Basic Technology of Hybrid Vehicles Explained
Petroleum-based fuels are ideally suited for internal combustion engine technology, which has powered most cars and trucks for over a century. Burning fossil fuels for over a hundred years however has done some serious damage to the ecology of the planet. Enter the electric vehicle with lower emissions, but correspondingly lower power. Finally, both technologies have come together in hybrid vehicles, also known as hybrid electric vehicles or HEVs.
Present-day hybrid vehicles are equipped with both gas internal combustion engines and electric motors. The gas engine produces power through small and continuous controlled explosions that push pistons which turn a rotating crankshaft. The force created by the rotation crankshaft is transmitted through a number of components and ultimately turns the vehicle's wheels. The electric motor is powered by a battery which creates energy through a chemical reaction. The battery is continually recharged by a generator that is powered by the internal combustion engine.
Hybrid vehicles are of parallel or series design, or a combination of the two.
In parallel design vehicles, the electric propulsion system and the energy conversion unit are connected directly to the vehicle's wheels. The gas engine is used for highway driving and the electric motor acts an assist and provides additional power for acceleration, hill climbing, and other situations that require more power.
In series design vehicles, the gas engine is connected to an electricity producing generator. This electricity is used to power an electric motor, which in turn powers the vehicle's wheels. Hybrid vehicles can also be designed to use the series configuration at low speeds, and the parallel configuration for acceleration and highway driving.
Braking in conventional vehicles generates heat. This energy is wasted. Some hybrid vehicles convert this energy to electricity and use it to help propel the vehicle. This process is called regenerative braking and contributes to the overall efficiency of the vehicle.
Other hybrid vehicles extend the life of the car's on-board battery system by using ultracapacitors. The ultracapacitor is more efficient than a battery for capturing the energy from regenerative braking and utilizing it for initial acceleration.