Hyoungwoo Lim

Test of an induction motor with HTS wire at end ring and bars

Motors with HTS wires or bulks have been developed recently. These are a large synchronous motor with HTS wires at the field winding in the rotor, hysteresis and reluctance motors with HTS bulk in the rotor. This paper presents the fabrication and test results of an HTS induction motor. Conventional end rings and short bars were replaced with HTS wires in the motor. Stator of the conventional induction motor was used as the stator of the HTS motor. Rated capacity and rpm at full rotor of the conventional motor were 0.75 kW and 1710 rpm. Two HTS wires are used in parallel to make the end rings and bars. The critical current of the BSCCO-2223 HTS wire which was used in the bars and end rings were 115 A. An electrodynamometer was coupled directly to the shaft of the rotor with HTS wires.

Magnetization Loss and Shield Effect in Multi-Stacked Tapes With Various Stacking Configurations

AC loss is one of the major topics in large AC power applications using high temperature superconductor such as power transformers, transmission cables and fault current limiters because it is closely related to operation efficiency. Multi-stacked tape conductors should be used to transport the large current in those power applications. A research of various arrangements of HTS tapes for multi-stacked tapes has been performed to increase the capacity of transport current in HTS power applications. In this paper, we studied magnetization loss and shield effect from several different arrangements of BSCCO tapes such as Face-to-Face type, regular matrix type (mtimes2) and irregular matrix type. The results show that the magnetization loss of the Face-to-Face arrangement was lower than those of the other matrix types for the same stacking numbers. We think that the result was due to the shield effect by demagnetization of adjacent HTS tapes which were located as face to face

Properties of an HTS Magnet With Pancake Windings Excited by Multiple Power Sources

When the HTS magnet consisting of pancake windings is excited by a single power source, most of the pancake windings operate under their critical currents because currents of the entire pancake windings are limited by the critical current of the pancake winding which has the lowest critical current. By using multiple power sources, all pancake windings are able to conduct their critical currents. This paper describes the HTS magnet with pancake windings which are excited by multiple power sources. Critical current of each pancake winding is determined by using optimization technique. Fabrication of the BSCCO magnet consisting of 10 pancake windings is described and test results of the BSCCO magnet are given. The magnetic field and the perpendicular magnetic field of the magnet excited by multiple power sources are compared with those of the magnet excited by a single power source.

AC Losses of Pancake Winding and Solenoidal Winding Made of YBCO Wire for Superconducting Transformers

Pancake winding and solenoid winding are commonly used ones in superconducting power transformers. This paper deals with AC losses of the pancake winding and solenoidal winding made of YBCO wire. The pancake winding and the solenoidal winding which had same number of turns and diameter had been made and tested. Inner diameter and number of turns of both windings were 100 mm and 30, respectively. Pancake winding and solenoidal winding which were made of BSCCO wire were also fabricated and measured. Results of measurements were compared with the AC losses obtained by numerical calculation.

Effects of Hybrid Multi-Stacking of BSCCO Wires and YBCO Wires on AC Loss

The multi-stacked wires which are made of one type of wires, YBCO wires or BSCCO wires, are being currently used in superconducting machines. Property of hybrid multi-stacked (HMS) wire made of the combination of YBCO wire and BSCCO wire can be different from the uniform multi-stacked (UMS) wire. This paper presents the magnetization losses of HMS wires which were made of YBCO wires and BSCCO wires. HMS 2 stacked (YB) wire and HMS 4 stacked (YYBB, YBYB, YBBY and BYYB) wires were tested. Y and B stand for YBCO wire and BSCCO wire, respectively. The YBCO wire and the BSCCO wire which had similar width were chosen to fabricate the UMS wires and HMS wires. The losses of the HMS wires were compared with the loss of UMS wires. According to the measurement results of the HMS 2 stacked wire and HMS 4 stacked wires, the loss of HMS wire was between the loss of UMS BSCCO and UMS YBCO wire at low magnetic field and it was almost the same with those of UMS BSCCO and UMS YBCO wire at high magnetic field.