Advanced Cell-Level Control for Extending Electric Vehicle Battery Pack Lifetime
A cell-level control approach for electric vehicle battery packs is presented that enhances traditional battery balancing goals to not only provide cell balancing but also achieve significant pack lifetime extension. These goals are achieved by applying a new life-prognostic based control algorithm that biases individual cells differently based on their state of charge, capacity and internal resistance. The proposed life control approach reduces growth in capacity mismatch typically seen in large battery packs over life while optimizing usable energy of the pack. The result is a longer lifetime of the overall pack and a more homogeneous distribution of cell capacities at the end of the first life for vehicle applications. Active cell balancing circuits and associated algorithms are used to accomplish the cell-level life extension objectives. This paper presents details of the cell-level control approach, selection and design of the active balancing system, and low-complexity state-of-charge, capacity, and series-resistance estimation algorithms. A laboratory prototype is used to demonstrate the proposed control approach. The prototype consists of twenty-one 25 Ah Panasonic lithium-Ion NMC battery cells from a commercial electric vehicle and an integrated BMS/DC-DC system that provides 750 W to the vehicle low voltage auxiliary loads.
- Research Organization:
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- U.S. Department of Energy, Advanced Research Projects Agency-Energy (ARPA-E)
- DOE Contract Number:
- AC36-08GO28308
- OSTI ID:
- 1351867
- Report Number(s):
- NREL/CP-5400-68303
- Resource Relation:
- Conference: Presented at the 2016 IEEE Energy Conversion Congress and Exposition (ECCE), 18-22 September 2016, Milwaukee, Wisconsin
- Country of Publication:
- United States
- Language:
- English
Similar Records
Active Reconditioning of Retired Lithium-ion Battery Packs from Electric Vehicles for Second Life Applications
DOE Hybrid and Electric Vehicle Test Platform