Risk Mitigation in the Development of a Roebel Cable Based 1 MVA HTS Transformer

AbstractProgress is reported on the development of a 3-phase 1 MVA 11kV/415V HTS transformer using Roebel cable for the secondary windings. We describe efforts to address risks associated with short circuits, insulation, and heat transfer. We present modelling results for the response of the windings to a short circuit. Sample strands have been tested to demonstrate that cables immersed in liquid nitrogen can survive short circuits. The primary windings use insulated conductor to withstand computed impulse voltages. Breakdown and partial discharge testing confirms that the production insulation scheme is adequate for our design. Heat transfer results are presented for a sample Roebel cable windin