PROJECT TITLE :

A Single-Stage PFM-APWM Hybrid Modulated Soft-Switched Converter with Low Bus Voltage for High-Power LED Lighting Applications - 2017

ABSTRACT:

In order to style a high-efficiency price-effective high-power LED driver, one-stage integrated boost- LLC-type soft-switched ac-dc converter is typically employed. The minimized number of semiconductors and therefore the reduced power loss are its main benefits. However, the high bus voltage is its well-known disadvantage, which is caused by the utilization of a typical pulse frequency modulation (PFM) control strategy with the duty cycle of zero.five. The vary of the input ac voltage is severely limited. In order to beat this drawback, a hybrid PFM-uneven pulse width modulation strategy is proposed during this paper. The proposed strategy can significantly reduce the bus voltage whereas maintaining the soft-switching operation for both primary MOSFETs and secondary diodes. Furthermore, the electrolytic capacitors are removed by increasing the bus voltage ripple. Hence, high potency, long lifetime, low price, and universal operation are achieved on the proposed LED driver, that is well suited to the virtues of LED lighting supply. The detailed operation principles and design consideration for the proposed modulation approach are analyzed and mentioned. The feature of the proposed answer was demonstrated using a universal-input a hundred-W hardware prototype. The experimental results verified the full-vary zero-voltage-switching (ZVS) operation for primary switches and the efficiency achieved 91.half dozen% beneath the one hundred thirty-V input voltage.