Comparison of Power Converters for LED Illuminants

The purpose of the paper is to investigate the various modulation types for control of transformerless non-dimmable AC/DC/DC converters in nominal operation mode intended for LED illuminants. A combined PWM (pulse width modulation) is investigated. The optimal selection of power converter inductor core is considered. The derived results lead to conclusions for improvement of the power converter characteristics. Furthermore, the DC link capacitor is reduced without significant effect on circuit performance. It is proven that utilizing combined PWM would result in less current ripple and improved power factor. Utilization of nanocrystalline materials additionally reduces losses in the examined power converter.