Harmonic free rectification with unity power factor for multi-megawatt applications

A harmonic free regulated AC-to-DC power conversion using the sequential discharge rectification (SDR) topology, was first presented during the 14/sup th/ Power Modulator Symposium in June 1996. This topology has been modified to include a small high-frequency output transformer to permit DC generation over a large voltage range. The topology lends itself to operate directly off a 4160 V, 11 kV or 13.8 kV AC distribution line and draw a harmonic free input at unity power factor, complying with the IEEE 519-1992 and IEC 555-2 guidelines without the utilization of additional VAr capacitor or harmonic filters. The technology is based on the property of resonance circuit thereby permitting the use of soft switching and self-commutating low di/dt solid state devices. The switching characteristics permit the utilization of less expensive thyristors available in higher voltage, higher current and higher power ratios with lower conduction losses. This design is being proposed for a regulated 95 kV, 2 MW average klystron power supply.