Electric Vehicle Technology
December 21, 2023

Charging Ahead for Safer Wireless Power Transfers

Wireless Power Transfer

Our Long History in EV Safety 

ULSE has been at the forefront of setting requirements for EVs, publishing our first set of requirements in 1996. By 2002, when the first EVs began to roll off production lines, auto makers already adopted ULSE standards to help prevent electrical shock hazards for EV users. Since then, the market for EVs has seen steady year-over-year growth and innovation, meaning ULSE and technical committee members continually review and update existing standards while publishing new ones. 

The Potential of WPT 

The newest EV innovation, which has been long anticipated, is WPT. Removing the thick charging cables needed for standard EV charging has been the top demand of countless homeowners who do not have space to accommodate them in their garage.  

Modern WPT needs two primary pieces of equipment to efficiently transfer power between the charging station and the vehicle. Since these two pieces, called the power source and ground assembly, have the highest potential for failure or injury, ULSE quickly convened a team of experts to create UL 2750 Wireless Power Transfer Equipment for Electric Vehicles which was published in November, 2023. This standard covers both indoor and outdoor use assemblies, whether cord and plug connected or permanent. 

How UL 2750 Mitigates Risk 

Perhaps the most concerning situation with EV charging, especially via WPT, is the potential for a pet or child to be caught between the vehicle and ground assembly. This is dangerous for many obvious reasons and many manufacturers have incorporated living object detection (LOD) systems to recognize when organic creatures enter the charging space. These LOD systems shut off power transfer until the situation is safely resolved to prevent injury or worse. Our standard helps ensure that the software and components used in WPT LOD systems are thoroughly evaluated to the point of misuse. In turn, this ensures that these components can withstand a variety of conditions in the typical operating environment. 

Another concern for homeowners and business owners is the large metallic frame that supports the WPT station. Metal can carry electrical current, and with the substantial amounts of power necessary to charge an entire vehicle, there is a valid concern that the frame could become a giant conductor which may be grabbed or leaned on during normal use. ULSE has accounted for this issue and UL 2750 requires grounding and bonding of these metal parts to mitigate the risk of electric shock. In addition to those requirements, to conform with UL 2750, the enclosure must also be constructed robustly enough to contain items, such as molten metal or any flaming particles from leaving the enclosure, mitigating the risk of fire. 

Construction requirements in the standard dictate the thickness of enclosure materials and the location and size of vents to ensure that objects and tiny fingers can’t work their way into the electrical components preventing the risk of electric shock.  

Join Us in Making the World a Safer Place 

As the world of EVs continues to evolve, ULSE remains committed to revising existing standards or publishing new ones to stay ahead of potential risks as new research or technology is developed.  Standards have the unique ability to mitigate risks such as injury, death or property loss without inhibiting innovation. With EV fires on the rise, standards are a means of providing impactful, sustainable solutions. 

Our standards are developed through a consensus-based process, which integrates scientific and testing expertise with input from our technical committee members and stakeholders. TC members represent a variety of interests, including industry, academia, government, retail, and manufacturing. If you are involved in EV innovation and would like to help improve safety in your industry, learn more about how to get involved