© fotosonar dreamstime.com Analysis | March 21, 2013
China's stranglehold on Rare-Earth mineral supply
China’s move to corner the market for rare-earth minerals (REMs) has prompted manufacturers of low voltage industrial motors to adopt alternative technologies that reduce or eliminate the use of these materials, spurring new growth in the motors market.
The global market for industrial IE4 Super Premium Efficiency low voltage motors will reach an estimated $418.2 million by the end of 2015, up 153% percent from $165.4 million in 2012, according to IHS IMS Research. Emerging lower-cost alternatives to traditional permanent magnet synchronous motors (PMSMs) that achieve IE4 levels of efficiency have added momentum to this niche market. Rare-earth minerals get rarer IE4 low-voltage motors based on the traditional AC induction squirrel-cage design—most commonly referred to as PMSMs—have been heavily dependent on REMs like neodymium and dysprosium, which are needed for the high-powered magnets that generate motor efficiencies above IE3 and NEMA Premium. PMSM motor manufacturers experienced a significant setback in prior years due to REM export caps imposed by China, the world’s leading producer and processor of these minerals, which caused neo-magnet prices to skyrocket in 2011. Some degree of stabilization has occurred as of mid-2012, but prices still remain high and represent a cost concern that motor manufacturers must pass on to their customers. Magnetic repulsion “Similar to the samarium cobalt (SmCo) magnet sourcing scarcity of the 1980s, which hastened the development and introduction of neodymium magnets to the marketplace, China’s tightening of its grip on REM exports has caused manufacturers to seek alternative IE4 technologies,” said Mark Meza, analyst with IHS. “Manufacturers have been very creative in dealing with magnet sourcing issues by producing drive technologies that reduce the number of neodymium magnets needed in a PMSM motor, or by producing IE4 class motors that use no magnets.” ABB’s Synchronous Reluctance motors and Nidec’s Switched Reluctance motors are two examples of low voltage motors that achieve IE4 levels of efficiency without the use of magnets, and have become viable lower-cost alternatives to the traditional neo-based PM machines. While ABB has introduced a new technology, switched reluctance technology has been around for a while, but is being given a fresh look and a broader application horizon in an industry promoting energy efficiency. Proprietary solutions “When discussing the industrial IE4 motor market in the past, the landscape was mostly limited to neo-based PM motors, or motors with copper rotors,” Meza added. “Now, several proprietary designs that use traditional ferrite magnet technology must be included in the discussion as well.” US-based NovaTorque produces an electrically commutated PM (ECPM) IE4 motor using traditional ferrite magnets, while Hitachi Metals Ltd. has been at the forefront of developing an axial flux motor technology using amorphous metal ribbons made of iron, silicon and boron (FeSiB), coupled with traditional ferrite magnet technology to achieve an IE4 level of efficiency. “There are always application-specific pros and cons when considering the most appropriate motor technology to use. But in an energy-conscious world, having more alternatives, and at lower cost, will only help the industry,” Meza said. Currently, most IE4 class motor product lines are limited to the 1-5HP power ratings. However, as industry acceptance increases with more affordable manufacturing cost structures, higher power-rated IE4 motors are expected to gain more traction in the marketplace.