Analysis of Different Control Techniques for Improved Power Factor and Reduced THD on Three Level Full Bridge AC-DC Converter

Abstract

This paper deals the three level full bridge power factor correction (PFC) converter in terms of power quality parameters like source current THD (Total Harmonic Distortion) and input power factor at different values of loading conditions and various values of supply voltage conditions by implementing the different closed loop control techniques. In this work, two different control strategies are implemented with cascaded control loop structure. Simulations are done with Simulink in Matlab with two different voltage and current controllers such as Sliding Mode Controller (SMC) and Average Current Control (ACC) to achieve converter performance in efficient manner. In SMC, sliding coefficients are calculated with limited bandwidth of upper and lower region and genetic algorithm is used to tune the two inner loop PI controllers in ACC. Comparative analysis is done with the parameters of power factor and THD. Also steady and transient parameters is evaluated and presented under wide range of line and load variations. From the comparative results, average current control technique gives better power quality parameters than the SMC. Average current control technique which improves the power factor with value of 0.993 and THD of 0.12% for presented converter. Power factor and THD is maintained in standard level even under variations occur in line and load side.