Review on Harmonics and its Eliminating Strategies in Power System

Non-linear loads are the major source of harmonics in the power system. These loads impose varying reactive-power demands that have to be compensated in order to improve the power factor and efficiently deliver the active power to the loads. This results in harmonic distortion-related problems, reducing the quality of electrical power and the performance of the power system. In this paper, the nature of harmonics that exists in the operation of various equipment, devices and components, the effects of harmonics and methods to eliminate the harmonics of power systems have been discussed briefly. The paper also reviews the pros and cons of various harmonics eliminating strategies followed in the literature and propose a new hybrid optimization method to eliminate the harmonics in multilevel inverters. The proposed hybrid optimization based harmonic elimination method calculates the switching angles for the multilevel inverter in real-time and offers a optimum switching angle at a faster convergence rate compared to other existing methods which calculate the switching angles off-line and look up tables were used, which leads to finding the near optimum switching angle and converges at a lower rate.