Product category: AC/DC Power Supplies
News Release from: Emerson Network Power Adaptive Power and Cooling | Subject: Liebert AF active filter
Edited by the Electronicstalk Editorial Team on 2 April 2007
Active filter eliminates harmonic distortions,
A new active filter, applied to non-linear loads, measures and eliminates harmonic distortions, preventing their transmission through the network
Organisations today are generally at a considerable degree of risk from incidents involving power supply inefficiencies that can jeopardise the integrity of critical loads and the continuity of business processes. Typical of these incidents is the growing issue of 'harmonic currents', which are anomalies generated by servers, PCs, static convertors and other loads that, absorbing power in 'non linear' mode, distort the normal sinusoidal curve of current and also reflect on voltage.
This article was originally published on Electronicstalk on 2 April 2007 at 8.00am (UK)
Related stories
Static switch handles interrupted power
The four-pole Liebert Hiswitch2 ensures maximum supply availability through automatic switching without any overlapping of the input sources
Chillers keep quiet about rack cooling
Air-condensed water chillers very produce very little noise, which makes them ideal for urban areas subject to strict acoustic pollution regulations
Harmonic 'noise' has several negative effects, in particular causing device overheating, interference with sensitive equipment, unexpected opening of differential switches, and oversizing of power connections.
Liebert AF, the new active filter designed by Emerson Network Power, responds effectively to this problem.
Applied to non-linear loads, this convertor measures and eliminates harmonic distortions, preventing their transmission through the network.
Elimination is achieved by generating harmonics with the same amplitude but opposite in phase, resulting in a stable and clean sinusoidal current.
The level of correction required by the distribution system is calculated according to two parameters, namely the 'total harmonic distortion of current' or THDI, and the power factor.
Located between the UPS and the source, for example a transformer or generator, Liebert AF reduces THDI significantly, bringing it down below 4% and stabilizing it independently of the load.
Whereas reducing the quantity of energy transmitted to the mains network, this solution also compensates the reactive power of non-linear loads and improves the power factor, allowing a small generator to be used for the same application.
The result is lower consumption and costs, and higher efficiency of the distribution system.
Easy and quick to install, up to six modules can be connected in parallel.
The Liebert AF can be combined with passive filters and is compatible with Liebert's monitoring products.
• Emerson Network Power Adaptive Power and Cooling: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
