Workshop Overview
Lithium-ion batteries are considered as the only viable energy storage solution for the large deployment of plug-in hybrid electric vehicles (PHEV). The main issues of lithium-ion batteries include capacity fade, cycle life, and safety. The safety and longevity issues are significantly magnified in large battery systems used in PHEV and renewable energy systems. Much of the work at the present time is focused on battery chemistry and manufacturing process improvement. However, these issues can be effectively addressed from the control and management perspective, with a power electronics based solution. This presentation discusses the management of lithium-ion battery systems aimed at improving battery life, available capacity, battery safety and reliability in PHEV with power electronics based solutions.

The power electronics based solutions use isolated charge architecture to provide effective and safe cell-balancing during charge with reduced charging time, and a dynamic balance circuit during discharge to utilize all the cell energy available. Every cell tightly balances during charge and discharge in any combination of rows, modules, arrays, or strings of batteries. An effective thermal design and management are included to extend battery life, along with health monitoring, fault detection and fault isolation. Additional features of the system include conditioning vehicle system with a bidirectional converter for cold weather performance improvement. A number of fundamental issues were identified in the research, including dual phase-shift control algorithm, model based predictive control that combines online load parameter identification and dead-band compensation, and a framework for the research of short timescale transients in high power converters.