A portable range extender can be used to supply electrical power to an
electric vehicle operable by an electric traction motor. The portable
range extender includes an engine, a dynamoelectric machine coupled to
the engine by a shaft, an autonomous range extender controller for
controlling operations of the range extender independently of a
controller for the vehicle, and circuitry associated with the engine and
machine. To start operation, electrical energization is applied from the
vehicle battery to the dynamoelectric machine for operation as a motor to
drive the shaft. As the shaft accelerates, the rotational speed of the
shaft and the temperature of the engine are sensed. When the speed and
temperature obtain predetermined thresholds, fuel is supplied to the
engine and ignition is activated. The engine then operates as a prime
mover to drive the shaft in lieu of the machine. After a period of engine
prime mover operation, the machine is activated for operation as a
generator to provide an electrical current output for charging the
battery or supplying energy to the traction motor. When range extender
operation is to be stopped, fuel supply is cut off before ignition
termination to avoid engine backfire.