PSO based Harmonic Reduction Technique for Wind Generated Power System

Converters are used in the utility interface of renewable energy system to reduce harmonic contents in line current/voltage and to increase reliability. These converters suffer from high level of Total Harmonic Distortion (THD) in the utility line currents/voltages which creates a lot of problems in the power system. In this paper selective harmonics are eliminated to reduce the THD, that is, the problem is to determine optimal switching angles for eliminate harmonics while maintaining the required fundamental currents/ voltages. The THD reduction is achieved by the help of multilevel inverter with equal separate dc sources using particle swarm optimization technique. This technique can be applied to multilevel inverters with any number of levels; as an example in this paper, an 11-level inverter is considered. Theoretical results are verified by experiments and simulations for an 11level H-bridge inverter. Results show that the proposed method does effectively eliminate a great number of specific harmonics, and the output voltage is resulted in low total harmonic distortion.