## Project FEVER to develop 48V through-the-road hybrid vehicle technology; SRM-based e-axle

##### 09 May 2016

Controlled Power Technologies, a developer of vehicle driveline electrification based on state-of-the-art switched-reluctance machines (SRMs), has partnered with Ricardo, Tata Motors European Technical Centre (TMETC) and Provector to develop a 48V through-the-road hybrid vehicle system and demonstrate it in a B-segment city car.

The Forty-Eight Volt Electrified Rear-axle (FEVER) project will apply CPT’s SpeedTorq technology to an ultra-lightweight rear axle module to significantly improve the fuel economy of the target car. The objective of the two-year project is to achieve a CO2 reduction of up to 15% over the regulatory cycle while offering significant savings (around $1,400) in manufacturing cost compared to a full HEV. The consortium has secured a funding award from Innovate UK, the UK’s innovation agency, which will contribute £1.8 million (US$2.6 million) of the total £3.4 million (US\$4.9 million) investment.

Integrating the electric motor within the rear axle will enable features such as low-speed electric driving or e-creep, as well as electrically assisted all-wheel drive, which will deliver additional significant savings over a typical representative city drive cycle. The technology will allow a carmaker to reduce the in-use carbon dioxide emissions of such vehicles by approximately 25g/km.

 CPT SpeedTorq ‘four quadrant’ switched-reluctance machine. Click to enlarge. Ricardo will develop a lightweight 48V rear axle module building on its work on the ULTRAN project. Click to enlarge.

CPT will lead the project and will be responsible for developing the electric motor and control system, and will support their integration into the rear axle module.

Provector has extensive experience in the control and management of advanced lead-carbon battery chemistry through projects such as ADEPT and its involvement with the Advanced Lead Acid Battery Consortium.

Ricardo’s key responsibilities within the project will be the design and analysis of the integrated 48V rear axle module, development of the supervisory vehicle control system, sub-system testing and project management support, building on its previous work on the ADEPT and ULTRAN projects.

TMETC will supply the base vehicles, develop the suspension solution, and provide support for the application of the technology and overall vehicle integration and testing.

This program will require a high level of project management and engineering cooperation, not least in the unique application of a low-voltage high-temperature-tolerant SRM, which has to be oil-cooled and packaged as efficiently as possible into a rear axle and suspension module complete with advanced lead-carbon battery.

—project director Peter Scanes, senior manager responsible for vehicle OEM mild hybrid programs at CPT

The mass roll-out of electrification within the urban transportation fleet will require new and innovative power architectures that provide a performance, value and emissions trade-off that will be attractive to potential customers. Ricardo believes that a 48V electrified rear axle offering through-the-road hybrid performance – including significant ‘engine-off’ operation – will be highly attractive for many market segments but particularly for those that predominate in urban transportation.

—Stephen Doyle, Ricardo hybrid and electronic systems product group head

The FEVER project will run for two years and will culminate in the development of two through-the-road, 48V electrified rear axle demonstration vehicles.

### Comments

I think this is a great idea - a lot of cars spend loads of time idling in heavy traffic or crawling through it (esecially outside my front door). If they could do this mostly engine-off, it would greatly reduce local pollution.
OK, it is not as ambitious as full hybrid or a BEV, but if it gets millions of cars upgraded, it will have a useful effect on local pollution and fuel consumption.
+ it would be great if you were stuck on snow or ice.

This solution obviously has benefits that the 'cheap' version of 48V micro-hybrid, i.e. a glorified starter motor/generator, does not.

But it is also a considerably larger modification to existing cars than changing parts in the engine room, or replace the gearbox with a slot-in 48V enabled (built in E-motor) gearbox.

Whichever variant of micro-hybrid is employed, reducing idling and slow-creep traffic has the potential to significantly reduce the burden of auto emissions in our cities. Peak-shaving of the engine load can also cut back on peak emission load cases.

It's too weak motor. With 48 Volt system you can get up to 15 kW peak power, continuous half of that or less.
Much better would be to use 2 such motors in some combination. Best in a 2 speed combination (say like in WrightSpeed).
Combine it with a 48 Volt rechargeable battery (up to 4 kWh).
It makes sense to have rechargeable battery just for AC in stop-n-go traffic in hot climate regions. AC compressor is a 3 kW or stronger motor.

I'd hope that the control system would allow you to "throttle" the rear motor in proportion, out of phase, or independently to the IC engine throttle.

CITY Proportional settings would have eco (default) and power modes for either normal mixed driving versus stop-go traffic.

HIGHWAY settings would use an out of phase control strategy to charge the batteries when the engine is working at peak efficiency and discharge the battery and apply power to the road when the engine is at high BSFC. Keeping the battery near it's optimum state of charge.

SPORT setting would allow you to independently control the rear wheels for maximum control.

It could even be sold as an aftermarket system for any vehicle. A fully integrated system could easily fit on a small classI trailer. A bluetooth controller plugged into the OBD port and a grip throttle on the park brake lever for the SPORT setting would constitute the integration into the vehicle operation. Use your phone to activate the app that controls the system and select the drive mode.

I should re-post this on half-bakery. LOL

To expand on my previous post on how this concept could be applied to the aftermarket-

Eliminate the rear axle module (referenced in this article) for the trailer idea and use two 15kW motors geared for optimum power efficiency at 55 MPH independently driving each independently suspended trailer wheel. The trailer should be mounted to the hitch with a 2-way swivel (heavily dampened to only allow relative motion during slow parking maneuvers) with load bars to increase pressure on the trailer tires. (vehicle and trailer weight distributed over all six wheels with a bias on the front steering wheels) Since each tire is able to spin at different speeds there is no issue with taking corners and skidding a tire. The e-trailer would have a narrow track similar to motorcycle trailer and a very short trailer tongue.
Newer vehicles with electronic steering would have a signal that could serve as an input to the push trailers integrated electronic stability control.

40hp (two motors) is enough to keep 5,000lb minivans at constant highway speed on a flat highway. Using an alternating pulse and coast method between the e-trailer and the vehicle engine would maximize fuel mileage during highway trips*. Placing a hitch ball mid-way between the wheels on top of the e-trailer would allow even small cars to safely tow 2500 lb trailers. The virtually extended vehicle wheelbase would also help in preventing lane-drift and sway where cross-winds are encountered. Parking lot maneuverability would only be affected slightly as the vehicle would essentially drive like a longer car as the two-way tongue swivels a few degrees to prevent the tires from skidding sideways in tight corners.

An e-trailer would negate the need to buy a truck just to haul your camper for vacations or a trailer for bulky items. With the money of a new full-size truck you could buy a nice new small car to meet your every-day usage and an e-powered trailer that you hook up only when you'd need the extra utility or want to make your car a virtual hybrid. Using the trailer would help to fill in power delivery, reducing the peak power required from the vehicle's IC engine which would save fuel in certain drive cycles. Insurance savings of the small car vs the truck and reduced fuel costs would pay you back even if the combined cost was greater than a full size truck.

*Set your regular cruise-control to a given speed then set the e-trailer to its HIGHWAY “cruise” setting. As it cycles the onboard battery state of charge between 50% and 80% it provides automatically alternating boost and resistance to the vehicle engine.

48 V battery is the best way to mitigate risk of high voltage in case of a car crash. It is why I have a close look at it. But it is not always necessary to get an electrical rear axle for driving traffic jam.
Explanation: With a double planetary gear system, electric power in a series-parallel system (Prius or Volt family) can be decreased to 10 KW which is compatible with 48 V voltage. As you know in this architecture, the electric chain has a Generator and a Motor. Reversing the Generator you can get 20 KW for pure electric propulsion in traffic Jam while the two machines can work as usual in other conditions.
Such device is described following link: http://contest.techbriefs.com/2016/entries/automotive-transportation/6289

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