Digital Bridgeless PFC Converter with No Input Voltage Sensing and Lossless Current Measuring

摘要

This paper presents a digital controlled bridgeless PFC converter. Bridgeless PFC converters canrnachieve higher efficiency than conventional CCM PFC because of reduced conduction losses.rnHowever, since boost inductor lies in ac side, there are some difficulties in control of such circuit.rnInductor current measuring and input voltage sensing are two main issues. Usually, current measuringrntechnique is either very expensive or with loss, and the input voltage sensing is also more complicatedrnthan the conventional PFC converter. In this paper, a new cost-effective lossless current measuringrnmethod is adopted to reduce the power loss because of current sensing. To further reduce therncomplexity of the system, a control scheme that does not require input voltage sensing is applied, andrna simple 8-bit micro controller is used as digital controller. Experimental results show that PFC isrnsuccessfully achieved with the proposed cost-effective system.