Harmonic free new inverter topology for high voltage, high power applications

A new inverter topology well suited for high voltage and high power applications promises near harmonic free operation, low losses and high packing densities. The new inverter is based on standard thyristors for the switching using ´pulse frequency modulation´. This converter topology is being investigated for 20 MW ship propulsion system and yields a power density 5.5 MW/m/sup 3/ in comparison with 0.4 MW/m/sup 3/ for PWM converter with the same bi-directional functionality. Another major emphasis is the application of this converter topology for regulated high voltage DC voltage, such as for a 5 MW klystron power supply or a PFN charger. The key feature of this converter topology is the unique converter integration with a high frequency transformation stage. This permits a significant weight and volume reduction over other converter topologies and conventional power supplies. This paper specifically addresses the design for a 350 kW klystron power supply with an input of 480 V, 400 Hz with a regulated 50 kV DC output. The analysis of the inverter topology and the optimized magnetic components are presented.