A novel PWM scheme for single-phase three-level power-factor-correction circuit

This paper presents a control scheme for a single-phase ac-to-de converter with three-level pulsewidth modulation. A single-phase power-factor-correct ion circuit is proposed to improve the power quality. The hysteresis curren t control technique for a diode bridge with two power switches is adopted t o achieve a high power factor and low harmonic distortion. A control scheme is presented where the line current is driven to follow the reference sinu soidal current which is derived from the de-link voltage regulator, the cap acitor voltage balance compensator, and the output power estimator The bloc king voltage of each power de,ice is clamping to half of the de-link voltag e. The high power factor and low current total harmonic distortion are veri fied by software simulations and hardware tests.