Simple Digital-Controlled AC/DC Converter with Power Factor Correction for Universal Input Applications

A simple digital-controlled AC/DC converter with power factor correction for universal input applications is presented. The presented method provides the following features: (1). easy for digital implementation, (2). universal input applications, (3). high power factor, (4). fast dynamic response, (5). no need of circuit parameter in prior, (6). no need of input voltage sensor. The range of input voltage for the presented converter can be low line to high line, 90 V/AC to 264 V/AC. The special feature of the proposed AC/DC converter doesn't require AC input voltage sensor and thereby reducing the cost of A/D converter for digital control. An experimental system is set up which is controlled by digital controller. Experimental results for conventional average current mode control with input current sensor and the presented converter are presented for confirmation. The system specifications include: AC 90-264 V input, DC 390 V output, 500 W. Experimental results show that the presented digital-controlled AC/DC converter gives similar performance as that of conventional one while not requiring AC current sensor. The results meet IEC 61000-3-2 and the power factor is higher than 98% under full load condition for the universal input voltages.