Selective harmonic elimination PWM using ant colony optimization

Selective harmonic elimination pulse width modulation (SHEPWM) is a useful switching technique in multilevel inverters because of low number of switching and at the same time, high quality of output voltage waveform. The main problem in SHEPWM is finding the optimum switching angles with the aim of minimizing specific harmonics. Population-based optimization algorithms have been demonstrated to be an effective tool for such problems with transcendental equations and inequality constraints. In this paper, the ant colony optimization for continuous domains (ACO_ℝ) is applied to harmonic elimination problem in a seven-level cascaded inverter. Simulation results in MATLAB environment are compared with particle swarm optimization (PSO) algorithm, results show higher convergence rate of ACO_ℝ in comparison with PSO.