Modular Battery Management System interface to integrated Vehicle Control Unit : Creating a BMS playground using Arduino

Abstract: Development today has moved more towards battery technology, partly due to the increased demand of electric vehicles (EVs). The quest for a sustainable society is at an all-time high, with electrification of almost all devices only being the beginning. Due to the use of the fragile Lithium-Ion battery, a system that controls and monitors the battery must be implemented to ensure that it operates normally. A system like this is often referred to as a Battery Management System (BMS), in this case for Lithium-Ion batteries. The objective in this thesis is to construct a modular BMS playground for NEVS in Trollhättan to continue development on. The interface for the system will consist of Controller Area Network (CAN), a fast and robust communication protocol used in almost all personal vehicles today, and Isolated Serial Peripheral Interface (isoSPI), an isolated adaptation of one of the most common communication protocols used in sensors and microcontrollers so far. The BMS will be constructed of four individual subsystems using Arduino, each with a different purpose. These four subsystems are later merged into one BMS system to offer communication between CAN and isoSPI, thus supporting a future integration of this BMS to the Vehicle Control Unit of an EV. Moreover, since the BMS is going to be developed for a vehicle, modes for engaging the vehicle to drive and stop will be made. In order to provide some safety measures, automatic disconnection of the battery in case of an error will be added. The BMS with the previously mentioned features, also capable of doing voltage measurements with a safe connection/disconnection of the battery was then made. Features such as current and temperature monitoring were omitted due to time constraints and will in the future instead be done by NEVS along additional features. This thesis was conducted by Karlstad University and NEVS in Trollhättan, Sweden.