Optimal switching angles calculation in multilevel inverter using convolution operator and Harmony Search algorithm

Several methods have been used to eliminate or minimize voltage harmonics of multi-level inverters output. This paper introduce a new method to improve multi-level inverters output. The aim of optimization is to produce an output stepped waveform as close to the desired fundamental component as possible, i.e. a waveform with the fundamental component of the desired value and possible minimum THD. Convolution operator and time domain criterion is used to obtain better solution. Since Harmony Search algorithm has shown some advantages over the other common algorithms, it is chosen as the optimization tool in this study. The proposed method is applied to a seven level inverter and simulation results are compared with those of previous similar works.