Battery Management System (BMS) Evaluation Toolset

The military is currently pursuing the development of advanced battery systems for ground vehicles. Battery Management Systems BMS are required for safe operation and performance optimization. The military will utilize technologies from any qualified source, so battery electronics may widely vary. Consequently, the military has the need to develop standard protocols for evaluating BMS using modeling and hardware in the loop simulation. To this end, the goal of this project has been to develop the capability to independently test and evaluate Battery Management Systems for the Army and to use this capability to test an existing BMS. Under this project, the U.S. Army TARDEC has acquired a Hardware-in-the-Loop HIL battery pack simulator which is capable of imitating the voltage profiles of lithium ion battery cells. The system was calibrated and a terminal block system was built to easily connect the HIL to future BMS that the Army needs to test. We utilized the HIL to examine a BMS that was part of a battery module developed under a previous program. The voltage simulators of the HIL were used to simulate the seven cells in that module and replicate all possible faults the BMS was designed to detect. Additionally, the HIL was used to simulate battery charges and discharges so that the output data of the BMS could be compared to the output of the HIL for accuracy. Finally, we repeated this testing with the BMS in a cold temperature chamber to see if the performance of the BMS was affected. Through this process, we have successfully developed a methodology for evaluating future Battery Management Systems and we were able to apply this methodology to a sample BMS. The fundamental BMS tests, procedures and BMS HIL guidance that we developed in this effort will provide valuable lessons-learned to build on in future, more comprehensive BMS investigations.