It is known to provide a hybrid electric vehicle (HEV) configured for operation in a series mode in which an internal combustion engine is employed to drive an electrical generator for charging a battery and powering an electric motor. The series arrangement has the advantage that the engine may be operated at a substantially constant speed, allowing an improvement in efficiency of power generation by the engine. The speed may be selected to be a speed corresponding to that at which maximum operating efficiency of the engine is obtained.
It is an aim of the present invention to provide an improved HEV and an improved method of operating a HEV. Embodiments of the invention may provide an apparatus in which energy recovered during braking of the vehicle is used by the generator, operating as a motor, to maintain rotation of the internal combustion engine and thereby improve regenerative braking capability. Other aims and advantages of the invention will become apparent from the following description, claims and drawings.