Auto-electrification

Ford is one of many car-makers planning to target the growing market for hybrid and all-electric cars. E&T finds out how it is getting on.

Petrol-free passenger cars are no longer the sole province of small specialist manufacturers. The large car-makers too are forging ahead with electrification strategies that could see a larger slice of road traffic going green.

One of the more aggressive developers is Ford, which has test vehicles on the road as part of its plan to bring electrified vehicles to market over the next four years. Although not alone in its drive to capture this potentially valuable market, Ford's strategy and product range reflects the market sentiments; primarily that there is no silver bullet. To be successful requires a portfolio of technologies.

The Ford strategy calls for the introduction of new hybrids, a Plug-in Hybrid Electric Vehicle (PHEV) and Battery Electric Vehicles (BEVs) based on two new global product platforms. The plan calls for in 2011 a pure BEV - using lithium-ion battery technology - as a passenger car in North America.

As Ford and its partner Magna International hustle to bring this new BEV to market, test vehicles have been on the road for more than six months, racking up thousands of miles of testing and evaluation.

Why hasn't Ford's BEV test vehicle been spotted on public roadways? Because it looks just like a 2009 Ford Focus. Under the skin of the test vehicle is a new all-electric powertrain that will go into Ford's new-generation C-sized global vehicle platform. The BEV will first be introduced in North America, with the potential to migrate to the European and Asia Pacific markets down the road. Test mules using current model bodies are often used by automotive engineers to prove out technology and conceal future technology from prying eyes.

Ford's path to the complicated future of vehicle electrification is simple: build products that customers want, build them on global platforms, and build them affordably. The results, in terms of significantly reduced energy consumption and CO2 emissions, will follow.

Electrification for sustainability

"Our electrification plan is about executing a key piece of the Ford Blueprint for Sustainability," says Derrick Kuzak, Ford group vice president, global product development. "That's the strategic engine driving our approach to advanced technology vehicles.

"We're building on our near-term momentum with technologies such as EcoBoost, increased hybrid production and now electrification. These are all actions that will make a difference and doing it globally - leveraging platforms, organisations and talent."

Ford, however, recognises that the challenge of vehicle electrification is anything but simple. Future technologies, such as BEV and PHEV systems, are still in their development stage. New-generation electric vehicles will depend on advances in lithium-ion battery technology, commonly used in consumer electronics. Work is focusing on making lithium-ion battery packs, which are still too expensive for mass-market cars, viable for the more intensive requirements of the automotive environment.

Electrification also brings with it new stakeholders who are key to the successful transformation of personal vehicles from their dependence on traditional internal combustion engines to more sophisticated, fuel saving, reduced-emission powerplants of the future. Electrical utilities are foremost among these stakeholders, as new-generation electrical vehicles will need to be charged from the power grid.

"We've explored and tested many different technologies for the future and we're convinced that electrification is the next major shift in the light-duty transport sector," says Nancy Gioia, Ford's director of sustained mobility technology. "That's why this is a significant part of our Blueprint for Sustainability.

"We always start with the customer. We have our full hybrid on the road today and we are adding another vehicle, and they work great for short or long distance drivers. Customers have various needs, and may not have access to a plug to recharge the vehicle.

"Then we come to plug-in hybrid, which will launch in 2012. For drivers with a garage, it will provide up to 30 equivalent electric miles. It is really targeted at folks who do more city driving or urban driving. Their average daily drive would be 30 miles, which is 50 per cent of the customers in urban areas. It is a blended hybrid so if they have to get on the highway and do hundreds of miles, the car operates as a regular hybrid and doesn't require a plug.

"For battery-electric vehicles we will have a Focus-sized vehicle in 2011 that goes up to a 100-mile range. These are for customers who have very repeatable routes and they may have an additional vehicle for long distance. For many urban drivers, this is perfectly acceptable. It re-charges in about five or six hours, but that does require a 220V outlet. You can re-charge at 110V, but then it would take 11-12 hours.

"Looking at the battery cost, which is one of the huge drivers, we want affordable solutions for our customers and we think that you need to have this technology, along with efficient diesel for European customers in particular. We still see diesel as dominating Europe because of the policy and fuel prices.

"As a company we also need efficient petrol solutions such as EcoBoost which is the turbo fuel-injection engine downsizing in combination with six-speed transmission and other vehicle efficiencies. There is no one fuel that does it all for customers - there are different performance characteristics in these vehicles in terms of range and affordability, so we wanted to make sure we offered a fleet of products."

Affordable electric

Ford is linking up with high-tech partners to bring electric-powered vehicles to market quickly and affordably. Earlier this year the company announced a collaboration with Magna International to bring a new lithium-ion battery-powered small car to market in North America in 2011.

Ford already has other collaborations and partnerships to accelerate the commercialisation of electrified vehicles. Southern California Edison and the Electric Power Research Institute are currently road testing a fleet of Ford Escape Hybrid Plug-ins. Work with the utility industry partners is focused on understanding customer usage and the interconnectivity of vehicles with the electric grid.

"We formed the Ford Plug-in Project and started with Southern California Edison in July 2007 and delivered the first vehicle to them in December 2007," Gioia says. "EPRI [the Electrical Power Research Institute] does a great deal of research on what is required for the grid and standards and things like this. They joined in March 2008 and we just announced in Washington DC seven additional utility partners.

"The US Department of Energy joined the collaboration in June 2008 with a $10m grant. We have been on a very aggressive roll to have government, utilities and research organisations that associate with utility to work with us so we define standards, protocol, interface communications and really think through how these two industries, utilities and automotive, will now interface with the common customer around this new fuel called electricity.

"The more seamless we make that for our customers, we lower that barrier of new technology acceptance. In the meantime, we are also understanding how this can be a sustainable business model for all of the partners.

"One of the reasons that we have taken out a very strong collaborative approach is to achieve a quick speed to market," Gioia explains. "It has been very strategic, we have sought out very capable competent partners so we can share the investment, reduce time to market, reduce risk and quickly get product out there that leverages our global platform which again helps our affordability.

"Right now we are looking at a global C-sized vehicle platform and our global C/D-sized platform: the C would be like a Focus and the C/D would be like the Mondeo. That represents for us in global sales four million units a year in those two segments, which are the largest segments in the world."

Gioia is quick to explain that the relationship with Magna is a collaboration, not a joint venture. Magna will be simply supplying components and subsystems for the battery electric vehicle.

"They will, for example, be doing the gearbox for us and the electronics control," she says. "They will be the battery integrator, but they are not producing the battery cell; that will be coming from a supplier.

"The electric motors and machines are going to be Magna's supply responsibility whether they choose to make or purchase those from somebody else. What we will be working with Magna is providing the brunt of the specific components, which is what Magna is incredibly good at.

"They are the largest global automotive component supplier. They are combining their talents of their electronics group, their powertrain group to bring forward the fleet of components and sub system and system levels as needed.

"Ford will be doing the vehicle integration of those components into our vehicles and are responsible for the overall vehicle performance, safety, crash structure, the DNA of the car, the ride, handling, steering, braking; all of those will be Ford's responsibility. On top of that, the software that takes the battery electric controls and integrates them into the total vehicle control system is Ford's responsibility."

The BEV test vehicle

The BEV test vehicle does not have an internal combustion engine. Instead, it is powered by an electric motor and high-voltage lithium-ion battery cells. After an overnight charge, it's ready for a range of more than 80 miles.

Lithium-ion is the latest in electric vehicle battery technology. While the chemistry is similar to the batteries used in consumer goods like laptops and mobile phones, the demands of powering a vehicle are different enough to require significantly more intensive technology development. Lithium-ion batteries are lighter and more power efficient than the nickel metal hydride batteries used in today's hybrid electric vehicles.

The BEV test vehicle features a battery pack with seven modules of 14 lithium-ion cells, giving the vehicle 23 kilowatt (kw) hours of usable energy. The battery arrays are packaged in the boot and underseat space.

In the engine compartment, the battery power goes to work. A 100kw permanent-magnet, chassis-mounted electric traction motor operates on three-phase alternating current (AC). A sophisticated motor controller and inverter convert the battery's direct current to AC.

The powertrain, including the motor and gearbox, are packaged under the bonnet just like a petrol powertrain, using existing powertrain mounts. The test unit also incorporates key components from Ford's proven hybrid technology, including the electric climate control system. The high-voltage air-conditioning compressor is the same as the one in the new 2010 Ford Fusion Hybrid.

Battery of challenges

Whichever car-maker you talk to, they consider battery technology the prime challenge that needs to be overcome if electric cars are to ever become more than a niche application.

"It is all about the batteries," Gioia confirms. Today Ford uses nickel metal hydride cells in its hybrids. "One of the biggest challenges is energy storage in a battery cell," she continues. "Whether it is the nickel metal hydride or lithium, we have now got to the point, based on testing, where we are quite confident on that durability.

"For our hybrids and plug-in hybrids, ten years and 150,000 miles is not an issue at all. For the battery, electrically we need targets of 2,000-3,000 discharge cycles to have that function, so we are confident with the chemistry with the control systems and knowledge that we have, durability and life of the cell is not an issue.

"We are also very confident in the safety performance. We understand that in the past there was a lot of concern over lithium-ion from the computer industry and the safety performance of those cells. We incorporate all of the lessons learned. We run at much higher energy levels, but we understand the cell design, the chemistry performance, the energy management and the safety management systems.

"We think that we have overcome whatever issues there were over safety, durability and reliability. We design that in. The challenge is cost and the cost is substantial.

"What we have tried to do is make sure we size the battery as small as possible so that every ounce of that energy is used by each of the applications. Whether it is the battery electrics, plug-in hybrid or full hybrid, we try to make sure that every ounce or pound of energy is fully used by the consumer every day, because that is the most efficient use of a high-cost asset and, frankly, it is the most efficient use of energy."

Internal combustion lives on...

But all this developing into electrifying cars does not mean the end of the internal combustion engine. "We still see, for example, heavy trucks towing load-carrying vehicles much better served by EcoBoost and other alternatives, because electric machines and motors don't work terribly well with the high towing of those types of vehicles," Gioia says.

"We also see some customers who simply don't have access to electricity and they may be looking for petrol or diesel solutions. So I think we still see it as a fleet of products.

"We think that the internal combustion engine will be around for quite a bit of time. Oil as an energy source and fuel is still the most efficient for the transfer of energy to drive the wheel. It has the best percentage of energy content that can be transferred to moving the wheel. We are looking at what is right in that field to total solution that is affordable."

Quite how important the electric car is to Ford's future success is difficult to judge, but Gioia is clear that it sees it as a growth area. "From today the hybrid market, medium and full, in North America is about 3 per cent; globally it is about 1.5 per cent. It has taken eight years to get there so what we see is that electrification is going to continue to grow to become part of the fleet moving forward.

"We don't expect it to suddenly become the dominant source for many years, but we do very much see it as a credible and growing part."

1. Motor controller and converter

The motor controller monitors the motor's position, speed, power consumption and temperature. Using this information and the throttle command by the driver, the motor controller and inverter convert the DC voltage supplied by the battery to three precisely timed signals used to drive the motor.

2. High voltage electric HVAC compressor

The high voltage air conditioning system is specifically designed for hybrid vehicle applications, drawing electrical energy directly from the main battery pack. An inverter is included in the compressor.

3. Electric water pump

The electric drive water pump circulates coolant for the traction motor, inverters, battery and heater.

4. Traction motor

The traction motor performs the conversion between electrical and mechanical power. Electric motors also have efficiencies three times higher than that of a standard gasoline engine, minimising energy loss and heat generation.

5. Electric power steering

Electro-hydraulic steering pump was installed to assist a returned steering rack. A production vehicle would be designed with electric power steering.

6. Gearbox

The transmission has the same role as in a conventional vehicle; however, it has different design considerations due to the higher RPM range available from the electric motor and increased emphasis on efficient and silent operation. The transmission is a single-speed unit with 5.4:1 reduction.

7. Modular powertrain cradle

A structure for monitoring all engine compartment EV components and providing isolation from the vehicle body through traditional engine mounts.

8. Electric vacuum pump

The vacuum pump supplies vacuum to the brake system for power assist.

9. High-voltage PTC electric coolant heater and controller

Heating systems are specifically designed for hybrid vehicle applications. Energy efficient PTC technology is used to heat the coolant that circulates to the passenger car heater. Heat also may be circulated to the battery.

10. Vehicle control unit

The VCU communicates with the driver as well as each individual vehicle system to monitor and control the vehicle according to the algorithms developed by the vehicle integration team. The VCU manages the different energy sources available and the mechanical power being delivered to the wheels to maximise range.

11. Battery pack and battery cells

The battery pack is made up of seven battery modules of 14 cells, 98 cells total for 23kWh of power. The batteries are air cooled using existing vehicle cabin air. The pack includes an electronic monitoring system known as the BMS that manages temperature and state of charge of each of the cells.

12. AC charger

Power electronics are used to convert the off-vehicle AC source from the electrical grid to the DC voltage required by the battery, thus charging the battery to its full state of charge in approximately eight hours based on a 110v source. The current charger is air cooled. The production design should be water cooled and be able to accommodate both 110 and 220 voltage sources.

13. DC-DC converter

A DC-DC converter allows the vehicle's main battery pack to charge the on-board 12V battery, which powers the vehicle's various accessories, headlights, etc.

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