High power motors: Nanocrystalline cores reduce over voltage

Nanocrystalline cores are designed for use in high power inverter systems and turbine generator drives. See photo.
By Control Engineering Staff February 12, 2009
Iron-based nanocrystalline is a soft, magnetic material that reduces build volume on ac and dc motors.
Iron-based nanocrystalline is a soft, magnetic material that reduces build volume on ac and dc motors. Source: MH&W

Mahwah , NJ –  MH&W International has introduced Magnetec Cool Blue nanocrystalline cores for use as common mode chokes to reduce the build volume of damaging motor bearing currents in high power inverter systems and turbine generator drives. Cool Blue cores also suppress asymmetrical EMI currents generated by the parasitic currents of motors and their cables. The result is increased service life of motor bearings, and reduced maintenance and stoppages, according to the company.
MH&W International Corp. provides magnetics solutions, including toroids and other products to the telecommunication and power supply industries. Cool Blue toroid cores are typically placed over the hot legs (L1-L2-L3) of a motor drive cable assembly. To serve as common mode chokes, one or more cores are placed over the connector cables in the DC-link as well as at the inverter output. Typical applications are on high power motors and wind power generating equipment. The cores are said to be easily adapted to retrofit maintenance operations, as well as to new installations.
Iron-based nanocrystalline is a soft, magnetic material that the company says provides performance superior to permalloys, ferrites and other materials when it comes to effectively reducing build volume on switched power converters and on ac and dc motors. Cool Blue cores provide a wide range of permeability, 25,000-90,000 at 10 KHz, and a saturation flux density of 1,200 mT.

MH&W’s Cool Blue nanocrystalline cores are available in a range of M-type sizes including both round and oblong shapes. The smallest core for high power motor applications has an outside diameter of 63 mm and inside diameter of 50 mm. The largest core has a 500 mm OD and 450 mm ID. The standard thickness of all Cool Blue cores is 30 mm. Prices start at $40 per piece for the 63 mm OD size in 100 piece quantities.

www.magnetec.mhw-intl.com

– Edited by Renee Robbins , senior editor
Control Engineering News Desk
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