A ZERO-VOLTAGE-SWITCHING CONTROLLED HIGH-POWER-FACTOR CONVERTER WITH ENERGY-STORAGE ON SECONDARY-SIDE

The proposed high-power-factor converter is constructed with a flyback converter, and locates the energy-storage capacitor on the secondary side of the transformer. A high power-factor can be obtained without n eeding to detect any current, and the ZVS operation can be achieved wi thout auxiliary switches. To make the best use of these advantages in the converter, ZVS operations and power-factor characteristics in the converter were analyzed. From the analytical results, the effective co ntrol method for achieving ZVS was examined. Using a bread-board circu it controlled by this method, a power-factor of 0.99 and a conversion efficiency of 88% were measured.