A 17-year-old engineer's magnet-free motor prototype could make electric vehicles more sustainable

 

A young engineer called Robert Sansone won the first prize, and winnings of $75,000, at this year's Regeneron International Science and Engineering Fair (ISEF), the world's largest international high school STEM competition.

As per Smithsonian Magazine, his new invention could one day transform the electric vehicle (EV) industry. It is a synchronous reluctance motor with improved performance over previous models.

Typically these types of motors are used for pumps and fans, but they aren't powerful enough for EVs. Sansone's new model improves the torque of these motors, which don't require costly and often unethically sourced rare-earth metals.

A promising young engineer

Sansone, who is only 17 years old, estimates he has completed approximately 60 engineering projects in his spare time. The Florida-based inventor has built animatronic hands, a 70-mph go-kart, and high-speed running boots, among several other innovations.

Roughly two years ago, Sansone came across a video explaining the advantages and disadvantages of electric cars. The video described how EV motors typically use rare-earth metals, which are expensive and often sourced in a way that is bad for the environment.

The high-schooler set out to improve on existing models of the synchronous reluctance motor, as it doesn't require rare-earth metals. Over the course of a year, he created a prototype for a new type of synchronous reluctance motor that has greater torque and efficiency than existing models. The prototype was made of 3D-printed plastic, copper wires, and a steel rotor. The work on this prototype, which was tested using a laser tachometer to determine torque, bagged Sansone the top prize at ISEF, the George D. Yancopoulos Innovator Award.

Rethinking the synchronous reluctance motor

Large firms, including BMW and MAHLE, are developing magnet-free motors for the same reasons as Sansone. Namely, the production of regular magnet motors is a stain on the EV industry, which is otherwise geared towards sustainability. The vast majority of the rare-earth metals required are mined in China, meaning the western EV industry is currently highly reliant on their imports.

BMW's fifth-generation electric motor, which will power its new BMW iX M60, is magnet-free and doesn't use rare-earth metals. BMW announced that the standard combined output of the front and rear motor of its new iX M60 will be 532 hp and 749 lb-ft of torque. Auto parts manufacturer MAHLE, meanwhile, also released its own magnet-free electric motor that does not require rare earth elements. That motor uses a special design to generate torque via contactless power transmission, which makes it wear-free and also highly efficient at high speeds.

Sansone's motor uses a different type of design. Synchronous reluctance motors use a steel rotor, with air gaps cut into it, aligned with a rotating magnetic field. The motor generates a magnetic field using magnetic reluctance. Sansone tweaked the typical synchronous reluctance motor design by removing the air gaps to incorporate another magnetic field by adding more materials. Unfortunately, he hasn't yet disclosed any more information as he is hoping to patent his design.

Sansone says it took him 15 attempts to make a prototype that worked. After running some tests, he found that the novel design exhibited 39 percent greater torque and 31 percent greater efficiency at 300 revolutions per minute (RPM) than a traditional synchronous reluctance motor he used for comparison. At 750 RPM, it showed 37 percent greater efficiency. Sansone couldn't test his motor at a higher RPM due to the fact that the plastic prototype would melt. Now that he's gained acclaim and attention for his design, he will hopefully be able to run tests on a fully functional motor prototype using more sturdy materials. We'll be sure to bring you updates if and when he does.