Patent ID: 7520353

Claim:
A hybrid vehicle, comprising: at least two wheels, operable to receive power to propel said hybrid vehicle; a first alternating current (AC) electric motor, operable to provide power to said at least two wheels to propel said hybrid vehicle; a second AC electric motor; an engine coupled to said second electric motor, operable to provide power to said at least two wheels to propel the hybrid vehicle, and/or to said second electric motor to drive the second electric motor to generate electric power; a first alternating current-direct current (AC-DC) converter having an AC side coupled to said first electric motor, operable to accept AC or DC current and convert the current to DC or AC current respectively; a second AC-DC converter coupled to said second electric motor, at least operable to accept AC current and convert the current to DC; an electrical storage device coupled to a DC side of said AC-DC converters, wherein the electrical storage device is operable to store DC energy received from said AC-DC converters and provide DC energy to at least said first AC-DC converter for providing power to at least said first electric motor; and a controller, operable to start and stop the engine to minimize fuel consumption, wherein said controller is further operable to: start and stop said engine at any speed of said hybrid vehicle; disable engine operation when vehicle load on said engine results in torque less than 20% of a maximum torque output (MTO) of said engine, wherein said vehicle load comprises road load, electrical load incurred when operating said engine to store DC energy in the electrical storage device, and accessory load when supplying accessories; and enable engine operation at any required combination of its speed and its torque, except said condition of disabling operation.