High efficiency PFC converter to meet EN61000-3-2 and A14

The introduction of Regulation EN61000-3-2 a few years ago has forced power supply engineers to design AC/DC power converters that meet the limits imposed by it. As a consequence and considering that unity power factor is not required, many alternatives to the classical two-stage approach have been proposed reducing the cost of the power supply, especially in low power applications. The recent publication of the Amendment 14, that modifies the definition of the Class D of EN61000-3-2, may change the scope again. In this paper, a new AC/DC converter is proposed. This converter has been designed to improve the efficiency over the classical two-stage approach by improving the energy management. Thus, output power is processed 1.2 times instead of twice. Moreover, the voltage on the storage capacitor is not very sensitive to input voltage variations making the optimisation of the converter easy. The line current has been analysed and a trade-off between efficiency and distortion has been found.