In this paper, the application of a novel time-frequency analysis tool for the online estimation of the transfer functions of a notional high-temperature superconducting (HTS) marine propulsion motor is demonstrated. A detailed simulation model of the notional HTS motor with a realistic load modeling of sea states to produce torque oscillations is utilized for the analysis. A method is presented for the online near real-time estimation of transfer functions between the torque oscillations and the concomitant variations in the field current and mechanical speed of the HTS motor. The transfer functions, obtained by using the novel method, are compared with the results from a traditional offline transfer function estimation technique.
N. Senroy, S. Suryanarayanan, M. Steurer and S. L. Woodruff, "Adaptive Transfer Function Estimation of a Notional High-Temperature Superconducting Propulsion Motor," in IEEE Transactions on Industry Applications, vol. 45, no. 2, pp. 651-658, March-april 2009, doi: 10.1109/TIA.2009.2013548.
KEYWORDS: empirical mode decomposition (EMD); empirical transfer function estimation (ETFE); fast Fourier transform (FFT); high-temperature superconducting (HTS) motor; Hilbert-Huang (HH) method; Hilbert transform; intrinsic mode function (IMF); sea-states; ship propulsion.