FPGA Implementation of 5-level Neutral Point Clamp Inverter

Abstract

Since multilevel inverters have complex switching schemes, it is an important requirement to generate fast and easy switching signals. FPGA has the feature of fast and parallel operation and has been widely used in the field of power electronics in recent years. In this study, a fast signal generation of Sinusoidal Pulse Width Modulation (SPWM) technique using Field Programmable Gate Array (FPGA) for 5-level single-phase Neutral Point Multilevel Inverter (NPC-MLI) is described. In the study, the analysis and simulation of the NPC-MLI topology was carried out in the MATLAB/Simulink environment. The control algorithm for the switching components in the NPC-MLI topology is created with XSG block sets in the MATLAB/Simulink environment. The SPWM technique, which is common in literature, was used as the control algorithm and the basic principles of the SPWM technique were mentioned in detail. In the experimental study, the control algorithm created in the MATLAB/Simulink environment was automatically converted to HDL code, run in VIVADO software and embedded in the FPGA environment. Both simulation and experimental measurements of the signals used to drive the switching components in the NPC-MLI topology are shown. In the simulation study, a load is connected to the output voltage of the NPC-MLI topology and analyzed both with filter and without filter. While the Total Harmonic Distortion (THD) value was 27.06% without filter, it was observed that the THD value was 1.24% with filter. As a result of the simulation and experimental studies, it has been seen that the SPWM method has been successfully implemented in the FPGA environment for the 5-level single-phase NPC-MLI topology. In conclusion, this study shows that the FPGA-based SPWM method can be used effectively for the generation of fast switching signals of multilevel inverters, which is an important application in the field of power electronics.