Power Quality can be defined as the characteristics of the electricity at a given point on an electrical system, evaluated against a set of reference technical parameters. These parameters might relate to the compatibility between electricity supplied on a network and the loads connected to that network. The voltage waveform is normally distorted, and we have the so called Power Quality disturbances such as; voltage dips/swells, transients, harmonics and voltage unbalance amongst others. The study of Power Quality encompasses the Power Quality disturbances, as well as Power Quality standards, and Power Quality Monitoring. This project will tackle the subject of Power Quality, Power Quality Disturbances, Power Quality Standards as well as Power Quality Monitoring. A general description of each of the disturbances will be given, and the basic techniques which are used to mitigate that disturbance so as to improve the quality of the supply are presented. Author: Dr. Hidaia alassouli Email: hidaia_alassouli@hotmail.co