A novel ZVT AC/DC converter with high power factor

In order to suppress mains harmonics in commercial ac lines, the guidelines on the maximum limit of the harmonic distortion is indicated by the Ministry of International Trade and Industry of Japan, and the measures have been taken for each individual apparatus. Also, the international standard IEC61000-3-2(the 2.1(st) edition) has defined the limit value for mains harmonic currents was newly enacted in October 2001. This paper presents a novel zero voltage transition converter, which functions as an active filter. The proposed circuit can cover wide range of ac voltage, and high power factor of about 0.93 can be obtained. It is simple and the cost is relatively low. Moreover, it has ZVT (Zero Voltage Transition) function, and is therefore very efficient. This paper describes the principal of operation, operating characteristics, and the suppressing effect for mains harmonic currents.