The increasing complexity of today's power systems, and the growing numbers of power electronic devices that are being introduced, adds to the risk of power quality problems caused by harmonics. Non-linear loads into power systems, non-sinusoidal and distorted current waveforms, and voltage distortion have become common, and these phenomena can lead to power losses and damage to equipment. Understanding and Managing Power Quality Issues is a reference for researchers involved with power systems, professionals in power equipment industry and at grid operators, as well as for advanced students, transmission network and grid operators. The authors use detailed mathematical analysis to describe the mechanisms of various power quality issues. Harmonics in the power system are a major focus, and coverage also encompasses power quality power supply systems, reliability indices, sinusoidal and non-sinusoidal conditions, techniques for control of voltage variation, reactive power, active power quality management, and current trends.