A Graphical Approach in Selective Harmonic Elimination for Simultaneous Reduction of Multiple Harmonics and Overall THD

A simple and efficient graphical selective harmonic elimination method has been developed in this paper using which multiple harmonics can be simultaneously reduced even with two switchings per quarter. The method is also extended to reduce overall THD with the help of a cost function. The boundary conditions of the switching angles have been analytically derived, after which the switching angles are obtained graphically for simultaneous removal of lower-order harmonics. The proposed technique has been extensively simulated at various modulation indices using MATLAB/Simulink to validate the proposed graphical analysis.