New Electric Motor Drives Renault PHEV Project

ROUEN, France – Renault is developing a plug-in hybrid-electric vehicle for the C-segment to attract customers who want more range than the 150 km (93 miles) offered by Renault’s battery-electric vehicles.

Most competitors have developed both an EV and a plug-in, says Jean-Pierre Fouquet, head of the PHEV project, at a symposium sponsored by the regional Moveo industry cluster, so Renault is planning to join the crowd.

The project still is at the research stage, says Fouquet, and the “Zero Emission on Demand” project is not yet accepted for production, although he expects a decision later this year.

Meanwhile, he says, Renault has filed 30 patents on its concept for a new electric motor for the PHEV integrated with a 3-speed transmission. Allowing for a government subsidy, he says, Renault could sell the car for about €20,000 ($27,000), the same as a Toyota Yaris Hybrid.

Renault and PSA Peugeot Citroen have been working together with suppliers on a project sponsored by France to develop cars that emit carbon dioxide at a rate of 50 g/km.

A slide prepared for the symposium by Moveo shows how a Peugeot 208 could reach 50 g/km with PSA’s Hybrid Air approach, while a Renault Clio with a plug-in hybrid powertrain could reach 30 g/km.

The French automotive press has reported widely Renault will show a Clio-sized PHEV concept at the Geneva auto show in March.

The target price for the Megane-size C-segment car in development likely will include the lithium-ion battery, says Fouquet.

With its four EVs, Renault is leasing the battery to customers, but most competitors are including the price of the battery in their hybrids and PHEVs, so Renault is considering doing the same.

“Today the two scenarios are being considered,” he says. “But we are going to arrive at price levels where this kind of battery would have a very low rental fee. The majority of competitors’ hybrids, including plug-in hybrids, propose to sell the battery.

“Offering a selling price for a PHEV in a segment where the competition has an HEV… is a strong move for Renault, in terms of concept and for Renault’s goal of ‘mobility accessible to everyone.’”

Before the car would come to market, he says, battery prices must drop significantly, and perhaps that will be the moment Renault switches from leasing batteries to selling them, “including for the electric vehicles.”

Fouquet says the 400V Li-ion battery in the PHEV – about one-third the size of the 22 kWh battery in the electric Zoe – would give customers a driving range of 19-25 miles (30-40 km) and a top speed of 75 mph (120 km/h) on battery alone.

He says the chemistry would be similar to that of the Li-ion batteries in the EVs, tuned to favor power over energy.

The gasoline engine would let owners drive anywhere there are gas stations, and the car would be rated on Europe’s NEDC driving cycle at less than 50 g/km of CO2, or 111 mpg (2.1 L/100 km). The car would carry five passengers, like the current Megane in the C-segment.

Today, says Renault, the only hybrids costing about €20,000 in Europe are the Yaris and Honda Jazz, both competing in the B-segment, and neither one a plug-in.

Renault says its goal is a vehicle for which the total cost of ownership is less than that of a diesel in the same segment with an automatic transmission. Renault sells its cheapest Megane diesel with a dual-clutch transmission for €26,500 ($36,047).

Fouquet does not say how much of a government incentive Renault would expect for its PHEV should it arrive on the market. But today, electric vehicles get a €6,300 ($8,569) discount and PHEVs get E4,000 ($5,442).

New Electric Motor, Clutchless Transmission Keys

Fouquet says Renault’s idea for a cheaper plug-in hybrid relies on a new electric motor, a new 3-speed clutchless transmission and the inverter/charger and powertrain controller from the EV program.

“We have the simplicity of the concept around a motor, an ICE engine, a transmission and a system of actuators,” he says. “We put the intelligence in the software. Hardware is expensive.”

He gave an example of a car parked for several weeks at an airport in which the battery slowly discharges below the level required to start the car.

“Contrary to the competitors’ complex systems, where there are generally two electric motors, one for traction and one generator, today we have only one electric motor,” says Fouquet.

“However, we have introduced in the concept a function called Smart Charge. The internal-combustion engine will start for several minutes, recharging the battery. As soon as we have reached the charge needed, (the electric motor can take over). We don’t have a generator, but we have the intelligence of the system, which is much less costly than another component.”

The PHEV motor will use permanent magnets with axial or radial flow, he says, producing 60 kW (80 hp) and 100 Nm (74 lb.-ft.) of torque.

Software will control nine different driving situations, from all electric to all internal- combustion, passing through the three gears of the transmission. The motor replaces the clutch by handling torque to the wheels while the gears are shifting.

Fouquet says shifts are as good as those on Renault’s DCT already on the market. He says the automatic nature of the transmission, and its low price, will help Renault in Asian markets, and “the internationalization of the concept is important.”

Fouquet says the vehicle will accelerate better than a Megane dCi 110 with a 6-speed manual transmission, thanks to boost from the electric motor. The diesel would take more than 7 seconds to accelerate from 31-50 mph (50 to 80 km/h) in fourth gear, and the PHEV is calculated to do it in about 4 seconds.

A 50 g/km PHEV would put Renault even further ahead in terms of meeting future fuel- efficiency norms. Europe is targeting a fleet average for all automakers of 95 g/km by 2021, and discussions are proceeding in Brussels for a subsequent goal of 75 g/km.

Last June, says Fouquet, Renault was the most efficient brand in Europe with a fleet rating of 115.9 g/km. Sales of Renault’s EVs were worth 5 g/km, he says, which pushed Renault ahead of Peugeot (117.8 g/km) and Toyota (117.2).