Blog – Wireless Power
Here are blog posts on wireless power.
CNET reports that Nissan is planning to offer inductive charging for the Nissan Leaf.
Nissan has been experimenting with inductive charging – a way of transferring power without a physical conductor – for a number of years. The earliest versions involved a circular module, nicknamed the ‘charging turtle’ because it looks a little like a turtle shell that is placed on the floor underneath the vehicle, and required the car be positioned directly over the charging turtle to transfer power. Nissan even developed an automatic parking technology to position the car for maximum charging efficiency.
It appears that the technology is improving and may be able to be placed in a bumper for recharging at your favorite restaurant or hotel. Long term, the technology could be implanted in the roadways, allowing vehicles to charge on the move and reducing the size of battery that an EV would require.
What’s changed? Advances made earlier this century in using strongly coupled inductive resonance for power transfer has increased the distance that power can be transferred with high enough efficiencies to make it worthwhile. Inductive resonance is similar to how a tuning fork will sound with the same pitch if the note it is tuned for is played on a nearby instrument. When an AC current is passed through a coil at a certain frequency, a coil, or even a series of coils, tuned to the same frequency that is nearby – as far as several feet – will pick up a current that can be used to power a motor or recharge a battery.
Nissan’s efforts may be another means of eliminating EV range anxiety and bringing about the obsolescence of the gas burning vehicle. That’s good for everyone’s health and to reduce global warming.
New research from North Carolina State University and Carnegie Mellon University shows that wireless power transfer efficiency can be more than doubled using a MRFE – Magnetic Resonance Field Enhancer.
Wireless power transfer has been around for years, but until recently was limited in range to a few inches. Recent advances in magnetic resonance have improved ranges to several feet. Magnetic waves, much like audio waves, resonate at particular frequencies. Tapping a tuning fork set for C flat will cause an nearby tuning fork tuned to C flat to vibrate and issue the same note. When two metal coils are tuned to the same frequency, running AC current at the tuned frequency in the first coil can induce a current in the second coil.
The MRFE is a device that can be as simple as a copper loop that is tuned to the frequency of the power transfer system and, based on the research, improves the efficiency of the whole system. This has potential to make wireless power transfer a practical solution for electric vehicle chargers.
Over the past week, we saw a flurry of marquee developments in the clean energy sector. Among them, Tesla and Panasonic partnering on the $5 billion “Gigafactory,” Bosch and BMW launching a sub $10K EV charger, Stanford researchers scoring a break through in lithium battery capabilities, and Solar Roadways raising more than $2.2 million in its Indiegogo fundraising campaign.
Tesla’s bold plan to build 500,000 EVs per year by 2020 and deliver an EV that competes in the $35K range (Model 3) by 2017, hinges on its ability to dramatically reduce the cost of its batteries. Its solution, the Gigafactory, a planned super warehouse capable of scaling its operations to meet growing demand for EV batteries. Panasonic recently agreed to partner with the Palo Alto-based company and is helping foot the estimated $5 billion price tag. Panasonic insists its investment will be incremental and likely not exceed $1 billion. Even so, this relationship provides Tesla with a sorely needed partner to help shoulder the cost, burden, and risk of such a dramatic and ambitious move. Panasonic’s commitment adds to the $2.3 billion Tesla raised in March. While the factory location has still not been finalized, sites in Nevada, California, and Texas are rumored to be the favorites.
In other news, Bosch will supply and install the BMW i DC Fast Charger for North American BMW i Centers and authorized partners, starting this month. The sub $10k charger is more compact and comes with a friendlier price tag than competing chargers. It can charge a BMW i3 battery to 80 percent in 30 minutes.
Stanford researchers say they have made a major step toward creating a “pure lithium battery.” According to USA Today, a team that includes former Energy secretary Steven Chu, says it’s building a lithium anode battery that might give electric vehicles a 300-mile driving range and triple a cellphone’s juice. The Stanford team is using nanotechnology to help build a battery that has the potential to be a game changer in a variety of industries. Researchers say it will likely take three to five years to bring the product to market.
Solar Roadways, a company that plans to replace concrete and asphalt surfaces with solar panels that can withstand the heaviest of trucks (250,000 pounds), raised more than $2.2 million in its Indiegogo fundraising campaign that ended in June. The Idaho-based company has received two phases of funding from the U.S. Federal Highway Administration for its research and development. Its glass surface has been tested for traction, load testing, and impact resistance. Tests exceeded all requirements.
WiTricity, the wireless charging pioneer, has received $25 million in Series E funding. WiTricity developed much of the current wireless power transfer technology that allows power transfer over longer distances than 20th century technology allowed. This is good news for the wireless power transfer industry and the eventual development of inductive charging roads.
Here’s the link to the Chargedevs.com article:
WiTricity produces a demonstration product on Wireless Power Transfer called Prodigy. This system is a good way to teach about wireless power transfer and learn more about how such a system work.
Here’s a link to the WiTricity Prodigy website :