Level voltage levels/states of charge are maintained among a plurality of high voltage DC electrical storage devices/traction battery packs that are arrayed in series to support operation of a hybrid electric vehicle drive train. Each high voltage DC electrical storage device supports a high voltage power bus, to which at least one controllable load is connected, and at least a first lower voltage level electrical distribution system. The rate of power transfer from the high voltage DC electrical storage devices to the at least first lower voltage electrical distribution system is controlled by DC-DC converters.
U.S. GOVERNMENT RIGHTS
This disclosure was made with United States government support under Award No. DE-EE0003303 awarded by the U.S. Department of Energy. The United States government has certain rights in this disclosure.