Hot Swapping Analysis and System Operation of Series Connected Converters in Active Battery Reconditioning Systems for Second Life Battery Applications

This paper proposes the analysis, control strategy, and procedure to achieve hot-swapping operation of series-connected power converters in an active battery reconditioning system for second-life battery application. The proposed approach, control implementation, and transient behavior during the hot-swapping are presented. This series-connected architecture will require monitoring of the inrush of output voltage as well as the tank current with individual DC-DC converters as it is distributed across the rest of the converters in the system. The proposed approach allows the whole system to operate seamlessly and without any interruption when battery packs need to be disconnected for maintenance or replaced. A 64 V, 1 kW hardware system with 2 series-connected 32 V, 500 W converters is tested to establish experimental results of the hot-swapping challenges in series-stacked converters.