In an electrical power supply having a plurality of switching power converter circuits and configured to supply a voltage to an electrical load, a method of controlling a duty cycle of at least one switch of one of the plurality of switching power converter circuits includes determining a storage voltage produced by the one of the plurality of energy storage devices. The method further includes determining an average storage voltage corresponding to an average of storage voltages produced by each of the plurality of energy storage devices. The method further includes determining at least one control signal as a function of the storage voltage, the average storage voltage, and a reference voltage. The method further includes controlling the duty cycle of the at least one switch of the one of the plurality of switching power converter circuits based upon the at least one control signal.