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Abb Acquires New Zealand Business To Expand Power Electronics Portfolio

Vectek’s innovative technology helps improve power quality for industry

Zurich, Switzerland, May 5, 2008 – ABB, the leading power and automation technology group, has acquired the business of Vectek Electronics, a New Zealand company with innovative technology that improves the quality of the power supply in industrial installations, which helps to reduce downtime and increase productivity.

Harmonics And Vfds

One of the areas that I operate in, has a high density of VFDs on pumps on relatively weak supplies. The result is that the high levels of harmonics on the VFD inputs has accumulate in the supply and is causing a high THD of the supply voltage. While we do have supply regulations covering harmonics, in this instance, the harmonics are higher than they should be.

There is an option of using zig zag transformers and six phase rectifiers as a means of reducing the harmonics drawn by drives however in this case, the drives are already installed.

There is a transformer for each drive and sizes range up to 200KW.

One thought that I had, was that for future installations, and there are new installations going in all the time, that the new supply transformers be designed with a zig or a zag winding to give a phase shift, and install equal loading on the leading and lagging phase shifts. This should act like a twelve pulse input on one drive, only it will be across two drives.

Any thoughts on this??

Best regards,