Saturday, January 24, 2009

HOW IS AN E-REV DIFFERENT FROM A HYBRID?

While it seems like there are only minor differences, the truth is an E-REV is substantially different than a hybrid. Essentially, a hybrid is a vehicle that is designed to use gasoline as its primary fuel and electricity as a supplement. At lower speeds and light engine loads, some hybrids use only electricity. At higher speeds or rates of acceleration, they operate in a “blended” mode, with both the larger gas engine and smaller electric motor running. Even the most efficient hybrids on the road only get a battery-powered boost at low speeds, while most of the time still burning gas. So while a hybrid is more efficient than a conventional internal combustion engine, under normal driving conditions it will use more gas than an E-REV operating in all-electric mode.


Volt would be the first car to flip that equation. In fact, Volt's unique advanced design has helped establish a new category — Extended-Range Electric Vehicles or E-REVs. Basically, an electric motor would drive the vehicle at all times. So you'll be accelerating, driving on the highway, going uphill — all the normal driving requirements — propelled by electric power. A small gasoline engine and a generator would kick in when the battery power is depleted after driving up to 40 miles. The gas engine and generator then produce all the electricity needed to keep driving for hundreds of miles. It's this range-extending technology that makes EREV so unique. Think of EREV as an electric car that can generate its own electricity, allowing you to continue efficiently without any worry of running out of power.


Volt would be the first car to flip that equation. In fact, Volt's unique advanced design has helped establish a new category — Extended-Range Electric Vehicles or E-REVs. Basically, an electric motor would drive the vehicle at all times. So you'll be accelerating, driving on the highway, going uphill — all the normal driving requirements — propelled by electric power. A small gasoline engine and a generator would kick in when the battery power is depleted after driving up to 40 miles. The gas engine and generator then produce all the electricity needed to keep driving for hundreds of miles. It's this “range-extending” technology that makes Volt so unique. Think of Volt as an electric car that can generate its own electricity, allowing you to continue efficiently without any worry of running out of power.

Because the engine drives a generator that will run at a constant speed, the power band can be optimized for maximum fuel efficiency and lower emissions. The engine will not fully charge the battery (this would be an inefficient use of gasoline). Rather, it will provide enough juice to keep the car going until it can be fully charged in a household outlet. This kind of advanced propulsion system means there are fewer demands on the engine, which can be sized, engineered and controlled to operate in a narrow range of rpm and at peak efficiency.


Because the engine drives a generator that will run at a constant speed, the power band can be optimized for maximum fuel efficiency and lower emissions. The engine will not fully charge the battery (this would be an inefficient use of gasoline). Rather, it will provide enough juice to keep the car going until it can be fully charged in a household outlet. This kind of advanced propulsion system means there are fewer demands on the engine, which can be sized, engineered and controlled to operate in a narrow range of rpm and at peak efficiency.

Extraordinary technological breakthroughs have helped Volt capture the public's imagination. But the real story of the Volt is how all that fuel-saving, emissions-reducing technology will help fundamentally change the way we drive, without affecting the driving patterns and habits that we're used to.

from : http://www.chevrolet.com/electriccar/articles/index.jsp?id=3

© yankandpaste®

No comments: