Three-phase resonant DC converter for TWTs

Power sources for traveling wave tubes (TWTs) are typically two types of square wave power converters. The first type is a current fed chopper used for space flight applications. The second is the more economical quasi-square wave pulse width modulation switcher for ground based applications. Both designs have been used with good results for the last thirty years. Electronic power conversion has made significant progress in the last decade. Three-phase resonant conversion, as described in this paper, is now the power converter of choice in the thin film plasma industry where low stored energy is required, to avoid arc damage to the TWT. For this application, more three-phase resonant power converters are sold than square wave converters due to their exceptionally low stored energy.