Harmonic Minimization for Cascade Multilevel Inverter based on Genetic Algorithm

Multilevel inverter have been attracting increasing interest recently due to the increased power rating, improving harmonic performance, and reduced electromagnetic inference (EMI) emission. In this project, a genetic algorithm (GA) optimization technique is applied to 7-level cascaded multilevel inverter which determines optimum switching angles to eliminate 5 and 7th order harmonics. Genetic Algorithm is developed as the preferred solution algorithm of specific harmonic elimination (PWMSHE) switching pattern. This project describes an efficient genetic algorithm that reduces significantly the computational burden resulting in fast convergence. The output voltage contains harmonics the different type of harmonics elimination methods are available. But all the method having some limitations. This project deals with how to reduce the particular harmonics in the output voltage of inverter. The concept of the harmonic stepped waveform technique for the multilevel inverter to be presented. By applying this concept, selected harmonic can be eliminated, and the output voltage THD can be improved. A procedure to achieve the appropriate switching angle is to be proposed. The proposed project is to be simulated by using MATLAB. Keywords— Multi level inverter, Selective harmonic elimination, Genetic algorithm, Total harmonic distortion