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AC & DC Drive, VFD Panels

OM has long history of co-operation with utilities and OEM's to design potential transformer for generator exciter applications.

Exciter OEM's relay on us to design transformer that address the issue of aaplication heating from harmonics, field forcing conditions. And high available short circuit forms the generator bus. We often work directly with utilities on ppt retrofit project that require electrical design expertise and matching of dimentions and termination locations.

OM also provides drive isolation transformer for variable speed drive applications. There units called push transformer. These transformer are designed specification for the inherent harmonics, minimal space, requirement other unique characteristics of drive systems. Our experience includes winding 12, 18 and 24 pulse applications the frequency inverters.

The OM series transformer are designed to reduce the harmful harmonic currents produced by pulse parallel input rectifier circuit such as those used in adjustable speed or variable frequency(VFD) drive and 3 Phase computer or other electronic equipment. 6 Pulse rectifier circuit generate significant amounts of low frequency harmonic current if not suitably treated, these harmonics can have many undesirable effects these include.

1) Overheating of transformer cables and other electrical distribution equipment.
2) Poor power factor and premature failure of power factor correction capacitors.
3) High voltage distortion which can cause operational problems and/or component failure in the asd's themselves or other equipment connected to the same distribution.

The symmetry of the transformer is a major factor for reducing the harmonic on the medium voltage line the5th, 7th, 11th, 13th, 17th, and 19th Current harmonic are practically nonexistent as they have been cancelled by the shifted transormer winding.