The present invention relates to electrically powered vehicles and, more particularly, to on-board charging systems for electrically powered vehicles.
Electric vehicles are typically powered by a bank of batteries carried on-board the vehicle. The electrical power stored in the batteries is used to power an electric drive motor to propel the vehicle.
In a hybrid vehicle, an internal combustion engine (ICE) is provided to either provide a charging source for the batteries as they are depleted or to provide a motive power to the vehicle when the charge has been depleted or the electric motor is insufficient to provide the requisite motive power to the vehicle.
In electric vehicles without an ICE, the range of the electric vehicle is limited by the efficiency of the drive system and the capacity of the batteries carried on-board the vehicle. Various solutions are provided for on-board charging of the batteries. Regenerative braking is one solution in which during a braking or deceleration sequence the kinetic energy of the moving vehicle is used to drive a generator to recharge the batteries. Other systems include coupling of a generator to a wheel that is driven by the vehicle when the vehicle is in motion. However, these solutions require that the vehicle be in motion to provide recharging of the batteries but do not provide a recharging source when the vehicle is stationary.
As can be seen, there is a need for an on-board charging system that can recharge a drive battery for an electric vehicle when the vehicle is stationary.