Design and Development of DC DC Converter with Robust Control for Light Emitting Diode Lighting Applications

Abstract

In recent years, power electronic converter fed light emitting diode (LED) lighting newlinehas become most attractive. The LED driver is required to maintain the illumination newlineduring the variations in input voltage and current. In this research work, LED load newlinemodelling and design of a modified H-bridge converter (MHBC) has been examined to newlinefeed power to an LED load with 30 V, 0.7 A rating. The detailed analysis on modes newlineof operation, selection of most appropriate control for wide input variations, parasitic newlinemodel of the converter for the open loop system are carried out. The state space model newlineof the modified H bridge converter is derived and the performance analysis is carried out newlinefor wide input voltage range (24 V to 48 V). The developed system holds good for the newlineopen loop model of the plant and the performance deteriorates when the input voltage newlineis subjected to change during cold cranking operation. Hence, a closed loop controller newlineis designed to regulate the output voltage under variation in input voltage. newlineThe small signal model of the MHBC is developed and type II, type III and PI newlinecontrollers are designed to regulate the output voltage for variation in input voltage. newlineAmong the designed controllers, PI controller with stability boundary locus tuning newlinemethod yields better time domain performance. The experimental setup is developed for newline21 W LED load and tested with dSPACE1103 controller. newlineThe system parameter uncertainty in the LED lighting applications requires a robust newlinecontrol to improve the system performance. A closed loop robust PI controller newlineis designed for variation in input voltage and converter parameters for a 30 V, 0.7 A newlineLED load. The dynamic behaviour of the converter is analysed by deriving the small newlinesignal model with perturbed state variables. The robust PI controller is designed using newlineKharitonov s sixteen plants theorem by considering the parametric uncertainty. The newlineperformance of the system is studied in MATLAB simulation and validated in real time newlineusing dSPACE1103 controller for various input voltages. A