Speaker
Description
A HTS linear synchronous motor (LSM) that uses YBCO-coated conductor as the secondary excitation system and double layer concentrated windings as the primary was recently demonstrated in our laboratory. Two YBCO-coated conductor racetrack coils were wound on a fiberglass frame via the epoxy impregnation technique and injected dc currents to provide a high stationary magnetic field for LSM. Thirty-nine copper racetrack coils manufactured modularly were assemblled into double layer concentrated winding to act as the primary of a 15-m long test line. Prior to assembling the whole system, we tested the current versus voltage curve of the connected YBCO coils with a four-proble setup, and the short circuit test and steady state test were processed on home-made electromagnetic force testing system to investagte the starting characteristics and back electromotive force of HTS LSM. Using a frequency converter to regulate the three-phase currents of stator, the secondary system could take a back-and-forth movement along the stator at electromagnetic clearances of ~50 mm. Dynamic measurements were carried out to observe the transient thrust and thrust fluctuation against the input current of the YBCO coils, clearance as well as the amplitude and frequency of the primary current. Moreover, we also established a finite-element model using which the transient thrust and thrust fluctuation at various speeds (up to 613 km/h) of the prototype were computed and found to be comparable with the measured dataset. This work has advanced the study of YBCO-coated conductor linear motor from the static measurements to the dynamic operation, taking a step forward to the application of such promising linear traction system of EDS train.
