Fractional order PID controlled phase shift modulated interleaved Watkins–Johnson converter-based LED driver with reduced current ripple

Abstract

This paper presents the design and implementation of an LED driver utilizing an interleaved Watkins–Johnson converter (ILWJC). ILWJC is proposed for the control of LED system. The converter's architecture, incorporating multiple phases with diodes, switches, and coupled inductors, allows for efficient voltage transformation and precise current control. Its interleaved configuration minimizes current ripple and enhances performance efficiency, ideal for applications demanding strict current regulation. This research, employing MATLAB's SIMSCAPE for simulations, focuses on a 12-V, 2.4-W chip-on-board injection type LED module. The study assesses the performances of proportional–integral–derivative (PID) and fractional order PID (FOPID) control systems in managing the ILWJC, with the FOPID controller showing superior outcomes in terms of faster response times, reduced steady-state error, lower peak overshoot, and improved voltage and current ripple control. These results underline the FOPID controller’s potential to enhance responsiveness, accuracy, and stability in LED lighting systems. The research also identifies an optimal phase shift for interleaving at 240 degrees, achieving the lowest current ripple at 63 mA, thereby enhancing conversion efficiency. A 12-W LED driver was successfully implemented in hardware, demonstrating the practical viability of the ILWJC for real-world applications.