Electromagnetic compatibility in the industrial electric power supply systems

Over the past years, the problem of electromagnetic compatibility is becoming more and more prevalent among electric utilities´ managers and engineering stuff. The main cause is the growing applications of nonlinear, unbalanced and intermittent loads in residential and industrial sectors. The definitions for electromagnetic disturbances, sources of distortions including rectifiers, frequency converters, arc furnaces, welding installations and wind turbines as well as their impact on electrical equipment, protective relaying and automatics are reviewed. Comprehensive analysis of the levels of harmonics, interharmonics, voltage unbalance and flicker in the industrial electric power supply systems is presented. Generalized approach to estimating the levels of electromagnetic disturbances is proposed. Most important passive and active solutions for cleaning up the distortions are discussed.