The high precision calculation of the winding losses of the large electrical machines is a very important target, offering the possibility to increase the efficiency. Consequently, the electric machine working at lower temperature, the life time will be larger. Finally, the optimal efficiency design of the machine occurs. The second part of this work provides the strand currents that flow through the hollow subconductors of a Roebel bare, if the entire bare current is known.

Keywords: Hydrogenerator, Roebel bar, strand current distribution, optimization