Author(s)
Wadah Aljaism
- Manuscript ID: 140788
- Volume: 2
- Issue: 6
- Pages: 3376–3390
Subject Area: Engineering
Abstract
In this paper, two multilevel inverter topologies are presented and analysed: one is a 13-level Cascaded H-Bridge topology operating at 380 V RMS and 50 Hz, and the other one is a 13-level NPC topology operating at 380 V RMS and 50 Hz. A comprehensive analysis of these inverters using simulations will be performed in order to have a fair and comparable analysis between the two topologies. Both inverters are implemented in Simulink/Matlab and analyzed under the same conditions. The analysis of these inverters will include aspects such as DC link balancing, switching and conduction losses, Total Harmonic Distortion, quality of the waveform of the line-to-line voltage, and complexity of implementation. Because Nearest Level Modulation (NLM) has minimal switching losses and is suitable for high-level multilevel inverters, it is used. According to the simulation results, both topologies' harmonic performance is greatly improved by raising the voltage level from 11 to 13 levels. However, as compared to the NPC inverter, the CHB inverter continuously shows reduced THD, enhanced voltage symmetry, and less vulnerability to DC-link imbalance. The NPC architecture benefits from a unified DC-link structure; however, as the number of levels rises, it faces increased conduction losses and imbalances in neutral-point voltage. The results indicate that the 13-level NPC inverter is still desirable for small systems that need precise control of capacitor voltage, while the 13-level CHB inverter is better suitable for applications that require high voltage quality and modular scalability. The simulation results verify that:
• CHB delivers reduced losses, improved waveform symmetry, and lower THD.
• Although NPC offers a compact construction, high conduction losses and voltage imbalance make it difficult.
• Increasing voltage levels above 11 highlights CHB's structural advantages even more.
Applications requiring improved power quality and modular scalability are advised to use the 13-level CHB inverter.