How Hybrid Cars Work

There are different kinds of hybrid cars. Here are some of the basic principles employed in hybrid car technology.

In traditional (internal combustion engine) cars the gasoline's chemical energy is converted by an explosion into mechanical energy, which is then transmitted to the wheels through the drive shaft.

In most traditional cars the engine is able to convert only about 30% of the fuel-generated power into actual motion, while the remainder is lost in the form of heat and noise.

Hybrid technology adds efficiency to traditional cars through a series of elements that allow a high torque electric motor to work along with its traditional gas-fueled engine. This technology allows about 50% more miles per gallon and about 30% less emissions, while offering the same performance and convenience as the equivalent traditionally powered vehicle.

Key traditional elements:
A. Internal combustion engine
B. Fuel tank

Key additional elements:
1. High-torque electric motor
2. Generator
3. High-capacity accumulator (battery)
4. Control computer

In a hybrid vehicle the high-torque electric motor (1) is powered by otherwise lost energy recaptured by the generator (2) and converted into electricity, which is then stored in the high-capacity accumulator (3). This means that a hybrid vehicle does not need to be plugged into a power grid in order to be recharged. The control computer (4) smoothly manages the system, allowing the driver to concentrate solely on driving the vehicle.

While idle, both the gas engine and the electric motor of a hybrid car are turned off. During the initial acceleration, and at low speed, the car is powered by the high-torque electric motor; the gas engine remains off and the car moves smoothly, silently, and without burning any gas.

As the hybrid car reaches about 20 mph the traditional engine smoothly kicks in, taking over the supply of power to the wheels and allowing the vehicle to reach and maintain cruising speed. During these phases some of the power provided by the traditional engine is also used to drive the electric generator, which recharges the electric motor's high-capacity battery.

When a burst of power is needed to climb up a ramp or pass a slow-moving vehicle, the control computer uses both the electric motor and the gas engine to provide extra power to the vehicle.

During breaking a regenerative breaking system is engaged along with the traditional breaks. This system connects the wheels to the electric generator to further slow down the car while converting some of the car's speed into electricity, to be stored in the high-capacity battery.