Investigation on Time-Varying Behavior of NI HTS Field Coil for Synchronous Motors Considering Armature Reaction and Slotting Effect

This paper presents calculation results of time-varying behavior of no-insulation (NI) high temperature superconductor (HTS) field coil for synchronous motor considering armature reaction and slotting effect. We selected four NI HTS motor models having different stator topologies for confirmation of armature reaction and slotting effect. Also, before NI behavior analysis, we proposed a wound field synchronous motor (WFSM) dq-equivalent circuit which can be considered as a circuit model of insulated (INS) HTS motor. The circuit model used in this paper contains parameters varying with the position of rotor and dq-axes cross-coupling inductance for describing the armature reaction and slotting effect of practical motor. Next, to investigate time-varying behavior of NI field coil during steady-state operation, simulations of a new circuit model combining proposed dq-equivalent circuit and N…