GM E-Flex platform
Encyclopedia
Voltec, formerly known as E-Flex, is a General Motors
powertrain
released in November 2010. The Voltec architecture is primarily a plug-in capable, battery-dominant electric vehicle with additional fossil fuel powered series and parallel hybrid capabilities. Voltec vehicles are all electrically driven, feature common drivetrain components, and will be able to create electricity on board using either a fuel cell or a gasoline motor to generate electricity. Regenerative braking also contributes to the on-board electricity generation.
Voltec is a portmanteau word
from Volt
and Vortec
concept vehicle that appeared in the North American International Auto Show
which introduced the E-Flex drive system as an attempt to standardize many components of possible future electrically propelled vehicles, and to allow multiple interchangeable electricity-generating systems. The initial design as envisioned in the Volt combines an electric motor and 16 kW·h (57.6 MJ) lithium-ion battery plug-in system with a small engine (1.0 liter) powered by gasoline
linked to a 53 kW generator. The initial production Volt will be propelled by an electric motor
with a peak output of 120 kW. Ordinarily, the Volt would be charged while at home overnight (plug-in hybrid-mode) through a charging port. A full charge reportedly takes 10 hours from a standard North American 120 V
, 15 A
household outlet, or 4 hours from a 240 V 15 A SAE J1772 electrical vehicle supply.
Since the electrical drivetrain is not affected by the method used to charge the batteries, several options could be available for acting as an electrical power source. The primary configuration specified in the Volt promotional literature uses a turbocharged
1.0-liter engine with three cylinders, a flex-fuel engine capable of running gasoline
or E85
(85% ethanol
, 15% gasoline).
Other engine-driven power options would be a pure ethanol (E100) engine, a diesel engine
capable of running biodiesel
fuel, or even a hydrogen fuel cell, once that technology becomes practical. (The Ford Airstream
concept, which debuted at the same show, uses a fuel cell plug-in hybrid design.)
Another power-source option, one that does not rely on an internal-combustion engine at all, was demonstrated in the Volt fuel cell
concept vehicle, which appeared at the 2007 Shanghai Auto Show. Due to the high cost of fuel cells compared to newer lower cost lithium batteries, General Motors has publicly suggested that the Volt will not be using fuel cells in any near term production vehicles.
The general layout of the initial production platform is considered by some to be a plug-in series hybrid design since mechanical power initially drives the generator, which in turn charges the battery pack. Power is then drained from the batteries to run the electrical motors which move the vehicle. The internal combustion engine does not have any direct mechanical linkage to the wheels (unlike current hybrid vehicles such as the Toyota Prius
), and can run at a constant speed for both optimal efficiency and mechanical simplicity (i.e., there is no need for a multi-valve, multi- or variable-cam design). The Voltec, like the Prius, uses a planetary gearset to couple power from two sources to the wheels. Unlike the Prius, the Voltec only rarely drives the wheels with mechanical assist from the engine. The Voltec could therefore be considered a power-split hybrid.
The lithium-ion battery in the initial Voltec production vehicle is kept in a state-of-charge (SOC)
range of between 30% and 80%, with the on-board generator starting to recharge the battery at the 30% level.
GM has decided on a new descriptive terminology distinct from calling it a hybrid. They are calling the Volt an E-REV, for "extended-range electric vehicle". This is in part justified since there is no direct mechanical linkage between the petrol engine and the wheels. At high demand in charge sustaining mode, both the electrical motor and the motor generator simultaneously drive the wheels. In this mode, the internal combustion engine is connected to the planetary transmission through the motor generator.
GM chose its Global Delta II compact vehicle architecture for its first Voltec application, the Chevrolet Volt
. Production began in November 2010 with the first Chevrolet Volt
s delivered to retails customers in December 2010
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
powertrain
Powertrain
In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive...
released in November 2010. The Voltec architecture is primarily a plug-in capable, battery-dominant electric vehicle with additional fossil fuel powered series and parallel hybrid capabilities. Voltec vehicles are all electrically driven, feature common drivetrain components, and will be able to create electricity on board using either a fuel cell or a gasoline motor to generate electricity. Regenerative braking also contributes to the on-board electricity generation.
Voltec is a portmanteau word
Portmanteau word
A portmanteau or portmanteau word is a blend of two words or morphemes into one new word. A portmanteau word typically combines both sounds and meanings, as in smog, coined by blending smoke and fog. More generally, it may refer to any term or phrase that combines two or more meanings...
from Volt
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
and Vortec
Drivetrain
The Voltec drivetrain was initially demonstrated as E-Flex in the 2007 Chevrolet VoltChevrolet Volt
The Chevrolet Volt is a plug-in hybrid electric vehicle manufactured by General Motors. The Volt has been on sale in the U.S. market since mid-December 2010, and is the most fuel-efficient compact car sold in the United States, as rated by the United States Environmental Protection Agency...
concept vehicle that appeared in the North American International Auto Show
North American International Auto Show
The North American International Auto Show is an annual auto show held in Detroit, Michigan at Cobo Center, usually in January. It is among the largest auto shows in North America.-History:...
which introduced the E-Flex drive system as an attempt to standardize many components of possible future electrically propelled vehicles, and to allow multiple interchangeable electricity-generating systems. The initial design as envisioned in the Volt combines an electric motor and 16 kW·h (57.6 MJ) lithium-ion battery plug-in system with a small engine (1.0 liter) powered by gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
linked to a 53 kW generator. The initial production Volt will be propelled by an electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
with a peak output of 120 kW. Ordinarily, the Volt would be charged while at home overnight (plug-in hybrid-mode) through a charging port. A full charge reportedly takes 10 hours from a standard North American 120 V
Volt
The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...
, 15 A
Ampere
The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...
household outlet, or 4 hours from a 240 V 15 A SAE J1772 electrical vehicle supply.
Since the electrical drivetrain is not affected by the method used to charge the batteries, several options could be available for acting as an electrical power source. The primary configuration specified in the Volt promotional literature uses a turbocharged
Turbocharger
A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...
1.0-liter engine with three cylinders, a flex-fuel engine capable of running gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
or E85
E85
E85 is an abbreviation for an ethanol fuel blend of up to 85% denatured ethanol fuel and gasoline or other hydrocarbon by volume. E85 is commonly used by flex-fuel vehicles in the US, Canada, and Europe. Some of the benefits of E85 over conventional gasoline powered vehicles include the potential...
(85% ethanol
Ethanol fuel
Ethanol fuel is ethanol , the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion litres...
, 15% gasoline).
Other engine-driven power options would be a pure ethanol (E100) engine, a diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
capable of running biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....
fuel, or even a hydrogen fuel cell, once that technology becomes practical. (The Ford Airstream
Ford Airstream
The Ford Airstream is a new concept car which made its debut at the 2007 North American International Auto Show in Detroit, Michigan. The Ford Airstream is a retro-futuristic crossover SUV that was inspired by the classic Airstream recreational vehicle trailers built since the 1930s...
concept, which debuted at the same show, uses a fuel cell plug-in hybrid design.)
Another power-source option, one that does not rely on an internal-combustion engine at all, was demonstrated in the Volt fuel cell
Fuel cell
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...
concept vehicle, which appeared at the 2007 Shanghai Auto Show. Due to the high cost of fuel cells compared to newer lower cost lithium batteries, General Motors has publicly suggested that the Volt will not be using fuel cells in any near term production vehicles.
The general layout of the initial production platform is considered by some to be a plug-in series hybrid design since mechanical power initially drives the generator, which in turn charges the battery pack. Power is then drained from the batteries to run the electrical motors which move the vehicle. The internal combustion engine does not have any direct mechanical linkage to the wheels (unlike current hybrid vehicles such as the Toyota Prius
Toyota Prius
The Toyota Prius is a full hybrid electric mid-size hatchback, formerly a compact sedan developed and manufactured by the Toyota Motor Corporation...
), and can run at a constant speed for both optimal efficiency and mechanical simplicity (i.e., there is no need for a multi-valve, multi- or variable-cam design). The Voltec, like the Prius, uses a planetary gearset to couple power from two sources to the wheels. Unlike the Prius, the Voltec only rarely drives the wheels with mechanical assist from the engine. The Voltec could therefore be considered a power-split hybrid.
The lithium-ion battery in the initial Voltec production vehicle is kept in a state-of-charge (SOC)
State of charge
State of charge is the equivalent of a fuel gauge for the battery pack in a battery electric vehicle , hybrid vehicle , or plug-in hybrid electric vehicle...
range of between 30% and 80%, with the on-board generator starting to recharge the battery at the 30% level.
GM has decided on a new descriptive terminology distinct from calling it a hybrid. They are calling the Volt an E-REV, for "extended-range electric vehicle". This is in part justified since there is no direct mechanical linkage between the petrol engine and the wheels. At high demand in charge sustaining mode, both the electrical motor and the motor generator simultaneously drive the wheels. In this mode, the internal combustion engine is connected to the planetary transmission through the motor generator.
Production vehicles
- Chevrolet VoltChevrolet VoltThe Chevrolet Volt is a plug-in hybrid electric vehicle manufactured by General Motors. The Volt has been on sale in the U.S. market since mid-December 2010, and is the most fuel-efficient compact car sold in the United States, as rated by the United States Environmental Protection Agency...
GM chose its Global Delta II compact vehicle architecture for its first Voltec application, the Chevrolet Volt
Chevrolet Volt
The Chevrolet Volt is a plug-in hybrid electric vehicle manufactured by General Motors. The Volt has been on sale in the U.S. market since mid-December 2010, and is the most fuel-efficient compact car sold in the United States, as rated by the United States Environmental Protection Agency...
. Production began in November 2010 with the first Chevrolet Volt
Chevrolet Volt
The Chevrolet Volt is a plug-in hybrid electric vehicle manufactured by General Motors. The Volt has been on sale in the U.S. market since mid-December 2010, and is the most fuel-efficient compact car sold in the United States, as rated by the United States Environmental Protection Agency...
s delivered to retails customers in December 2010
Concept vehicles
- Cadillac ProvoqCadillac ProvoqThe Cadillac Provoq is a concept luxury crossover vehicle revealed on 8 January 2008, and manufactured by General Motors. It was introduced at the 2008 Consumer Electronics Show in Las Vegas, NV and is powered by the plug-in hybrid technology first shown in the Chevrolet Volt...
- Saturn Flextreme
- Opel FlextremeOpel FlextremeThe Opel Flextreme is a diesel plug-in hybrid concept car created by Opel.It is based on the same GM E-Flex series hybrid platform used in the Chevy Volt, but using a diesel rather than gasoline engine. It can travel on its lithium-ion battery before a small diesel engine starts charging the battery...
- Cadillac ConverjCadillac ConverjThe Cadillac Converj is a plug-in hybrid concept car developed by General Motors, to be mass produced as the Cadillac ELR. It was first shown at the 2009 North American International Auto Show in Detroit and made its West Coast debut at the 2009 Orange County Auto Show.Incorporating the propulsion...
- Opel Ampera