Patent ID: 8653696

Claim:
An apparatus comprising: a first energy storage device configured to supply electrical energy; a bi-directional DC-to-DC converter coupled to the first energy storage device; a DC bus coupled to the bi-directional DC-to-DC converter; a first bi-directional inverter coupled to the DC bus; a first electromechanical device coupled to the first bi-directional inverter; a charge bus comprising a first conductor directly coupled to the first bi-directional inverter and an external power source and a second conductor directly coupled to the first electromechanical device and the external power source; and a controller configured to: selectively control switching of the first bi-directional inverter to: convert a DC voltage on the DC bus into an AC voltage suitable for supplying to the plurality of conductors of the first electromechanical device; and convert the charging voltage that is supplied to the plurality of conductors of the first electromechanical device into a DC voltage suitable for supplying to the DC bus for charging the first energy storage device.