Quality of Power: A Challenge to Power Engineers

Abstract

The proliferation of power electronics based equipment in the power system has had a profound impact on the quality of power supply world over High power industrial loads, such as adjustable speed drives, uninterruptible power supply (UPS), thyristor converters etc. and low power domestic loads such as television sets, fax machines, computers, electronic ballast etc. draw strongly distorted currents resulting in non-sinusoidal supply voltages across the power system network. Furthermore, conventional loads such as large arc-furnaces and single phase welding machines also contribute significantly to the fluctuation, unbalance and flicker in supply voltages. It is expected that the use of equipment based on power electronics technology would further increase in the future. - .• Although, the use of such a large variety of power electronic equipment have been beneficial to industries in terms of energy saving, reduced maintenance, low running costs and increased production but their adverse effect on the power system and its components has become a serious concern for utilities and industries. "Quality of power" is necessary to accelerate overall development. The entire power chain starting from generating system, transmission and distribution system and consumers are immensely benefited by maintaining high standards of quality of power In this respect, "Power" should be treated like any other commodity. An attempt has been made in this paper to define what we really mean by "Quality of power" its impacts, parameters influencing the quality of power and suggestions to achieve higher levels of standards in this area.