Fully high temperature superconducting (HTS) machine for future electric aircraft

Because of zero resistance and diamagnetism, superconductors were more than just perfect conductors comparing to conventional conductors. Superconductors have an excellent potential for power applications use; one of the exciting areas is the superconducting machine. After hundreds of years of development, the superconducting machine’s research entered into a new era since high-temperature superconductors’ discoveries in 1986. Many pioneering works have been done by researchers worldwide. They would push the high temperature superconducting machine in commercial use for future aircraft, offshore wind generator and all-electric ship propulsion. For high power applications, superconductors can provide significantly higher current density compared to copper. The superconducting machine’s design is more efficient and has potential use in MW-class wind turbines and future electrified aircraft. Furthermore, since 1986 when HTS were discovered, much progress has been made towards making the HTS applications economically feasible due to critical temperature above 77 K. The cost of cryogenic systems significantly decreased by using liquid nitrogen. In this thesis, the work focusses on pushing the HTS machine towards commercialisation use in power applications by focussing on AC loss studies on both rotor and stator of an HTS machine. In an AC machine design, AC loss’s Joule heat needs to be accurately identified and minimised. Which can improve the stability of the machine, and also reduce the cost of the cryogenic system. On the other hand, in rotating electrical machines, AC loss is unavoidable. We must identify the AC losses in both the rotor and stator part, which are the crucial parts in future large scale machine design. To this end, in this thesis, the contribution of original new works includes: 1. Developing, validating a 10 kW fully superconducting machine prototype platform to provide a machine environment to measure AC losses of HTS windings. 2. Calorimetrically quantify the electrical HTS stator and provided data for cutting edge AC loss reduction technologies. 3. Characterisation of NI superconducting coils in the machine rotor parts design. 4. More superconducting machine design considering power electronics.Because of zero resistance and diamagnetism, superconductors were more than just perfect conductors comparing to conventional conductors. Superconductors have an excellent potential for power applications use; one of the exciting areas is the superconducting machine. After hundreds of years of development, the superconducting machine’s research entered into a new era since high-temperature superconductors’ discoveries in 1986. Many pioneering works have been done by researchers worldwide. They would push the high temperature superconducting machine in commercial use for future aircraft, offshore wind generator and all-electric ship propulsion. For high power applications, superconductors can provide significantly higher current density compared to copper. The superconducting machine’s design is more efficient and has potential use in MW-class wind turbines and future electrified aircraft. Furthermore, since 1986 when HTS were discovered, much progress has been made towards making the HTS applications economically feasible due to critical temperature above 77 K. The cost of cryogenic systems significantly decreased by using liquid nitrogen. In this thesis, the work focusses on pushing the HTS machine towards commercialisation use in power applications by focussing on AC loss studies on both rotor and stator of an HTS machine. In an AC machine design, AC loss’s Joule heat needs to be accurately identified and minimised. Which can improve the stability of the machine, and also reduce the cost of the cryogenic system. On the other hand, in rotating electrical machines, AC loss is unavoidable. We must identify the AC losses in both the rotor and stator part, which are the crucial parts in future large scale machine design. To this end, in this thesis, the contribution of original new works includes: 1. Developing, validating a 10 kW fully superconducting machine prototype platform to provide a machine environment to measure AC losses of HTS windings. 2. Calorimetrically quantify the electrical HTS stator and provided data for cutting edge AC loss reduction technologies. 3. Characterisation of NI superconducting coils in the machine rotor parts design. 4. More superconducting machine design considering power electronics