Abstract
Energy storage systems require battery cell balancing circuits to avoid divergence of cell state of charge (SOC). A modular approach based on distributed continuous cell-level control is presented that extends the balancing function to higher level pack performance objectives such as improving power capability and increasing pack lifetime. This is achieved by adding DC-DC converters in parallelwith cells and using state estimation and control to autonomously bias individual cell SOC and SOC range, forcing healthier cells to be cycled deeper than weaker cells. The result is a pack with improved degradation characteristics and extended lifetime. The modular architecture and control concepts are developed and hardware results are demonstrated for a 91.2-Wh battery pack consisting of fourseries Li-ion battery cells and four dual active bridge (DAB) bypass DC-DC converters.
Original language | American English |
---|---|
Number of pages | 10 |
State | Published - 2014 |
Event | IEEE Energy Conversion Congress and Exposition - Pittsburgh, Pennsylvania Duration: 14 Sep 2014 → 18 Sep 2014 |
Conference
Conference | IEEE Energy Conversion Congress and Exposition |
---|---|
City | Pittsburgh, Pennsylvania |
Period | 14/09/14 → 18/09/14 |
NREL Publication Number
- NREL/CP-5400-61263
Keywords
- battery
- battery pack
- energy storage
- modular