January 10, 2001
2003 Explorer to offer electric assist
Ford Motor Company’s next-generation Explorer will have a new high voltage electrical system and a technology that automatically shuts the engine off when the vehicle is stopped.
Known in the industry as an integrated starter-generator or ISG, this start-stop engine technology will debut in the Ford Explorer soon after the Escape hybrid electric vehicle (HEV) in 2003. But unlike the Escape HEV – a full hybrid that uses an electric motor for propulsion and a 4-cylinder gasoline engine – the ISG 42-volt Explorer will rely on an efficient 6-cylinder gasoline engine with electric assist. The integrated starter-generator, as its name applies, replaces both the conventional starter and alternator and integrates starting and generating in a single electric machine.
The integrated starter-generator will allow the engine to automatically shut off when the Explorer is stopped, such as at a traffic signal, and then immediately start again when the need for power is anticipated. The transition from stop to start will be completely transparent to the driver. This start-stop feature will help the Explorer achieve fuel economy numbers unheard of in a vehicle that provides the room, off-road toughness and power that America’s best-selling SUV delivers.
This start-stop feature debuted in Ford Motor Company’s P2000 HEV concept car and makes its first production application debut on the Escape HEV, a concept of which was shown last week at the Los Angeles International Auto Show. The Escape HEV will deliver about 40 miles per gallon in urban driving, yet deliver acceleration performance similar to an Escape equipped with a V-6 engine.
“The fuel-efficient technology in the future Explorer will continue our commitment to our customers and to society to develop the most capable and advanced SUVs on the planet,” said Gurminder Bedi, vice president – Ford Truck.
“The fuel economy gains we will achieve with this technology will set new standards for SUVs without sacrificing the capabilities customers expect.”
Coupled with this ISG system on the Explorer will be a regenerative braking system and a more powerful electrical system that delivers 42 volts rather than the current 12 volts. The regenerative braking system captures energy generated from the braking system to help recharge the vehicle’s 42-volt battery, which in turn provides the engine with a slight acceleration boost at startup. A smaller 12-volt battery, roughly the size of a motorcycle battery, will be used to operate standby items such as emergency flashers and radio.
Every year, automobiles require more electrical power for new vehicle features. Items such as electronically heated seats, entertainment and navigation systems are already reaching the upper limits of what the current 12-volt systems can handle. It is a system that was never designed to handle increasingly complex and demanding vehicle electrical requirements.
About one mile of wiring will go into the electronic intensive car of the near future. At 12-volts, that wiring has to be exceptionally thick to handle 3 kilowatts of current; and weight becomes an issue. With a 42-volt system, wiring bulk is reduced because higher-voltage lowers the electrical current, enabling narrower gauge wiring.
Ford Motor Company, like many in the industry, favours an initial dual-voltage system. The 42-volt core system would be supplemented by a 12-volt subsystem to run traditional low-voltage devises such as lamps and radios. This dual-voltage system eliminates the need for a costly redesign of the intricate, on-board electronic system used today, while retaining positive 12-volt attributes, such as the extension of filament life at lower voltages.
The 42-volt electrical system allows the company to more quickly satisfy customer demands for improved comfort and convenience items, including the ability to offer a 110-volt AC outlet that would allow customers to operate power tools from their vehicles. This high-voltage, high-powered electrical system also paves the way for advanced technology items such as energy-efficient electromechanical valvetrain actuation, electric superchargers and advanced active suspension systems. With electronically actuated valves, valve timing could be easily varied because it would be under computer control. The end result would be more horsepower from a smaller displacement engine that runs considerably cleaner.
The actions of all these subsystems are coordinated by a vehicle system controller that builds upon Ford Motor Company’s drive-by-wire experience gained through its Aston Martin programs, Jaguar S type and Ford’s diesel engine equipped F-Series, Transit, Mondeo and Focus. The use of an integrated starter-generator on Explorer helps support Ford Motor Company’s Cleaner, Safer, Sooner declaration to deliver vehicles that produce fewer emissions and improved fuel economy, far exceeding any regulatory requirements.