Hybrid Electric Vehicle: How It Works: Green Vehicles Articles: Eco20/20

Hybrid Electric Vehicle: How It Works

Slowly but steadily, more and more car manufacturers are introducing hybrid electric vehicles on the market. New models are becoming available globally together with the usual gasoline-powered cars at the average car dealer. Toyota's Prius and Honda's Insight are two successful hybrid electric vehicles launched initially more than ten years ago, but which in time have been improved and re-released under new generations. Countries like Japan, the United States, the Netherlands, and the United Kingdom are eagerly adopting hybrid electric vehicles, topping the charts in terms of global sales. But what really is a hybrid electric vehicle and how does it work?

Basic Features

Also known as HEV, a hybrid electric vehicle is a hybrid which combines the internal combustion engine found in average cars with a propulsion system powered by electricity. The reason behind the development of hybrid electric vehicles is to outperform a conventional car in terms of performance or fuel economy and sometimes even both.

Additional devices installed in a HEV not found in a conventional vehicle include a power splitter which connects both power sources and rechargeable batteries which are placed somewhere in the back of the car and which power the electric motor.

There are quite a few types of HEVs available on the market and many others are currently in development. Each electric hybrid car works differently according to its powertrain.

* Parallel hybrids, which are efficient at faster speeds, use the electric motor and the internal combustion engine equally by connecting both of them to the mechanical transmission.

* Series hybrids, which are efficient at slower speeds, rely on the electric propulsion system to supply energy for the drivetrain while the internal combustion engine is used to produce the power needed to keep the former running.

* Power-split hybrids combine to some extent both parallel and series hybrids. They are mostly newer models from Toyota, Ford, and Lexus.

Additional Technologies

Besides combining an internal combustion engine with an electric propulsion system to achieve greater performance, HEVs also use additional advanced technologies to increase efficiency.

One of these technologies is regenerative braking. It converts the kinetic energy generated when the driver uses the brakes into electric energy which replenishes the battery. In this way, the kinetic energy generated when braking is no longer wasted as heat energy.

Another technology adopted by many HEVs is a motor-generator. It uses the internal combustion engine to spin a special electrical generator to produce electricity. The energy obtained is then used to replenish the vehicle's electric batteries.

To improve fuel economy a hybrid electric vehicle also uses a start-stop system that shuts down the internal combustion engine when it is not needed and then turns it on again when required. Because this practice reduces gas emissions, hybrid electric vehicles are more friendly with the environment that conventional cars. In addition, the gasoline internal combustion engine tends to be smaller in a HEV than in an average car because it shares duties with the electric propulsion system, further reducing emissions.

Overall HEVs are much friendlier with the environment than conventional vehicles. For this reason, in the near future they are set to become the standard in the vehicle industry, until an efficient and affordable motor that works entirely on biofuels is developed.