The use of rare earths in various modern technology has drawn attention over the years. But with the rising demand for electric vehicles , the issue has been brought to the fore.In 2022, 82% of the electric car market was using electric motors based on rare earth permanent magnets. China largely controls the supply of rare earths, and this has led to significant price volatility in previous years, with a large spike in 2011/2012 and a big rise between 2021-2022.
These motors typically present good peak power and torque density over short periods but can prove challenging to thermally manage and typically have lower efficiency than PM options. Despite their simplicity and reliability, SRMs have typically been plagued with poorer power and torque density with other issues, including torque ripple and acoustic noise.
Proterial has developed magnets with magnetic properties that it states “deliver the world’s highest levels among ferrite magnets”. The motor design only requires 20% more magnetic material to keep the motor power density the same. Niron Magnetics are developing iron nitride magnets, and its next-generation versions are planned to compete with neodymium performance.