A New Carrier Based PWM for a 3-Phase 5-Level Neutral Point Clamped Inverter

This study presents a new pulse width modulation approach using a valley inserted triangular carrier waveform. This carrier wave is consisted of two equal halves and each half is further divided into five intervals with same temporal length. The performance comparison of conventional carrier waves namely trapezoidal triangular and triangular carrier wave with the new carrier wave employing three different modulation signal is drawn in terms of total harmonics distortion (THD) of output voltage, total power losses, efficiency, and junction temperature of the device for a 3-phase 5-level Neutral Point Clamped (NPC) inverter fed R-L load. All the three carrier waves are implemented utilizing the three fundamental Level Shifted (LS) Multicarrier PWM methods namely alternative phase opposition disposition (APOD), phase opposition disposition (POD), and phase disposition (PD). Simulation results prove that the proposed carrier performs better THD performance on the expense of efficiency (which got reduced by 0.25% at the worst case) as compared to the triangular and trapezoidal carrier waveforms. The simulation is carried out for a 3-phase 5-level NPC inverter-fed R-L load using PLEXIM Simulation platform.