Flywheel-type uninterruptible power supply using high temperature superconducting induction machine

Abstract The characteristics of fly-wheel (FW) type uninterruptible power supply (UPS) using superconducting induction machine (SIM) are experimentally and analytically studied. It is shown that a UPS can be realized using a SIM combined with a FW. The SIM has no electric connections to the outside of the rotor. Electrical power to the load is sustained even when the power from the line is lost, due to the trapped magnetic flux in the superconducting rotor windings. When line power returns, the SIM-FW-UPS recovers stand-by mode automatically, without the use of devices for synchronization to the power line frequency. Making a small-scale test model of SIM, the basic characteristics of the SIM are experimentally investigated. A numerical simulation is conducted to study the dynamic characteristics of 3MW SIM-FW-UPS using a simulation software to investigate feasibility of application of the system for industrial use.