Nov 16, 2009

Danfoss Launches VLT Low Harmonic Drive

Product designed to eliminate harmonic disturbances on the supply grid

Danfoss Drives introduced the VLT Low Harmonic Drive. VLT Low Harmonic Drives are designed to attack current distortion at the source by performing real time analysis and actively imposing currents, as needed, to restore and ensure quality sine waves from the power supply grid, according to the company.

Additionally, they feature a modular design meaning that most elements are produced in large scale for cost-effective production, said the company. Most VLT drives, including VLT Low Harmonic Drives, are individually configured according to the customer’s specific needs.

VLT Low Harmonic Drives share the same technology platform as Danfoss’ VLT high power drives, designed to deliver functionality, quality and reliability, while sharing many of the same features such as high energy efficiency, backchannel cooling and user-friendly operation, according to Danfoss. These drives are available in the power range 132 to 630 kW high overload, 160 to 710 kW normal overload and voltage range of 380 to 480 VAC, 50 to 60 Hz. They meet the IEEE519 recommendation, are available in an IP 21/NEMA1 or IP 54 (hybrid) enclosure, are UL, cUL and Ctick listed, and carry the CE mark.

“In essence, the filter portion of VLT Low Harmonic Drives has the same working principle as a set of noise canceling headphones, where the noise or distortion is measured and a computer phase signal is imposed to compensate for that noise,” said Gregers Geilager, product manager, Low Harmonic Drives. “As a matter of scale, noise canceling headphones can inject 100 mW at 50 to 1,000 Hz, where VLT Low Harmonic Drives can inject several hundred watts at 250 to 2,000 Hz.”