A Strategy for Harmonic Reduction Using Complete Solution

Abstract --One of the major problems in electric power quality is the harmonic contents. There are several methods of indicating the quantity of harmonic contents. As per IEEE 519 std. these parameters of power quality measurement, are four in number, of which Total Harmonic Distortion is most widely used. In electrical systems, harmonics increase business operating costs by increasing downtime, placing undue burden on the electrical infrastructure, making power factor correction difficult and causing poor total power factor. Harmonics are a circumstance of progress, and they affect all the operating systems. Selective harmonic elimination-pulse width modulation techniques offer a tight control of the harmonic spectrum of a given voltage waveform generated by a power electronic converter along with a low number of switching transitions. Traditional optimization methods suffer from various drawbacks, such as prolonged and tedious computational steps and convergence to local optima, thus, the more the number of harmonics to be eliminated, the larger the computational complexity and time. Thus in this paper, we adopt an approach which is to choose the switching times (angles) such that a desired fundamental output is generated and specifically chosen harmonics of the fundamental are suppressed. This is referred to as harmonic elimination or programmed harmonic elimination as the switching angles are chosen (programmed) to eliminate specific harmonics.