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Danfoss Drives' VLT® Low Harmonic Drive

Article-Danfoss Drives' VLT® Low Harmonic Drive

Danfoss Drives' VLT® Low Harmonic Drive

The filter portion of VLT Low Harmonic Drives has the same working principle as a set of noise cancelling headphones, where the noise or distortion is measured and a computer phase signal is imposed to compensate for that noise. VLT Low Harmonic Drives don't merely reduce or mask current distortion; they attack it at the source by performing real time analysis and actively imposing currents, as needed, to restore and ensure the highest possible quality sine waves from the power supply grid. They are well suited for: meeting the toughest of harmonics recommendations/standards; installations that are generator-powered, or that have generator back-up power; soft power grids; and grids with limited excess power capacity. VLT Low Harmonic Drives feature a modular design meaning that most elements are produced in large scale for cost effective production - and are individually configured according to the customer's specific needs to deliver the value of a highly customized quality drive for the price of a mass produced unit. VLT Low Harmonic Drives cause no increased winding stress and have no impact on bearing life. They provide the user with a full readout of the unit performance towards the grid, including a graphical overview of grid behavior. Where the performance of other low harmonic technologies depend on the stability of the grid and load or affect the controlled motor, VLT Low Harmonic Drives continuously regulate the network and load conditions without affecting the connected motor. VLT Low Harmonic Drives are the only solution that can cut out the harmonic mitigation during drive operation and so reduce the energy consumption in cases where the drives do not need the harmonic reduction (at light loading). The result is lower power consumption and higher energy efficiency. A unique design uses a ducted back channel to pass cooling air over heat sinks with minimal air passing through the electronics area. This allows 85 percent of the heat losses to be exhausted directly outside of the enclosure, improving reliability and prolonging life by dramatically reducing temperature rise and contamination of the electronic components.

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