System Impedance and High-Speed Transient Behavior of the Alcator-C Magnet-Power-Supply System

摘要

The commutation inductance is one of the parameters which determines the voltage regulation, ac bus notch depth, inversion margin angle and converter conduction mode for the TF power supply. It was felt that measuring the actual commutation inductance would provide valuable information on this parameter and a chance to become familiar with the details of the Alcator power supplies. Although initial work indicated that the commutation inductance varied during an Alcator experimental run, the measurements reported here show the inductance to be almost constant. While measuring the commutation inductance, two seemingly unrelated phenomena were observed; lightly damped ringing in the commutation notches and growing oscillations of the alternator voltage envelope. Theoretical models and simulations have been developed to explain the ringing and envelope oscillations. Two possible methods of damping the resonance (and thus eliminating the ringing and envelope oscillation) are proposed and the relative merits of each solution have been outlined. (ERA citation 09:001671)