Patent ID: 7474066

Claim:
A method for supplying electrical power to a DC supply bus of a rotating electric motor of an electric vehicle comprising the steps of: selectively supplying electrical power to the bus via a first power supply at a first alternating voltage by: coupling the first power supply to a primary winding of a transformer; coupling a first terminal of a secondary winding of the transformer to the bus via a rectifier booster circuit and a current surge limitation circuit, the first terminal having a first winding ratio; and coupling the first terminal to the bus via the rectifier booster circuit but not the current surge limitation circuit after a direct voltage in the bus exceeds a first predetermined value; and selectively supplying electrical power to the bus via a second power supply at a second alternating voltage that is less than the first alternating voltage by: coupling the second power supply to the primary winding of the transformer; coupling the first terminal to the bus via the rectifier booster circuit and the current surge limitation circuit; coupling, when the direct voltage in the bus exceeds a second predetermined value, the first terminal to the bus via the rectifier booster circuit but not the current surge limitation circuit, and rectifying and increasing the second alternating voltage provided by the first terminal; and coupling, when the direct voltage in the bus exceeds a third predetermined value, a second terminal of the secondary winding of the transformer to the bus via the rectifier booster circuit, the second terminal having a second winding ratio greater than the first winding ratio.