Active filter for high current dc magnets

Thyristor type regulated power supplies operated from 3 phase power lines are sensitive to phase unbalance, voltage fluctuations, line impedance and to other loads connected to the same line. At Fermilab, the large variety of pulsed equipment provides such perturbations in a wide frequency domain. A description is given of active filters used to stabilize magnet power supplies for a storage ring against fast fluctuations