Design of a 10-MW-Class HTS Homopolar Generator for Wind Turbines

High-temperature superconductor (HTS) technology has been studied recently for the use with superconducting high-power transmission and distribution, motors, generators, and fault-current-limiting devices such as cables and transformers. HTS technology, which can provide a large electromotive force in a small area owing to its large current density compared to that of a normal conductor, can reduce the weight and loss of a generator when compared to the attributes of a conventional machine. Moreover, once the HTS conductor has stabilized, the challenge of cooling the windings in large-scale generators can be resolved. Therefore, the technology has been studied for application with 10-MW-class superconductor wind-turbine generators. Although an HTS conductor generator offering a higher torque density, lower weight, and higher efficiency than a conventional generator can be designed, the design must satisfy the requirements of the critical magnetic field, critical current, and critical temperature of the superconducting winding. The HTS homopolar superconducting synchronous generators have a simple structure with a fixed HTS conductor and are one of the most suitable types of generator that is able to satisfy these requirements more easily. In this paper, we propose a 10-MW homopolar-type wind-turbine generator.