Advanced Projects Research, Inc. (APRI) has developed advanced power management technology for high-voltage, high-power batteries, which directly addresses the recognized need for monitoring and controlling battery function at the cell level. The developed approach systematically integrates physical hardware, cell level mathematical models, advanced nonlinear identification algorithms, and model-based feedback control laws into one system. This system can provide real-time estimation of state-of-charge and state-of-health and can control state-of-charge of each individual cell in high-voltage, high-power battery packs. The hardware developed by APRI is used to sense cell conditions, such as temperature, voltage and current, and to communicate these conditions in an efficient, accurate and inexpensive way. Effectiveness of the designed system has been demonstrated through its implementation in a 24-cell battery pack with pack level voltage over 30V. Testing of the system shows that the evolution of state of charge of individual cells can be accurately estimated, the deterioration of state of health of single cells can be effectively monitored, and state-of-charge among cells in a high-voltage, high-power battery pack can be balanced. Benefits of the developed battery management system include increased cycle life and effective capacity; improved reliability, and reduced cost of ownership. The system architecture allows for scaling to very high-power, high voltage battery systems.
Inquiries concerning APRI's High Voltage Battery program should be directed to Dr. Thomas Sobota at Thomas.Sobota@apri.com