Multi-stack Roebel conductor for large generators - has transposition between stacks on end winding overhang changing left hand stack to right hand stack at coil nose

摘要

On large, heavy current machines with wide slots employing Roebel transposed conductors with two or more stacks in parallel it is necessary to introduce compensation for the effects of radial fields in the end winding region. This may be achieved by conventional Roebel transposition of each individual stack in the slot portion, the stacks lying side by side, and then forming a Roebel transposition between stacks on each end winding. Thus the left hand stack (2) in the slot becomes the right hand stack (2') at the coil nose. With a correctly laid out winding the effect of radial fields is compensated and each individual stack can be short circuited with its neighbours at the phase ends without serious circulating currents arising. At the same time the length of the end winding overhang is not increased.