The Kyushu University Advanced Electric Propulsion Flight Body Research Center announced on June 7, 2023, that they have successfully conducted the world’s first rotational test of a fully superconducting motor for next-generation aircraft. This motor has achieved superconductivity not only in the field winding of the rotor but also in the armature winding, utilizing a cooling system that circulates liquid nitrogen with a pump.

With the target of achieving practically zero CO2 emissions in aviation by 2050, there is a strong focus on improving efficiency. The development of next-generation aircraft involves driving the motor using power generated by a gas turbine and generator, which in turn rotates the fan to generate propulsion. In light of these circumstances, the development team has been actively working on the development of a high-efficiency and high-power electric propulsion system using superconducting technology.

When a motor is superconducting, it becomes possible to achieve a ten-fold reduction in weight and double the output compared to conventional motors of the same size, thanks to the use of thin superconducting wires wound in the winding and the elimination of iron cores. However, superconducting wires exhibit specific AC losses during AC operation.

To address this issue, the team applied prediction, reduction, and high-current capacity technology to the AC losses of the superconducting wires they have been developing. This led to the successful development of a fully superconducting motor with all components utilizing superconductivity. Furthermore, they achieved the world’s first rotational test of a 400 kW-class fully superconducting motor for next-generation electric aircraft.

Moving forward, the team will continue the development efforts towards practical implementation. Additionally, they are aiming to apply this system to flying cars in the future.