THD Minimization under Low Switching Frequency for Superior Two Level Three Phase Inverter Performance

Abstract

The total number of switching pulses permitted in one-quarter of the fundamental-cycle of an inverter is restricted due to the restrictions of switching losses in high-power inverter devices. The elimination of major low-order dominating harmonics using SHEPWM (Selective Harmonic Elimination) is suggested in this research paper. The positive or negative voltage transition at the instant where fundamental voltage has the greatest positive slope distinguishes the various types of waveforms. Due to the switching loss limitations, two forms of the pole voltage PWM waveforms i.e., type A, type B, were studied in this research at lower pulse number (P = 5). For a two-level three-phase inverter, an ideal Pulse Width Modulated (PWM) waveform is developed for whole modulation index range in terms of least total harmonic distortion (THD). MATLAB simulation and practical experiments are performed for a two-level inverter to support the theoretical analysis and results.