A design concept of DC filters for magnet power supplies

Passive filters are essentially used for attenuating current/voltage harmonics generated from pulse-modulation type converters which are prevalent in high-power magnet power supplies (MPS). But the passive filter limits the operation range of the output DC current, causes harmful filter resonance, and makes the system equation more complicated. This paper presents, a systematic and simple filter design method which considers not only filtering but also controlling the magnet current. The design algorithm is extended to the applications on superconducting magnetic energy storage (SMES) systems.