Brushless PM motors boast energy efficiency
April 9, 2012
NovaTorque, Inc. (www.novatorque.com) a Sunnyvale, CA based producer of high efficiency, cost effective, permanent magnet motors, introduces its next generation design of 3hp and 5hp PremiumPlus+ motors. NovaTorque’s Gen2.0 PremiumPlus+ brushless permanent magnet motors, driven by variable frequency drives, boast motor-only rated point efficiencies of 93% and 92% for 3hp and 5hp versions respectively, far exceeding the levels achieved with induction motors. By comparison, 3hp and 5hp NEMA Premium induction motors, when driven by variable frequency drives, achieve a motor-only efficiency of between 88.5 and 90%.
“In addition to having higher efficiency at the rated point, NovaTorque’s PremiumPlus+ motors maintain their high efficiency over a much wider speed and load range. For example, in a variable speed, variable torque application such as a fan or pump, a 50% reduction in speed results in a 75% reduction in load. At that reduced load, NovaTorque motors will maintain efficiency of approximately 91%, whereas a NEMA Premium efficiency induction motor will have declined to 80%. The advantage is even more dramatic when compared to the current installed base of induction motors, where improvements ranging from 20% or more are achievable,” says Scott Johnson, NovaTorque’s Vice President of Sales.
Importantly, due to its unique patented flux-focusing stator and rotor hub geometry, the NovaTorque motor produces this performance with an all-ferrite (versus rare earth) magnet design.
“The cost of rare earth (neodymium) magnet material, the basis of most conventional permanent magnet motors, has risen dramatically and is now more than 25 times the cost of ferrite. Further, supply of rare earth magnets, nearly sole-sourced out of China, is increasingly uncertain. The ability to use ferrite magnets allows NovaTorque to price its motors comparable to induction motors. This means OEMs and HVAC systems builders can now economically deliver permanent magnet motor efficiency with their systems” explains Johnson.
NovaTorque PremiumPlus+ motors are packaged in standard NEMA frame sizes and mounting dimensions for easy substitution. Due to their high power density, NovaTorque motors are available both in the mounting frame size typical for induction motors, as well as one frame size smaller. NovaTorque PremiumPlus+ motors are compatible with readily available variable frequency drives (VFDs) from most leading manufacturers, including ABB, Yaskawa, Mitsubishi, Fuji, Hitachi, Toshiba and others.