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Permanent magnet motors `exceed IE4 efficiencies`
Published:  13 October, 2012

The motor-maker Regal has announced a range of permanent magnet AC synchronous motors that, it claims, out-perform the yet-to-be-implemented IE4 super-high efficiency standard. The SyMax motors are said to use about 30% less energy than high-efficiency machines meeting the Nema Premium standard.

Although the PM motors are more expensive than standard induction motors, Regal says that the price will often be recouped in two years or less, especially in high duty-cycle applications.

The high efficiency is achieved by eliminating rotor conductor losses, optimising the fan design, using precision-wound stators, and providing variable-speed operation. To maximise reliability and longevity, the SyMax motors have wider air gaps than usual. Low operating temperatures, high IP levels and precision rotor balancing also contribute to the motors’ reliability, while eliminating diecast components reduces noise and vibration levels.

The PM motors are said to deliver their high efficiencies over a wider speed and load range than many non-inverter-driven induction motors. This allows them to operate at the optimum speed for energy savings for an application, rather than having to match a machine’s speed to optimise efficiency. The motors are also said to offer improved speed and torque regulation, dynamic performance, and higher torque/current ratings for applications that need maximum system performance.

The SyMax motors can be used as direct drop-in replacements for existing induction motors, with the same footprint, shaft heights and other dimensions. The higher power density of the PM motors will typically allow a two to three frame reduction in size, while providing the same output torque. Alternatively, for the same frame size, more torque can be delivered.