One of the biggest challenges to the widespread adoption of electric cars is charging them. Many potential electric car drivers have concerns about range or don’t want to spend a lot of time charging the electric car’s battery on long journeys. Wireless charging of electric cars may seem like something out of a science fiction movie, but it could be a viable way to solve the problems of charging electric cars. These wireless energy transfer systems work while the vehicle is in motion and offer numerous advantages.
As electric cars become more popular and are used in a variety of applications, such as delivery vehicles, company fleets and for personal trips, it will be crucial to charge electric car batteries without compromising the range of the vehicle. While the battery capacity and range of EVs have increased significantly in recent years, charging solutions can also make the use of EVs more viable across the board. It is therefore worthwhile for EV experts to understand the developments in the industry in order to implement innovative approaches for a carbon-neutral world.
What is wireless charging for electric vehicles?
Unlike static charging, dynamic wireless charging for electric vehicles, or charging while driving, allows electric cars and trucks to charge continuously as they drive, so they don’t have to stop to refuel or recharge. Instead, they receive a constant stream of energy through an air gap while the vehicle is in motion. In these systems, a high-frequency inverter is used to generate the alternating magnetic field required to wirelessly transmit power to the vehicle through electromagnetic induction. In other words, the public infrastructure is used for advanced charging of electric vehicle batteries.
However, inductive charging or inductive energy transfer is not a new phenomenon. You may already be using this technology at home with an electric toothbrush or a wireless cell phone charger. Wireless power transfer via magnetic resonance (WPT) uses inductive charging via a pad on the ground and a receiver in the vehicle that is tuned to the same frequency. The advantage is that the modules do not need to be perfectly aligned to transmit energy if they operate on the same operating frequency.
“A key benefit of this technology is that it opens up new areas of the transportation sector for electrification,” – said Burak Ozpineci, head of the Vehicle and Mobility Systems Research Division at the U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL). “It’s not just about fast charging of vehicles. It’s also about the ability to convert long-haul trucks, which consume a significant portion of the fuel used in this country, to electricity.”
Despite the challenges, momentum is growing as companies coalesce around a standardized technology and automakers and municipalities explore use cases. Even Tesla has shown interest in wireless charging technology. Pilot projects are currently underway, with trials focusing on both passenger and commercial vehicles. SAE International is also working on standardization, which could further accelerate the adoption of dynamic wireless charging.
What research has been done in the area of dynamic wireless charging for electric vehicles?
The DOE and ORNL are working to develop dynamic wireless charging for electric vehicles to make electric vehicle use more convenient and cost-effective for consumers and to facilitate use at highway speeds. The goal is to integrate highly efficient wireless charging technology into the national grid and maintain charging performance for high-speed applications.
Partners include Idaho National Laboratory, the National Renewable Energy Laboratory, Hyundai Motor Group, the American Center for Mobility and the Virginia Tech Transportation Institute. The work is also supported by the DOE Office of Energy Efficiency and Renewable Energy’s Vehicle Technologies Office.
The researchers have already achieved a number of technical accomplishments, including high-level cost and feasibility studies, identifying a suitable architecture for 200 kW dynamic wireless power transfer (DWPT) couplers, and analyzing the feasibility of large-scale deployment on Atlanta’s major roadways. Some researchers are looking at vehicle misalignment, safety in electromagnetic fields, and power density and efficiency challenges due to high current (~750 A), high voltage (~4 kV), and high frequency (~85 kHz).
ORNL has developed a dynamic wireless charging technology for electric vehicles and licensed it to Brooklyn-based HEVO. The license includes ORNL’s unique multiphase electromagnetic coil and Oak Ridge converter. Under the terms of the agreement, ORNL and HEVO will work together to prepare the technology for commercial production.
“We are excited to see another one of our technologies reach the private sector, where it can create new green jobs and support national clean energy goals,” said Xin Sun, deputy director of ORNL
– xin Sun, deputy director of the Energy Science and Technology Laboratory at ORNL, said.
“Electric vehicle charging must be simple, seamless and safe to accelerate mass adoption and prepare for an autonomous future,” said Jeremy McCool, head of ORNL
– said Jeremy McCool,
founder and CEO of HEVO. “Our partnership with ORNL leverages HEVO’s strength in designing, developing and commercializing wireless charging technology and software as the first and only company in the world to meet both SAE and UL-compliant safety and performance requirements
Detroit has made the first foray into wireless charging for electric vehicles.
The Motor City has the first public wireless charging lane for electric vehicles in the U.S. on a quarter-mile stretch of Corktown. In November 2023. the Michigan Department of Transportation (MDOT) and the City of Detroit unveiled the new lane on 14th Street between Marantette and Dalzelle streets near Michigan Central Station.
“The development of electrified roadways can be a catalyst to accelerate interest and adoption of electric vehicles by all consumers,” said MDOT Director Bradley C. Wieferich. “Making it easier for electric vehicle users to find a reliable charging station without interrupting their commute supports both fleet operations and personal transportation. We are proud to work with private sector partners and the City of Detroit to support these important initiatives that will lead us to a more sustainable future with fewer emissions.”
This proving ground is significant because Ford Motor Co. is actively building a campus for electric and autonomous vehicles. The road was equipped with inductive charging coils supplied by Electreon Wireless Ltd, an Israeli company. This installation for wireless charging of electric vehicles is intended to evaluate the effectiveness of the technology and explore its potential applications in public transportation. However, only electric vehicles equipped with a special wireless charging receiver can use this charging infrastructure.
“We are pleased to be leading the development and implementation of America’s first wireless charging street,” said Dr. Stefan Tongur, Electronica – said Dr. Stefan Tongur, Vice President of Business Development at Electreon. “This milestone is a testament to our collaboration with the State of Michigan and MDOT, the City of Detroit, Michigan Central, Ford, Jacobs, Next Energy, DTE and others. Together with Michigan’s expertise in the automotive industry, we will demonstrate how wireless charging enables the widespread adoption of electric vehicles by overcoming limited range, grid constraints, and battery size and cost. This project paves the way for a zero-emission mobility future where electric vehicles are the norm, not the exception.”
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Advantages and disadvantages of wireless charging for electric vehicles.
While wireless charging technology for electric vehicles has many advantages, its commercial viability still has some challenges to overcome, and further research and evaluation is needed.
Potential benefits of dynamic charging.
If wireless charging technology for electric vehicles can be refined and implemented into the infrastructure, the widespread use of dynamic inductive power transfer has many potential benefits.
- Continuous charging of electric vehicle batteries can reduce range issues as vehicles can be charged while driving, which could increase their market share.
- Effective dynamic charging solutions reduce the need for charging stations and thus save space.
- Continuous charging reduces the size of an electric vehicle’s battery while reducing its weight, helping to lower the cost of electric vehicles and save on materials.
- Dynamic charging is more convenient than using gas stations or stationary charging stations for electric vehicles, as it saves time and helps to increase the popularity and appeal of electric vehicles.
- If wireless charging technology for electric vehicles catches on, it could accelerate the transition to cleaner energy sources and help mitigate climate change.
- The range of applications for electric vehicles, including long-haul trucks, will be expanded.
Disadvantages of wireless charging for electric vehicles.
While dynamic wireless charging is promising, it also presents challenges that require further research and funding.
- Further research is needed to increase the performance and efficiency of existing technology. For example, misalignment or a deviation in the position of the receiving coil from the optimal position above the transmitting coil can affect the performance and reliability of wireless dynamic charging systems.
- Finding space for a wireless charging station and devices on the underside of an existing vehicle can be a challenge.
- Overcome the technological challenges of vehicle body interference with power transmission performance.
- Upgrading the infrastructure and integrating dynamic wireless charging capabilities into the existing design for widespread deployment would be costly.
Which electric vehicles are equipped with a dynamic charging function?
Currently, the only electric vehicle available in the U.S. with integrated wireless charging capability is the BMW 530e hybrid sedan. WiTricity, a wireless charging provider that secured a $25 million investment from Siemens in 2022, is actively working on licensing agreements. These agreements, which have attracted the attention of General Motors, are part of WiTricity’s ongoing efforts to develop wireless charging technology.
Is there a lot of interest in wireless charging for electric vehicles?
According to WiTricity, there is strong consumer demand for dynamic wireless charging. WiTricity surveyed 1,000 people in the U.S. who own or are considering buying an electric vehicle and found that 81% are very interested in electric vehicles with wireless charging.
Legislation to support dynamic charging for electric cars.
Representative Haley Stevens of Michigan has introduced the Electric Vehicle Wireless Charging Grant Program Act of 2023. The bill aims to establish a grant initiative within the U.S. Department of Transportation (DOT) to support dynamic wireless charging of electric vehicles. Inspired by a pilot program in Michigan, the Dynamic Wireless Charging Act aims to put the U.S. at the forefront of this technology.
“Dynamic wireless charging has the tremendous potential to revolutionize the way electric vehicles are charged and could enable widespread adoption of electric vehicles by addressing some of the biggest challenges of electrification,” Rep. Stevens
– congresswoman Stevens said.
“Michigan is an innovative state that is driving the future of electric vehicles, and making charging easier for consumers is the next step. Investing in new electric vehicle technologies is critical to increasing America’s global competitiveness. Wireless charging can reduce the size and cost of batteries, increase range, reduce pressure on the grid and enable the electrification of autonomous vehicles.”
Dynamic charging of electric vehicles can help increase their popularity.
As electric vehicles gain traction in the automotive market and help reduce emissions, fossil fuel consumption and pollution, convenient charging solutions will become increasingly important. Wireless charging of electric cars has the potential to accelerate the electrification of vehicles and their uptake. Due to its incredible potential, intensive research is being conducted into high-performance wireless charging systems.