Battery management system for multi-cell battery modules

2017 ELE Engineering Design Project (DX02)

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Faculty Lab Coordinator

David Xu

Topic Category

Power / Controls

Preamble

In modern electrical vehicles, the battery cells are packed together to form a module. Usually 12 cells are connected in series to form a module with terminal voltage at 45V (nominal). The battery management system (BMS) for each module are connected to the cells to determine the status of each cell, including the state-of-charge (SOC), cell temperature, cell voltage as well as other parameters. BMS also measure the current of the module to determine the SOC. The project is to design a BMS system for multi-cell Lithium-ion battery module

Objective

The objective of this project is to design a BMS system for 12-cell lithium-ion battery module. The BMS system should be able to determine the status of each cell.

Partial Specifications

The requirements for the BMS are:
1) Use local display to show the cell voltages, module current and module SOC
2) It can communicate with PC to show the status of the module through RS232 communication (via USB adapter).
3) Protect the module from over heating, over charging/discharging.
4) Alarm when any cell is damaged or malfunction.
5) Balance the cell capacity using resistors (passive balancing)

Suggested Approach

It is suggest to search the possible integrated IC solutions for the BMS. The group should propose the solution based on the literature survey and existing product investigation.

Group Responsibilities

Group should be responsible for finalize the design, project report and demo

Student A Responsibilities

Student A is responsible for the micro-controller. The MCU will display the status of the battery cells, cell voltage, charging/discharging current and other information on the LCD. SOC algorithm can be implemented in the MCU if necessary.

Student B Responsibilities

Student B is responsible for the battery BMS circuit design, including the design of battery cells interface, cell temperature measurement, current measurement as well as the balancing circuit.

Student C Responsibilities

Student C is responsible for the design and pack of the battery cells. It is suggested to use 18650 small battery cells to form the module. The protection circuit is the responsibility of student C

Course Co-requisites