Power quality is simply the interaction of electrical power with electrical equipment. If electrical equipment operates correctly and reliably without being damaged or stressed, we would say that the electrical power is of good quality. On the other hand, if the electrical equipment malfunctions, is unreliable, or is damaged during normal usage, we would suspect that the power quality is poor. As a general statement, any deviation from normal of a voltage source (either DC or AC) can be classified as a power quality issue. Power quality issues can be very high-speed events such as voltage impulses / transients, high frequency noise, wave shape faults, voltage swells and sags and total power loss. Each type of electrical equipment will be affected differently by power quality issues. By analyzing the electrical power and evaluating the equipment or load, we can determine if a power quality problem exists. Rolling brownouts, voltage sags, spikes, electrical noise and harmonic distortion are some common quality problems. Power Quality Monitoring, Analysis and Enhancement cover various aspects of power quality monitoring, analysis and power quality enhancement in transmission and distribution systems. The monitoring of electric power helps to identify the important power quality problems such as voltage sags and swells, interruptions, harmonics, and highfrequency noise, consistently seen in industrial and commercial grid applications. Troubleshooting these problems requires accurate measurements and analysis of power quality with monitoring instruments that can effectively locate issues and identify solutions. This book will be of great benefit to professionals, engineers and researchers.