Experiment Study And Analysis Of AC Losses Of SMES Magnet Applied In Power Network

Because AC losses of high temperature superconducting (HTS) tapes and coils have direct affects on the stability of HTS apparatus, investigation of AC losses of HTS tapes and coils has always been one of the most important research branches of HTS application and have important practical significance to promote development of superconducting power technology.Measurement of critical current is necessary to investigation of AC losses of HTS tapes and coils. Based on research of criterion of DC current, a design for test system of superconductor is proposed and this design is verified by actual test in this paper. The test system realizes the functions of real-time data collection and remote supervision in virtual instrument environment. Critical current of HTS tapes and coils have been tested in this test system to provide the reliable precondition for the measurement of AC losses.In order to realize a quick and accurate measurement of AC losses for HTS tapes and coils, the measurement principle of AC losses is systematically investigated in this paper at first. Based on advanced electrical method, experiment platform of AC losses for HTS tapes and coils has been established, which uses capacitance compensated method for the measurement of the AC losses in HTS coils. In addition, auto measurement of AC losses has been realized through remote control of Lock-in Amplifier in LabVIEW.Many HTS samples have been tested in test system of AC losses to obtain a lot of reliable experiment data. In this paper, theoretical model of AC losses of high temperature superconductors is introduced. The critical currents and AC losses of HTS tapes, stacked tapes, HTS coils, series HTS coils are investigated from the two aspects of theory and experiment. Meanwhile, the influence of frequency of AC transport currents on AC losses is studied.