Practical Implementation and Comparative Analysis of SPWM Techniques Using Fuzzy Logic Control on FPGA-Based Seven-Level Inverter for Power Quality Enhancement

This paper practically implements and compares different Sinusoidal Pulse Width Modulation (SPWM) techniques on a grid-connected seven-level Cascaded H-Bridge Multilevel Inverter (CHBMLI). The implementation is performed using Intel MAX 10 FPGA technology. A Zero Crossing Detector (ZCD) with hysteresis and Phase Locked Loop (PLL) realized within the FPGA is used for grid synchronization. A further expansion applied the Fuzzy Logic Controller (FLC) for control of power injected into the grid, thus reducing THD in total and improving the quality of power. Finally, the paper prescribed vigilance to SPWM techniques including Phase Shifted PWM (PSPWM), Phase Disposition PWM (PDPWM), Phase Opposition Disposition PWM (PODPWM), Alternate Phase Opposition Disposition PWM (APODPWM) and Saw-tooth Rotation PWM (SRPWM). PSPWM technology combining fuzzy logic control processes emerged with the least current THD and enhanced power qualities thus recommended for application in microgrid applications.