Magnetic support for TGC

An adapted version of one of their range of magnetic bearings has been supplied by specialists SKF for Turbo Genset's latest offering, a 1.2 MW high speed generator powered by a gas-fired microturbine.

Magnetic bearings are highly suited to applications of this kind, that is to say, high speed non-load bearing locations where reliability and negligible wear is at a premium. The main features of a magnetic bearing are oil-free operation, no wearing components, virtual freedom from maintenance, freedom from vibration effects, and low energy consumption. Recent developments in this type of bearing technology, primarily of a smaller control system with improved performance, have widened the field of applications.

The bearing stator which provides the levitating field comprises a stack of laminations with copper coil windings; current passed through the coils generates magnetic poles that attac the shaft, causing it to move into a suspended position. A series of sensors allows the position to be calculated continuously, so that the controller can send adjusting currents to the coils that keep the shaft centrally positioned. Usually there is a 0.5 to 2 mm air gap between stator and shaft.

The 1.2 MW Turbo Genset system is due for market launch in the second quarter of 2005, following field trials currently taking place in combined heat and power applications.