Comparative Study of PI, Fuzzy and Fuzzy tuned PI Controllers for Single-Phase AC-DC Three-Level Converter

Abstract

-This paper presents the design of closed loop controllers operating a single-phase AC-DC three-level converter for improving power quality at AC mains. Closed loop inhibits outer voltage controller and inner current controller. Simulations of three level converter with three different voltage and current controller combinations such as PI-Hysteresis, Fuzzy-Hysteresis and Fuzzy tuned PIHysteresis are carried out in MATLAB/Simulink. Performance parameters such as input power factor and source current total harmonic distortion (THD) are considered for comparison of the three controller combinations. The fuzzy-tuned PI voltage controller with hysteresis current controller combination provides a better result, with a source-current THD of 0.93% and unity power factor without any source side filter for the three level converter. For load variations of 25% to 100%, a THD of less than 5% is obtained with a maximum value of only 1.67%. Finally, the fuzzy-tuned PI voltage with hysteresis controller combination is implemented in a Xilinx Spartan-6 XC6SLX25 FPGA board for experimental validation of power quality enhancement. A prototype 100 W, 0-24-48 V as output converter is considered for the testing of controller performance. A source-current THD of 1.351% is obtained in the experimental study with a power factor near unity. For load variations of 25% to 100%, the THD is found to be less than 5%, with a maximum value of only 2.698% in the experimental setup which matches with the simulation results.

Power Quality Analysis of Single Phase Full Bridge Rectifier Fed DC Motor Drive

“…Luo topology of AC to DC conversion is used for power quality improvement with hysteresis controller to achieve high power factor along with supply current harmonic distortions of less than 5% [13]. THD analysis for various load conduction of AC to DC three level converter with a help of different controller tuners such as PI, Fuzzy tuned PI controller, the comparative results for each controller provides optimised result [11]. The presence of bulk capacitances and other filtering measures in diode bridge rectifier won't reduce lower order harmonics, and creates problem of low power factor at input AC side, thus, this can be eliminated by providing controllers such as proportional integral controller etc., Also the problem such as increased electromagnetic interference, losses due to distortion in line voltage can be appropriately minimized to a level [26].…”

Investigation of Power Quality Improvement in Super Lift Luo Converter

“…To prevail over these shortcomings, single phase rectifier with boost topology is adopted. In comparison to bridge rectifiers, the boost topology offers reduced supply current harmonics, improved input power factor and reduced filter requirements [4]. Even though, it offers lot of advantages it has its own drawback of high switching loss thereby efficiency gets lowered.…”