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INTEGRATED MAGNETIC SLOT WEDGE

IP.com Disclosure Number: IPCOM000244160D
Publication Date: 2015-Nov-17
Document File: 2 page(s) / 33K

Publishing Venue

The IP.com Prior Art Database

Related People

Janne Roivainen: AUTHOR [+3]

Abstract

The current magnetic slot wedge design shown in Figure 1 has been in use for severaldecades During this time the electrical design of machines has become tighter meaningthat more and more power is taken out from same air gap area compared to the olderdesigns This has led to increased magnetic forces on wedges together with highertemperatures which results in reduced mechanical strength of resin Integrated magneticslot wedge can tolerate higher mechanical stresses and it also improves the electricalperformance characterises of a machine PERMEABLE MAGNETIC SLOT WEDGE RADIAL SLOT MOTOR GENERATOR ALTERNATOR

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INTEGRATED MAGNETIC SLOT WEDGE

Janne Roivainen, Pekka Kanninen, Tommi Ryyppö, all of ABB Oy Motors & Generators Helsinki

TECHNICAL FIELD

New design of an integrated magnetic slot wedge used in rotating electrical motors and generators especially for high voltage windings to keep coils of winding fastened in stator slot in reliable manner.

BACKGROUND OF THE DISCLOSURE AND TECHNICAL PROBLEM TO BE SOLVED

The purpose of the new slot wedge design is to increase the mechanical strength of the wedge and improve the machine electrical performance (better efficiency & power factor). The new design is suitable for all types of form wound coils.

The invention improves the mechanical strength of wedge and it also simplifies the assembly of windings & wedges when compared to traditional way shown in figure 1.

Figure 1. Coil assembled to slot having slot wedge installed before VPI (Vacuum Pressure Impregnation) treatment. There is a piece of slot wedge underfelt between wedge and coil.

SUMMARY

The current magnetic slot wedge design shown in Figure 1. has been in use for several decades. During this time the electrical design of machines has become "tighter", meaning that more and more power is taken out from same air gap area compared to the older designs. This has led to increased magnetic forces on wedges together with higher temperatures (which results in reduced mechanical strength of resin). Integrated magnetic slot wedge can tolerate higher mechanical stresses and it...