Elimination of variable harmonics on motor generator circuit for experimental fusion facility

A special active filter, which can eliminate the variable harmonic currents in continuity, was investigated. A variable-frequency band-pass filter was developed for the extraction of current component of fundamental frequency. Dynamic simulations for the active filter, motor generator with a flywheel (FW-MG) and power supplies of heating devices for the experimental fusion device of LHD have been carried. We found that the harmonic currents with the amplitudes of 20% have been reduced to less than 2% in the operational frequency range from 95 Hz to 55 Hz by using this active filter.