Harmonic Mitigation for Power Quality Improvement

Abstract

Now a days in every industry there exists non-linear load such as single-phase diode Bridge rectifiers, converters, inverters, low voltage power supplies, SMPS, arc furnace, personal computers, gas discharge lamps etc. In most of the 3-phase system the lowest and significant order of harmonic typically is 5th harmonic after the fundamental. It exists in the supply for application ranging from paper industry, steel industry, textile industry, welding industry. This harmonic incurs losses in the form of from increased heat dissipation in the windings and skin effect; where both are a function of the square of the RMS current. Harmonics also contribute to eddy currents and core losses. This extra heat can have a significant impact in reducing the operating life of any electrical instrument especially transformer insulation. The operating life of all other components existing in the system viz. cables, conductors and machines is affected by the exaggerated amount of current owing through them. Proposed project aims to implement and design of unity power factor controller for various industrial applications to provide system best power quality, protecting the system and components during transients, mitigating voltage sag/swell and controlling system inrush.