A novel strategy for Selective Harmonic Elimination based on a sine-sine PWM model

SHE (Selective Harmonic Elimination) method does not allow elimination of harmonics in real time. The switching angles are calculated offline using iterative computations and programmed into a digital processor. In this paper we propose a novel harmonic elimination technique where real time modulation is used to eliminate the undesired harmonics. The method uses sine-sine modulation as a base model. The switching angles determined through the model are perturbed to compute the angles necessary to eliminate the selected harmonics, thus reducing the complexity of computation. Using these switching angles, we are advancing a method of finding a modified carrier as a means to provide a low cost comparison-based solution to harmonic elimination. The reference sinusoid with the desired signal frequency is compared against the modified carrier that has same time period as the reference. Simulation/experimental studies verify the proposed method.