THD Effectiveness of Five-Level Inverters: CHB vs. NPC

In this study, two popular multilevel inverter topologies—the Neutral Point Clamped (NPC) and the Cascaded H-Bridge (CHB)—are compared. Identical variables are used to assess the two distinct kinds of inverters: 50Hz as the working frequency and 380V RMS for the voltage from the line. To ascertain the expected results of every kind of inverter, simulating analyses were carried out on THD, switching loss, and waveform integrity. The study's findings show that although both kinds of multilevel inverters are capable of producing multilevel voltage through synthesis, the CHB outperforms the NPC inverter with regard to of THD and harmonic distortion and may produce multilevel voltage to a wider variety of techniques for modulation (phase-to-phase shifting). Additionally, the NPC uses smaller components and has a simpler DC end connecting architecture, which may be advantageous in certain situations where expense and reliability are crucial. These findings can therefore help in the selection of an inverter topology to satisfy the demands of powerful (over 1MGA), medium voltage (3–15kV) scenarios that demand superior efficiency, THD, and intricate topological development concerns. For 5-level, three-phase structures, CHB is more effective at producing THD and harmonic efficiency than NPC, even though NPC has a simpler design and a much lower practical footprint.