A Review on the Generalized Formulations for Selective Harmonic Elimination (SHE-PWM) strategy

Better harmonics spectrum due to efficient elimination of dominant harmonics, Selective Harmonic Elimination (SHE-PWM) method has been extensively preferred for optimal control of multilevel inverters (MLI's). However, switching angle solution depends on the proper SHE problem formulation and solving techniques adopted. Various aspects which determines the formulation complexity such as nature of the waveform, number of step switching's, symmetry and voltage level characteristics has been discussed in this paper. Simulation results for multiple solution trajectories pertaining to single as well as multiple step switching transitions are evaluated using hybrid optimization method and presented for readers to attain better understanding of the SHE formulations and its related solutions.