-the-Loop (HiL) program as an example. Finally, a topology consisting of three switches and two resistors (3S2R2) turns out to be the best one, due to the number of components, safety and price.

Keywords

• battery management system
• BMS
• vehicle electronics
• E/E-architecture