Enhancing Range of Transmittable Power by Introduction of Double Damper Superconducting Generator into Long-Distance Power Transmission

To realize carbon neutral society, introduction of renewable energies in power systems has been promoted. As the number of inverter-based resources for photovoltaic (PV) and wind power generation increases and they replace synchronous generators, reduction of synchronizing power and resultant decrease of power system stability have been concerned. Meanwhile, superconducting generators (SCGs) with high temperature superconductors cooled by liquid hydrogen have been actively studied in Japan. SCGs are prospected to provide large synchronizing power owing to low synchronous reactance. In this paper, enhancement of synchronizing power by introducing double damper SCGs is discussed. For evaluation of synchronizing power, range of transmittable power and critical clearing time were investigated in a long-distance double-machine system through electromagnetic transient analyses. Double damper SCGs with machine constants differently designed in a current project were examined along with a single damper SCG designed in a previous project. Results showed that large synchronizing power of double damper SCGs enhances transmittable power range and critical clearing time, and thus double damper SCGs are able to offer flexibility to deal with wider variety of power flow changed by renewable energies.