Optimization Schemes for Soft-switching PWM Combined Three-level Converter

Soft-switching PWM combined three-level (TL) converters are very suitable for high input voltage with wide range applications due to the reduced voltage stress on power switches and reduced filter requirements. The converters include two transformers and have two operation modes, which provide possibilities to optimize the performance of the converters. This paper proposes some optimization strategies for the combined TL converters based on the control strategies and turns-ratios to achieve a better performance. Two prototype converters have been tested for the verification of the theoretical analysis.