A passively clamped quasi resonant DC link inverter

This paper proposes a passively clamped quasi-resonant DC link power converter topology which adds a small switched inductor to the conventional passively clamped resonant DC link inverter. The problem with high voltage stress in the conventional inverter is resolved, while its ruggedness, reliability and high power handling capability are preserved. The device voltage stress can be reduced from 2 per unit to 1.1-1.3 per unit, and PWM operation and link resonance control become easily fulfilled. Analysis and simulation have demonstrated the successful operation of the new topology. The introduction of the auxiliary switched inductor circuit is also well justified by its requirement of components with low stresses and ratings. Application of the quasi-resonant inverter is aimed at those requiring high power, high efficiency, low EMI and a high quality spectrum