Lou Ann Hammond, the CEO, ww.drivingthenation.com, explains What is a Hybrid Electric Vehicle (HEV)? How does a hybrid automobile work? What is under the hood of an HEV that gives you 20 or 30 more miles per gallon than the standard automobile? What is regenerative braking and does an HEV pollute less just because it gets better gas mileage?
A Hybrid Electric Vehicle has:
(3) electric motor
(4) power electronics system
(5) fuel tank
(6) battery pack
Hybrid electric vehicles are a combination of an internal combustion engine (1) and a battery and electric motor (3) of an electric vehicle. In current hybrids, both the engine (1) and the electric motor (3) are connected to the wheels by the same transmission (2).
Intelligent power electronics (4) is a device that decides when to use the motor or internal combustion engine and when to store regenerated electricity in the battery (6) for future use. In a hybrid, when the brakes are applied, the motor becomes a generator. This generator uses the kinetic energy of the vehicle to generate electricity. The electricity is stored in the battery for later use.
A simple way to think of a hybrid is to think of a moped. There is a gas-powered engine and the second form of energy is your foot. Imagine if, instead of using your foot every time you needed to kick the ground, you could take the kinetic energy your body makes by pulling your foot up or setting it down and storing it on the board. That would be similar to what the battery/engine hybrid does for a vehicle.
Unlike all-electric vehicles, hybrid vehicles do not need to be plugged into an external source of electricity. Gasoline stored in a conventional fuel tank (5) provides all the energy the hybrid vehicle needs. Regenerative braking is why you don’t have to plugin.
The electric motor is used primarily for low-speed cruising or to provide extra power for acceleration or hill climbing. If you commute on the highway you will not get as good mpg as if you commuted in city traffic under 25 mph. The EPA is looking into how they calculate miles per gallon (MPG) for hybrids. To find out more about this click here.
Hybrids compensate for the shortfall in both a battery and the internal combustion engine. The battery can supply only enough energy for short trips without needing to be plugged in again. Regenerative braking takes care of this problem. The internal combustion engine is inefficient in its use of gasoline. It causes pollution in the air and makes us dependent on foreign oil. The battery side of the hybrid allows us to use less fuel, thereby creating less pollution and less dependence on oil.