Design of electromagnetic vibration test bench for maglev superconducting magnets

The research progresses of test benches of the wheel-rail train, electromagnetic suspension train, superconducting pinned suspension train, and superconducting electrodynamic suspension train were reviewed. The spatial magnetic field distribution on the superconducting coil side generated by the propulsion coils and levitation coils of the superconducting electrodynamic suspension train was analyzed. The overall solution of the electromagnetic vibration test bench for superconducting magnets was proposed, and the excitation module serving as the subsystem, and the converter system were introduced, which were core components of the electromagnetic vibration test bench. In addition, a multi-frequency composite current closed-loop control strategy for the converter system was proposed. The background spatial magnetic field, electromagnetic load, and vibration acceleration response of superconducting magnets under online operation and offline electromagnetic vibration simulation were simulated and compared. Research results indicate that the main spatial harmonic magnetic field orders of the propulsion coils and levitation coils are the second and the fifth, respectively. Correspondingly, they cause electromagnetic force fluctuations in the third and sixth harmonic frequencies of the superconducting coils. The current control strategy can achieve the control of the 24-phase excitation modules direct current, as well as third and sixth harmonic frequencies currents. The main electromagnetic loads obtained by the electromagnetic vibration test bench are consistent with the actual operating conditions. Specifically, the steady-state propulsion force error is no more than 3.4%, the steady-state levitation force error is no more than 8.0%, and the torque errors of the main third and sixth harmonic frequencies are no more than 6.5% and 8.5%, respectively. The trends and amplitudes of online operation values and offline simulation values of acceleration responses of each observation point of the superconducting magnets are basically consistent. It can be seen that the test bench can well reproduce the background magnetic field, electromagnetic load, and acceleration response of the on-board superconducting magnets in the actual operating environment, and the effectiveness of the overall solution has been verified.