Superconducting generator modeling by iterative T-network equivalent circuits for investigation of transient performance

Novel iterative T-network equivalent circuits are derived for the direct and quadrature axes of a generator with superconducting field winding and stator air-gap winding. They enable the treatment of the complex skin effect phenomena in a multi-shell damper system for any nonperiodical time variation as well as of the mutual inductive couplings of the various rotor damper cylinders and the field and stator windings. Consisting of linear RL networks, similar to the equivalent circuits of conventional generators, they can be included in existing computer programs for power system and machine dynamics. In this way an efficient tool is obtained to analyze the transient performance of a superconducting generator in the power system, including the torsional behavior, flux density distribution in the superconducting field winding and design optimization of the damper system