Comparison of Total Harmonic Distortion (THD) in Three-Level, Three-Phase Inverters Using Cascaded H-Bridge (CHB) and Neutral-Point-Clamped (NPC) Topologies

Utilizing the same parameters for operation, 50 Hz frequency, and 380 V line voltage, every single inverter is represented mathematically on the MATLAB/Simulink environment. The shape of the generated voltage's harmonics is examined using Fast Fourier Transform (FFT) approaches. The results demonstrate the benefits and drawbacks of each design by taking into account the THD values for each examined inverter with the exact same applied frequency and supply voltage. This paper uses modelling to analyse three-phase, three-level (CHB) and (NPC) inverters. Total harmonic distortion (THD), pattern efficacy, and structural complexity are all examined. Simulation findings show that the NPC architecture needs fewer DC sources and is simpler to control, whereas the CHB inverter generates less THD (~4.7%) compared with the NPC architecture (~9.2%). Because they provide better waveforms, less acoustic noise, and less switching strain, inverters that have less harmonic distortion are favoured in medium- and high-power applications