Influence of Coil Position on AC Losses of Stator Superconducting Windings of a Synchronous Machine for a 10 MW Wind Turbine

One of the main tasks during the design of a superconducting electrical machine is the estimation of losses in the superconducting coils. These losses can be decisive in such applications since they influence the cooling power requirements and the overall efficiency of the machine. In this article, we focus on the dissipation in the stator superconducting coils of a synchronous machine. The calculations are done within the framework of the SupraGenSys project, which aims to develop a new superconducting generator for the wind energy sector. A detailed study of the ac losses in the stator coils is carried out based on a basic design that considers the main constraints of this application. The objective is to look for an optimum solution for the level and distribution of losses as a second step in the design process. The T-A formulation of Maxwell's equations is used in a 2-D finite-element model to analyze the behavior of the magnetic field around the coils and calculate losses. Particular attention is given to the position of the coils inside a slot and several coil configurations are presented. It is shown that certain coil arrangements lead to a significantly lower total loss, a more uniform loss distribution, which ultimately leads to the possibility of increasing the operating temperature.