Tapped-Inductor Converter as an Alternative of Conventional Flyback LED Driver: A Comparative Evaluation

When the two-winding transformer of a flyback converter is replaced by a single-winding auto-transformer or a tapped-inductor, it is called a tapped-inductor converter. Tapped-inductor driver is a prospective alternative to the conventional flyback driver in high-power LED lighting applications. This study compares a tapped-inductor driver, and a flyback driver designed for the same input-output conditions based on circuit efficiency, input power factor, input current THD, light flicker, and current control accuracy. A 60 W LED module, dimmable over (10–100) % range, is considered as the electrical load. Results obtained from Simulink simulation suggest that the tapped-inductor driver can perform considerably better than the flyback driver, and it is a more economical option. However, the main disadvantage of tapped-inductor driver is the absence of galvanic isolation, which may cause electrocution to a person touching the LED. Therefore, a residual current detection and elimination scheme is essential in the tapped-inductor driver circuit prior to commercialization.