FAW Proposes Parallel Extended-Range EV

The Chinese auto maker says its new electrified car stacks up favorably against the series-parallel Chevy Volt EREV and Audi A1 e-tron’s serial EREV system.

July 18, 2012

3 Min Read
FAW says cities such as Changchun well suited for lowspeed EREVs
FAW says cities such as Changchun well suited for low-speed EREVs.

CHANGCHUN, China – FAW Group is developing its own parallel extended-range electric vehicle intended for low-speed applications in congested cities, such as Beijing or Shanghai, but it is unclear whether the auto maker will bring the car to market.

The concept is nearly finished after 10 years of work and now is undergoing additional engineering, Li Jun, president of China FAW research and development, tells some 500 attendees at this week’s Advanced Vehicle Technologies and Integration conference here.

Li says the innovation lies in the parallel powertrain configuration: At low speeds, the concept runs on either electricity or energy from the internal-combustion engine, but at higher speeds both systems work together for maximum efficiency, until the battery is depleted.

Power comes from a new 0.67L 2-cyl. gasoline direct-injection turbocharged engine based on two engines already in production in Tianjin, a 1.0L 3-cyl. and a 1.2L 4-cyl. Current production for the two engines is 200,000 units annually, Li tells WardsAuto.

The 0.67L powerplant acts as an auxiliary energy supply similar to the 1.4L gasoline engine that generates power for the Chevrolet Volt EREV.

FAW uses a 9 kWh lithium-ion LG Chem battery, compared with the Volt’s 16 kWh unit, also supplied by LG Chem. The battery lies under the floor of the FAW car and weighs 231 lbs. (105 kg). Range is 37 miles (60 km), comparable with that of the Volt. Li says FAW’s research finds 37 miles of range to be more than adequate for most Chinese drivers.

FAW’s concept is able to compete with the Volt in terms of electric range because the Chinese vehicle will be smaller and lighter, Li says. The concept, a front-wheel-drive A-segment city car, has a curb weight of 2,425 lbs. (1,100 kg), compared with the Volt’s 3,781 lbs. (1,715 kg).

When the battery runs out of juice, the 0.67L 2-cyl. engine takes over, producing 56 hp at 5,000 rpm and 68 lb.-ft. (92 Nm) of torque at 5,000 rpm. The bore measures 2.83 ins. (72 mm) and the stroke is 3.18 ins. (81 mm).

A 12 kW generator works in tandem with a 360V traction motor and a 2-speed transmission to turn the wheels when maximum torque is required or when the battery is empty.

The FAW concept provides a mechanical connection between the engine and wheels. A downside of this configuration: The engine and wheels are never decoupled.

With a full tank of gas, the FAW concept has a combined range of more than 249 miles (400 km), Li says. The vehicle’s top speed is 99 mph (160 km/h), and acceleration from 0 to 62 mph (100 km/h) is 11 seconds.

FAW refers to the concept as its “1 L/100 km Fuel Consumption Car,” but Li says drivers may be able to achieve combined energy consumption that actually is lower.

In developing the technology, Li says FAW benchmarked the series-parallel EREV system in the Volt and the Audi A1 e-tron’s serial EREV system. The A1 e-tron, which is undergoing fleet testing in Munich, has a rear-mounted rotary engine as a range-extender.

FAW concluded its parallel configuration has “an absolute advantage in driving range, performance and fuel economy” over both the Audi and General Motors systems, but that the e-tron package has a cost advantage, Li says.

As part of the benchmarking, FAW paired its EREV system with a 1.4L engine similar to GM’s and achieved similar power, as well as weight reduction and lower cost when compared with the Volt.

Li says the hybrid powertrain adds RMB 54,700 ($8,581) to the cost when compared with a vehicle powered by a conventional gasoline engine. Most of that cost is associated with the battery.

Overall, he says the FAW concept is far more cost efficient than an all-electric vehicle. Even without a government subsidy, he says the buyer of such a vehicle could pay off the additional cost within eight years.

Li says FAW developed the entire system. If the vehicle goes into production, the auto maker likely would purchase the traction motor in the beginning, but eventually could move that production in-house.

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