Impact of IGBT behavior on design optimization of soft switching inverter topologies

A detailed examination of the factors that affect the design of resonant DC link inverters using IGBTs (insulated-gate bipolar transistors) is presented. A detailed design of a 50 kVA IGBT-based resonant DC link inverter is used as a design example. Measured loss data for IGBTs operating under zero voltage switching conditions are provided, and various loss mechanisms are identified. An approach that includes measured device characteristics in the converter design optimization process is proposed. The suitability of the resonant DC link inverters in view of better device understanding is also addressed. It is shown that performance of this family of power converters can be substantially improved by properly choosing the resonant components for a desired link frequency. Under such criteria, loss calculation and comparison with the family of PWM (pulse-width-modulated) VSIs has highlighted the fact that the resonant link inverter can offer a far better performance in terms of device loss reduction with a moderate peak voltage stress (K) of 1.3 or 1.4