Dynamic Wireless Charging For Electric Vehicles (EVs)
One of the significant challenges with widespread electric vehicle adoption is related to vehicle charging. Many potential EV drivers have range anxiety or don’t want to spend much time charging an EV battery on long trips. Although dynamic wireless charging may seem like something out of a science fiction movie, it could be a viable way to overcome vehicle charging issues. These wireless power transfer systems work while the vehicle is in motion, providing numerous benefits.
As EVs grow in popularity and are used in a variety of applications, such as delivery vehicles, corporate fleets, and personal trips, it will be critical to keep EV batteries charged without hindering vehicle range. Although the capacity and driving range of EV batteries has expanded significantly in recent years, charging solutions can also make EVs more viable for widespread use. Therefore, it is helpful for EV professionals to understand industry developments to help implement innovative approaches in creating a carbon-neutral world.
What Is Dynamic Wireless Charging?
Unlike static charging, dynamic wireless charging allows EVs to charge on the go, so vehicles do not need to stop to refuel or recharge. Instead, they receive a constant stream of energy across an air gap while the vehicle is in motion. Wires under the road transmit electricity to EVs, using the principle of magnetic induction. In other words, public infrastructure is used for advanced battery charging.
Inductive charging is not a new phenomenon, and you may already use this technology in your home with an electric toothbrush or wireless cell phone charger. Magnetic resonance wireless power transfer (WPT) uses induction charging with a pad on the ground and a receiver on the vehicle that is tuned to the same frequency. The advantage is the modules don’t need to be perfectly aligned to transfer power if they are on the same operating frequency.
“Opening up new parts of the transportation sector to electrification is a key benefit of this technology,” said Burak Ozpineci, section head for Vehicle and Mobility Systems Research at U.S. Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL). “It’s not just about charging your vehicle really fast. It’s also about being able to convert to electricity long-haul trucks, which burn a significant portion of the vehicle fuel used in this country.”
What Research Has Been Done So Far?
The DOE and ORNL are working to advance dynamic wireless EV charging to make EV use more convenient, cost-effective for consumers, and viable at highway speeds. The goal is to integrate high-efficiency wireless charging technology with the nation’s power grid and maintain charging power for high-speed applications.
Collaborators include Idaho National Laboratory, the National Renewable Energy Laboratory, Hyundai Motor Group, American Center for Mobility, and Virginia Tech Transportation Institute. This work is also supported by the DOE Office of Energy Efficiency and Renewable Energy’s Vehicle Technologies Office.
Researchers have already achieved numerous technical accomplishments, including high-level cost and feasibility studies, identifying a suitable architecture for 200 kW dynamic wireless power transfer (DWPT) couplers, and analyzing large-scale deployment feasibility on Atlanta's primary roadways. Some research explores vehicle misalignment, electromagnetic field safety, and power density and efficiency challenges due to high current (~750A), high voltage (~4kV), and high frequency (~85 kHz) operation.
The ORNL has developed dynamic wireless EV charging technology and has licensed it to Brooklyn-based HEVO. The license includes ORNL’s unique polyphase electromagnetic coil and the Oak Ridge Converter. Under the agreement, ORNL and HEVO will work together to prepare the technology for commercial manufacturing.
“We are excited to see another one of our technologies move into the private sector where it can create new green jobs and support the nation’s clean energy goals,” said Xin Sun, associate laboratory director for energy science and technology at ORNL.
“EV charging must be simple, seamless and safe in order to accelerate mass adoption and prepare for an autonomous future,” said Jeremy McCool, HEVO founder and CEO. “Our collaboration with ORNL utilizes HEVO’s strength in designing, developing and commercializing wireless charging technology and software as the first and only company in the world that is compliant with both SAE and UL safety and performance standards.”
Potential Benefits And Obstacles To Wireless Charging Infrastructure
Although wireless electric vehicle charging technology has many benefits, there are some challenges to overcome in making it commercially viable, and more research and evaluation are needed.
If the technology can be perfected and implemented in infrastructure, there are many potential advantages to the widespread use of dynamic inductive power transfer.
Continuous electric vehicle battery charging can alleviate range anxiety because vehicles can charge as they move, potentially boosting their market share.
Effective DWPT solutions reduce the need for plug-in charging stations, saving space.
Ongoing charging allows for a smaller EV battery size with reduced weight, helping to decrease the cost of EVs and conserving materials.
Dynamic charging is more convenient than using a gas station or stationary EV charging system because they save time, helping to boost the popularity and appeal of EVs.
If the technology becomes widely used, it could accelerate the transition to cleaner energy sources and help mitigate climate change.
Increases the potential uses for electric vehicles, including long-haul trucks.
More research is needed to boost the power levels and efficiency of the existing technology.
Finding the space for the charging pad and equipment on the underside of an existing vehicle can be challenging.
Overcoming technological challenges related to vehicle body interference with power transfer efficiency.
Retrofitting infrastructure with this charging technology for widespread implementation would be costly.
Conclusion: Dynamic Wireless Charging Could Help EV Adoption Rates In The Future
As EVs gain market share in the automotive industry and help reduce vehicle emissions and fossil fuel energy consumption, convenient battery charging solutions are becoming increasingly critical.
Dynamic wireless charging has the potential to advance vehicle electrification and widespread adoption, with significant research going into high-power wireless charging systems due to their amazing potential.
While dynamic wireless charging research is promising, it’s a long way from being implemented at scale. GreenLancer EV's marketplace offers design and engineering for EV charging infrastructure contractors who are looking to scale and install batch projects with simplicity and support.