Electric Cars Charged While Driving

Electric cars charge themselves while driving through magnetic coils in the road. Such wireless charging units are already available. However, up to now, charging by induction only works when both objects are stationary. In order for the alternating magnetic field to generate current in the receiver coil, the frequency of both coils must be exactly matched. If the distance or angle change, the charging power is immediately reduced or even completely broken.

Shanhui Fan, Stanford University, CA, USA, and colleagues have modified the charge coil to automatically adjust the frequency of the magnetic field to the distance of the receiver coil. A voltage amplifier and a resistor coupled to it ensure effective transfer.

The researchers demonstrated that their system works with a prototype: They transferred power wirelessly to an LED, which was slowly moved past the charge coil. Normally, the brightness of the LED is dependent on the distance to the coil. In the experiment, the brightness always stays the same.

So far, the researchers have transferred only one milliwatt with their wireless charge system and also only to a moving object in a one meter radius. But they are confident that this can be significantly increased. They consider charging of electric cars with this technique quite feasible. Mobile devices such as smartphones could also benefit from their technology.

Article Views: 92

Source: Electric Cars Charged While Driving

Wireless, on-the-go charging for electric cars a step closer

The researchers demonstrate their wireless charging model. The bright LED light shows that current is flowing.

Stanford University

Two commercially available components could be the key to one day rolling out electric cars that can be continuously recharged just by driving along the road.

A study published in Nature reveals a modest proof-of-concept experiment that shows how electricity can be transmitted wirelessly. Deployed on a much larger scale, the research opens the door to having transmitter coils embedded into roads, which would then charge up cars as they drove over them.

The study also goes on to show how incorporating a voltage amplifier and feedback resistor into electric car design might overcome the main hurdle any such scheme would face – the need to continually retune the car's magnetic resonance frequency as it moves over the coils.

The study was led by Shanhui Fan of Stanford University in the US. He and colleagues began their work by building on 2007 Massachusetts Institute of Technology research that demonstrated the wireless transmission of electricity over a short distance.

Fan and his colleagues refined that work and succeeded in transmitting power to a moving LED lightbulb. It was a mere one-milliwatt trickle, and electric cars will require a flow many orders of magnitude higher, but until now the base concept had not been demonstrated.

Interestingly, though, the distance over which the power was transmitted – less than a metre – might already be enough.

"We still need to significantly increase the amount of electricity being transferred to charge electric cars, but we may not need to push the distance too much more," says Fan.

Fan's concept relies on a technique called magnetic resonance coupling. In essence, coils of wire held between magnets would be embedded into roads – and also on the undercarriage of cars.

Electricity passing through the wires of the road-based coils creates an oscillating magnetic field. This, in turn, stimulates the electrons in any nearby coil – such as the ones in the cars – to also start to oscillate, thus transferring energy.

This transference, however, only works at optimum levels if the two magnetic fields are oscillating at the same frequency, which only happens if the angle between them doesn't change. In other words, both coils have to be stationary.

For the process to work with a moving vehicle, its onboard transmission coil would have to be constantly recalibrated to take account of the rapidly changing angle between it and the coil in the road – a complex and power-hungry process.

However, Fan and his team worked out that if the car was equipped with a voltage amplifier and feedback resistor – both standard items of electrical engineering kit – the problem can be easily resolved.

"Adding the amplifier allows power to be very efficiently transferred across most of the [one-metre] range and despite the changing orientation of the receiving coil," says team member Sid Assawaworrarit.

"This eliminates the need for automatic and continuous tuning of any aspect of the circuits."

Assawaworrarit tested the set-up using the LED lightbulb model. Without the extra components the LED's intensity rose and fell as it approached, travelled over and went past the power source. With them, the light remained constant.

For Fan, the implications of the wireless charging model are huge.

"We can rethink how to deliver electricity not only to our cars, but to smaller devices on or in our bodies," he says.

"For anything that could benefit from dynamic, wireless charging, this is potentially very important."

In an opinion piece in the same issue of Nature, Geoffroy Lerosey of the Langevin Institute in Paris, France, calls the work of Fan's team a "beautiful concept" that "can have real-life applications" and "builds an inspiring bridge between the worlds of quantum physics and engineering".

Source: Wireless, on-the-go charging for electric cars a step closer

Wireless charging of moving electric vehicles overcomes major hurdle in new Stanford research

June 14, 2017

Stanford scientists have developed a way to wirelessly deliver electricity to moving objects, technology that could one day charge electric vehicles and personal devices like medical implants and cell phones. See video here.

By Mark Golden and Mark Shwartz

If electric cars could recharge while driving down a highway, it would virtually eliminate concerns about their range and lower their cost, perhaps making electricity the standard fuel for vehicles.

Now Stanford University scientists have overcome a major hurdle to such a future by wirelessly transmitting electricity to a nearby moving object. Their results are published in the June 15 edition of Nature.

"In addition to advancing the wireless charging of vehicles and personal devices like cellphones, our new technology may untether robotics in manufacturing, which also are on the move," said Shanhui Fan, a professor of electrical engineering and senior author of the study. "We still need to significantly increase the amount of electricity being transferred to charge electric cars, but we may not need to push the distance too much more."

The group built on existing technology developed in 2007 at MIT for transmitting electricity wirelessly over a distance of a few feet to a stationary object. In the new work, the team transmitted electricity wirelessly to a moving LED lightbulb. That demonstration only involved a 1-milliwatt charge, whereas electric cars often require tens of kilowatts to operate. The team is now working on greatly increasing the amount of electricity that can be transferred, and tweaking the system to extend the transfer distance and improve efficiency.

Driving range

Wireless charging would address a major drawback of plug-in electric cars – their limited driving range. Tesla Motors expects its upcoming Model 3 to go more than 200 miles on a single charge and the Chevy Bolt, which is already on the market, has an advertised range of 238 miles. But electric vehicle batteries generally take several hours to fully recharge. A charge-as-you-drive system would overcome these limitations.

"In theory, one could drive for an unlimited amount of time without having to stop to recharge," Fan explained. "The hope is that you'll be able to charge your electric car while you're driving down the highway. A coil in the bottom of the vehicle could receive electricity from a series of coils connected to an electric current embedded in the road."

Some transportation experts envision an automated highway system where driverless electric vehicles are wirelessly charged by solar power or other renewable energy sources. The goal would be to reduce accidents and dramatically improve the flow of traffic while lowering greenhouse gas emissions.

Wireless technology could also assist GPS navigation of driverless cars. GPS is accurate up to about 35 feet. For safety, autonomous cars need to be in the center of the lane where the transmitter coils would be embedded, providing very precise positioning for GPS satellites.

Magnetic resonance

Mid-range wireless power transfer, as developed at Stanford and other research universities, is based on magnetic resonance coupling. Just as major power plants generate alternating currents by rotating coils of wire between magnets, electricity moving through wires creates an oscillating magnetic field. This field also causes electrons in a nearby coil of wires to oscillate, thereby transferring power wirelessly. The transfer efficiency is further enhanced if both coils are tuned to the same magnetic resonance frequency and are positioned at the correct angle.

Professor Shanhui Fan (left) and graduate student Sid Assawaworrarit have developed a device that can wirelessly charge a moving object at close range. The technology could be used to charge electric cars on the highway, or medical implants and cellphones as you walk nearby. (Image credit: Mark Shwartz/Stanford University)

However, the continuous flow of electricity can only be maintained if some aspects of the circuits, such as the frequency, are manually tuned as the object moves. So, either the energy transmitting coil and receiver coil must remain nearly stationary, or the device must be tuned automatically and continuously – a significantly complex process.

To address the challenge, the Stanford team eliminated the radio-frequency source in the transmitter and replaced it with a commercially available voltage amplifier and feedback resistor. This system automatically figures out the right frequency for different distances without the need for human interference.

"Adding the amplifier allows power to be very efficiently transferred across most of the three-foot range and despite the changing orientation of the receiving coil," said graduate student Sid Assawaworrarit, the study's lead author. "This eliminates the need for automatic and continuous tuning of any aspect of the circuits."

Assawaworrarit tested the approach by placing an LED bulb on the receiving coil. In a conventional setup without active tuning, LED brightness would diminish with distance. In the new setup, the brightness remained constant as the receiver moved away from the source by a distance of about three feet. Fan's team recently filed a patent application for the latest advance.

The group used an off-the-shelf, general-purpose amplifier with a relatively low efficiency of about 10 percent. They say custom-made amplifiers can improve that efficiency to more than 90 percent.

"We can rethink how to deliver electricity not only to our cars, but to smaller devices on or in our bodies," Fan said. "For anything that could benefit from dynamic, wireless charging, this is potentially very important."

Part of the work was supported by the TomKat Center for Sustainable Energy at Stanford.

-30-

Source: Wireless charging of moving electric vehicles overcomes major hurdle in new Stanford research

Nissan Exec Expects Next-Gen EVs Will Boast 310-Mile Electric Range

Nissan LEAFs and e-NV200 at V2G station in the UK

According to Nissan, based on information from the company's commercial vehicle division, the next-generation of EVs will surpass a 310-mile range for cars.

Nissan's e-NV200 light-commercial panel van was released in 2013. It has garnered a decent amount of success for the company, with its hauling capacity of 1,697 pounds and 106-mile range.

Ponz Pandikuthira, vice president for product planning for Nissan Europe, and one of the motivators for moving electrification to Nissan's LCV division, sees positive demands for the improved technology. He recently spoke to the U.K.'s Society of Motor Manufacturers and Traders. He shared:

Nissan e-NV200

"We have more experience with EVs than any other manufacturer, and we've seen a huge uptake in the sales of the e-NV200, especially with delivery companies."

"The threshold for the next generation of EVs is going to be significantly larger than those on the market right now. We're expecting the step-up in range to take us to 250, 350 and 500 kilometers (300 miles) in range for cars."

"Thankfully it's very easy to pass that on to vans, because you can fit the powertrain and batteries to the platform because you have the space. The timing (for launching in the U.K. market) is still to be confirmed, but in the future an electric vehicle will be able to reach 500 kilometers in real-world conditions. Not just during the laboratory-testing process."

"Electrifying commercial vehicles for short haul has its obvious benefits."Something like the NT400 (flatbed truck), for example, is perfect and there are already companies retrofitting electric powertrains to garbage-collection vehicles."

"For the long haul, it's just a case of getting the battery costs down and also working out how to generate the charge."

At the moment, Pandikuthira admits that many consumers still have range anxiety, and tend to prefer hybrids over fully-electric vehicles. He says that this is just a "stepping stone" as EV technology continues to develop and improve. He also believes that plug-in hybrids can be a bridge to all-electric vehicles, but it's only a short-term solution, due to the configuration's excessive weight.

"When we see hybrids, we see a pathway to full electrification. Nissan is obviously working towards zero-emission future, but there are several ways to get there. We're already quite advanced in terms of mild- and microhybrid technology."

"For example, the Note (mini-MPV) with E-Power is the best-selling vehicle in Japan. It works with a range extender, which uses a small combustion engine to charge the battery. This is something that could work with a compact commercial vehicle."

"Then there is plug-in hybrid technology. At the moment, this gives a driver 100 miles (161 km) of electric range and lower emissions for urban driving. Obviously, there are challenges with this technology, because when you add a plug-in system you add a huge amount of mass to the vehicle, sometimes up to 400 kg (881 lbs). That's why we see it as a short-term solution. Plug-in hybrids are a bridge to full-term electrification."

For these reasons, Pandikuthira asserts that the time has come to build vehicles as all-electric models from the beginning. This is more cost-effective than dealing with hybrids and plug-in hybrids, and then working on a transition at a later date. While this may not be entirely possible quite yet, it's the company's target.

"Going forward, we'd like to define vehicles as EVs from the start. That makes it more cost-efficient from a development point of view, but over the next five years we don't think that will be the case for all vehicles. That's why we design them with a sense of interchangeability."

Source: WardsAuto

Source: Nissan Exec Expects Next-Gen EVs Will Boast 310-Mile Electric Range

New law promotes electric car infrastructure in Nevada

Nevada Gov. Brian Sandoval recently signed into law Senate Bill 145 during the 2017 legislative session. The act created the Electric Vehicle Infrastructure Demonstration Program with objectives to enable policies that expand the use of electric vehicles and support the growth of EV infrastructure throughout the state.

During the Great Recession, a worldwide financial crash devastated the U.S. automotive industry and forced the federal government to intervene to save American jobs. U.S. taxpayers temporarily acquired General Motors during bankruptcy restructuring, guaranteed private-sector loans to Ford Motor Co. and backed the acquisition of Chrysler by Fiat, after Chrysler had split from a merger agreement with Daimler.

The Obama administration also negotiated Corporate Average Fuel Economy standards that were accepted by the automotive industry. The CAFE program set target thresholds for fuel efficiency over the following decade and drove the development of innovative automotive technologies.

In response, automotive manufacturers delivered more fuel-efficient power train technologies that included two categories of plug-in electric cars.

Plug-in hybrid electric vehicles like the Chevrolet Volt, Ford Fusion Energi and Prius Prime can be driven by an electric motor but also employ a gasoline engine for extended range.

Battery-powered electric cars, such as the Nissan Leaf, Ford Focus EV, BMW i3, Tesla Model S and Tesla Model X rely solely on the availability of electricity for fuel and an onboard storage battery to determine traveling distance for its electric motor.

During February 2011, an Electric Vehicle Infrastructure Readiness Task Force was first formed in Nevada as a partnership of the NV Energy electric utility, the Nevada Department of Transportation, the Nevada State Office of Energy and REA250.org, a nonprofit organization that was tasked with administering the task force goals.

Participants were recruited from state, county and municipal governments, as well as from the business community, academic institutions and nonprofit organizations, to focus on four objectives that would prepare the state for electric car technologies: educational outreach, infrastructure development, legal code standardization and fleet development.

During 2012, the task force was renamed the Nevada Electric Vehicle Accelerator program, and an informational website was developed at nevadaeva.org.

While gasoline and diesel fuel have been imported into Nevada from other states, electricity has the potential to be generated locally to provide storable power for electric cars. Photovoltaic solar panels, solar thermal generators, geothermal turbines, wind power turbines, hydroelectric dams and other sustainable electric power resources can be harnessed throughout the state.

Electric cars are normally refueled by plugging a charging cable into any electric outlet overnight in order to draw electrons from the utility grid. However, when traveling away from a home base during the day, "range anxiety" was perceived as a deterrent for potential electric car buyers.

Most early battery-powered electric car models, introduced just five years ago, only had a range of 60 to 100 miles initially. Tesla Motors vehicles were an exception, with battery pack ranges exceeding 200 miles of travel, but Tesla electric cars, such as the Model S and Model X, also cost at least twice as much for potential buyers.

During 2012 and 2013, NV Energy formed partnerships with strategic host sites to place public recharging stations for electric cars in strategic areas around urban metropolitan areas in the state, especially the Las Vegas valley in the south and the Reno-Sparks-Carson City region in the north.

Each of the stations in the network employed a standard universal plug connector adopted by the worldwide automotive industry and SAE International, known as SAE J1772. The mating plug and socket connectors had five pins arranged in a star configuration, including three big pins for transferring electric power and two small pins for transferring data signals between the recharging station and the electric car's onboard battery management system.

Each ChargePoint station included a wireless modem that could communicate its operating status to an internet network that was constantly monitored by ChargePoint service technicians, as well as a supervising manager at NV Energy. The NV Energy manager could then contact local host sites to perform maintenance and repairs, if needed.

A foundational network of electric vehicle supply equipment was established throughout the state by NV Energy and its partners, while other supporting organizations also installed EVSE charging stations independently.

"Through our shared investment program, we've partnered with more than 50 companies in Reno and Las Vegas to install EV charging stations at airports, casinos, shopping centers, universities and more. Since 2013, these systems have recorded nearly 106,000 charging sessions, saved over 98,000 gallons of gas and reduced greenhouse gas emissions in Nevada by 364 tons," said Pat Egan, senior vice president of renewable energy and smart infrastructure for NV Energy.

There are now more than 200 public charging station sites throughout Nevada, and the infrastructure continues to grow. To find the location of a local electric car recharging site, visit PlugShare.com.

Tesla has also maintained its own proprietary network of Supercharger stations throughout the country to enable long-distance travel for its electric car models at intervals of 200 miles. The Supercharger systems provide high-voltage DC power that can recharge the larger Tesla model electric car battery packs within about one hour at each stop.

A Supercharger site on Bridger Street in downtown Las Vegas became the first installation outside of California and drew electric car drivers from Los Angeles to the Las Vegas Strip. There are now 11 Tesla Supercharger sites in Nevada at Primm, Las Vegas, Beatty, Tonopah, Hawthorne, Gardnerville, Reno, Winnemucca, Elko, Lovelock and West Wendover.

However, the plug connectors and electronic circuitry inside Tesla Superchargers can only recharge Tesla model vehicles at this fast rate of speed, because of the company's proprietary battery technology and electronic management system.

Other worldwide automotive manufacturers have not adopted the Tesla standard for DC fast charging systems, but have split into two competing standards camps.

Tokyo Power Co. developed the early CHAdeMO connector standard accepted by automotive manufacturers in Japan and South Korea for DC fast charge systems. CHAdeMO-equipped connectors were upgrade options for production models of the Nissan Leaf, Mitsubishi i-MiEV and Kia Soul EV. However, the option required two charging ports and separate circuitry for each car, one for the universal SAE J1772 standard and a second for the CHAdeMO connector standard.

SAE International developed a follow-up standard that combined three different levels of AC and DC charging protocols into one connector standard known as the SAE Combo.

European and US automotive manufacturers have begun employing the SAE Combo standard for the BMW i3 and Chevrolet Bolt EV.

During 2015, NRG EVgo partnered with Terrible Herbst Oil Co. in Las Vegas to provide a dozen DC fast charge stations that utilized both CHAdeMO and SAE Combo plugs. The companies installed them at strategic host sites within Terrible Herbst gasoline service stations around the Las Vegas Valley.

Although there is a connection fee and consumption fee that totals about $10 for each charging session for a range of 100 miles, each DC fast charge station can recharge a Nissan Leaf or BMW i3 battery pack in less than 30 minutes. Nissan also offers a "No Charge to Charge" program that provides free access to the NRG EVgo charging stations along US highways for two years when purchasing a new Nissan Leaf.

Most 2017 and 2018 models of battery-powered electric cars have a range of at least 120 miles. Many automotive manufacturers are planning to upgrade existing models to at least a 200-mile range within the next three years as lithium-ion battery costs decline.

The Chevrolet Bolt EV has a battery pack range of 238 miles and should be available in local Nevada dealerships by the fourth quarter of this year.

Tesla will also begin manufacturing its lower-cost Model 3 electric car this year with an estimated range of at least 215 miles but with optional battery pack upgrades to 259, 294 and 315 miles, accompanied by incremental price increases.

Battery pack modules and power train components for the Model 3 will be manufactured at the Tesla Gigafactory, located east of Reno in Storey County.

Stan Hanel is an outreach coordinator for the Nevada Electric Vehicle Accelerator program administered by REA250.org, a nonprofit organization, and serves on the board of directors for the Las Vegas Electric Vehicle Association.

Source: New law promotes electric car infrastructure in Nevada

Electric Car Owners in Minnesota to Face $75 Annual Fee

The fee is expected to generate about $40,000 the first two years, but revenue estimates more than double in the two years after that.

The surcharge applies to what are called "all-electric vehicles," which are able to draw power solely from rechargeable batteries, fuel cells or other electrical currents. Plug-in hybrids that require some gasoline to run wouldn't be subject to the fee.

(Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)

Source: Electric Car Owners in Minnesota to Face $75 Annual Fee

Electric car subsidies may do more harm than good

Globally, from China and Germany to the United States, electric vehicle (EV) subsidies have been championed as an effective strategy to boost production of renewable technology and reduce greenhouse gas emissions (GHG).

But a new study by Concordia economics professor Ian Irvine shows that subsidizing EVs in the North American context will not reduce GHG emissions in the short-term, and may even increase them -- at a cost to taxpayers.

Recently published in Canadian Public Policy, Irvine's study compared the incentives for producing EVs that are found in the Corporate Average Fuel Economy (CAFE) standards, North America's fuel-efficiency regulations, with new EV subsidy policies in Ontario, Quebec and British Columbia.

He found that, while the subsidies encourage the production of more EVs, they undermine the efficiency requirements of existing incentives for conventional vehicles. This results in a zero or negative near-term GHG benefit.

"Sometimes you have more than one policy aimed at a particular goal, and usually those policies are complementary," Irvine notes. "But in this case, they work at cross purposes."

In 2012, CAFE was amended to require manufacturers to continuously reduce the average carbon dioxide (CO2) emissions of their fleets by five per cent a year between 2017 and 2025.

Typically, the amount of CO2 each vehicle is allowed to emit is related to its footprint, defined as the area between its wheels. However, Irvine says, because the annual GHG reduction targets are organized on an average fleet-wide basis, manufacturers are allowed some flexibility in how they distribute the annual efficiency improvements within and across different vehicle categories.

'This is what we call a regressive policy'

Under CAFE's rules, an electric car is considered to have a zero emissions footprint. As an incentive designed to stimulate investment in EVs, a manufacturer that produces an EV is given a carbon credit that can be sold to another manufacturer, applied to a future year or applied to other vehicles in the manufacturer's fleet.

As a further incentive, the manufacturer is granted a bonus carbon credit over and above the equivalent of CO2 that the sale of the EV removes from the atmosphere. For EVs, this bonus credit, or multiplier, started at 2.5 in 2016 and declines to 1.5 in 2025.

As Irvine illustrates, if a vehicle with a footprint of 50 square feet is allowed to emit 150 grams of CO2/kilometre, then a manufacturer who sold an EV with the same footprint in 2016 is given an emission credit of 375 grams of CO2/kilometre.

"These carbon credit offsets can be used by a manufacturer to moderate the GHG-related efficiency improvements in the more conventional vehicles that they sell," Irvine says. "So, putting more EVs on the road with subsidies does not translate into fewer GHG emissions."

What's more, the subsidy policies apply to all potential buyers, not just those who wouldn't otherwise have the means to purchase EVs. According to Irvine, this is an inefficient and wasteful use of taxpayer money.

"Research shows that subsidies for vehicle purchases typically benefit the top ten percentile of income distribution," says Irvine. "This is what we call a regressive policy."

All told, Irvine sees the prime lesson of his study to be caution.

"In developing these types of policies, we need to look before we leap," he says. "In Ontario, we're giving grants of up to $14,000 to EV purchases. That's a lot of taxpayer money. And if people think it's going toward reducing GHG emissions, we should confront that misunderstanding."

Source: Electric car subsidies may do more harm than good