Cummins Inc.
DC-DC-CONVERTER-BASED ACTIVE VOLTAGE-BALANCING SYSTEM AND METHOD FOR PARALLEL BATTERY PACKS

Abstract:

The present disclosure provides a circuit for balancing voltages of battery packs to be connected in parallel, comprising: IN-side and OUT-side switches; a DC-DC converter with an IN terminal connected to the IN-side switches and an OUT terminal connected to the OUT-side switches; and a controller to operate an IN-side switch to connect a V.sub.max battery pack to the IN terminal, operate an OUT-side switch to connect a V.sub.min battery pack to the OUT terminal, and activate the converter to transfer energy from the V.sub.max pack to the V.sub.min pack. The controller responds to an IN terminal voltage being sufficiently close to a first battery pack voltage by operating an IN-side switch to connect the first pack to the IN terminal, and responds to an OUT terminal voltage being sufficiently close to a second battery pack voltage by operating an OUT-side switch to connect the second pack to the OUT terminal.