Volvo Concepts Show Three Approaches to Extended Range Electric Vehicles
Extended Range Electrical Vehicles (EREVs) offer most of the advantages of battery electric vehicles. EREVs also eliminate one of their biggest disadvantages – ‘range anxiety,’ or the fear of being stranded if batteries are completely discharged with nowhere to recharge, Following in the footsteps of the Chevy Volt, the first EREV on the market, other automakers are developing EREVs as well. This includes Volvo, which has shown three different EREV concepts. All three use a small three-cylinder flex fuel engine that can operate on gasoline and E85 ethanol. Testing of these concepts will begin in the first quarter of 2012.
Technical Concept I is series-hybrid with range extension much like the Chevy Volt. The gasoline engine is located beneath the rear compartment floor in a C30 Electric coupe, which is now in limited volume production. The 60 horsepower engine drives a 40 kilowatt generator that either supplies the 114 horsepower (82 kilowatt) peak electric motor driving the front wheels or charges the battery pack. The latter increases all-electric range beyond the 68 mile range provided by the battery pack without recharging. With a 10.5 gallon fuel tank, range extension gives this version an additional 621 miles, for a total 688 mile driving range.
Technical Concept II features a parallel hybrid configuration using the C30 Electric. A more powerful 190 horsepower, turbocharged three-cylinder engine primarily drives the rear wheels via a six-speed automatic transmission for long distance highway travel. The engine and transmission are positioned at the rear. The 114 horsepower electric motor drives the front wheels to provide four-wheel-drive. The two propulsion sources provide over 300 horsepower, sufficient to accelerate the car to 100 62 mph in seconds. The 40 kilowatt generator keeps the battery charged to give the car increased range beyond the 47 miles provided by the battery pack alone, up to as much as 728 miles.
Technical Concept III uses the larger V60 Sportwagen so the entire drive package fits under the hood. The battery pack is located beneath the rear floor. This parallel hybrid is similar to Technical Concept II in that it uses the 111 horsepower electric motor supplemented by the 190 horsepower, supercharged three-cylinder turbo engine. Power from both the motor and engine drive the front wheels via a two-speed automatic transmission. This version can travel up to 31 miles at up to 31 mph on battery power alone. The combustion engine starts at higher speeds and charges the battery pack when its charge drops below a predetermined level. The Concept III has a total range by more than 621 miles.