Electricity quality refers to the quality of electricity in the power system. The ideal electrical energy should be a perfectly symmetrical sine wave. Some factors can cause the waveform to deviate from the symmetrical sine, resulting in power quality issues. On the one hand, we study the influencing factors that can lead to power quality problems. On the other hand, we study the aspects of problems that these factors can cause. Finally, we need to study how to eliminate these factors to maximize the proximity of power to sine waves Strictly speaking, the main indicators for measuring power quality include voltage, frequency, and waveform. Generally speaking, it refers to high-quality power supply, including voltage quality, current quality, power supply quality, and electricity consumption quality. Power quality issues can be defined as voltage, current, or frequency deviations that cause electrical equipment malfunction or malfunction, including frequency deviations, voltage deviations, voltage fluctuations and flickers, three-phase imbalance, instantaneous or transient overvoltage, waveform distortion (harmonics), voltage dips, interruptions, surges, and power supply continuity An ideal power system should supply power to users at a constant frequency (50Hz) and sinusoidal waveform, at a specified voltage level (nominal voltage). In a three-phase AC power system, the voltage and current of each phase should be of equal amplitude, with a phase difference of 120. The symmetric state of. Due to the fact that the parameters of various components of the system (generators, transformers, lines, etc.) are not ideal linear or symmetrical, and the nature of the load varies and randomly changes. In addition, due to the imperfect control methods, as well as operational operations, external disturbances, and various faults, this ideal state does not exist in reality, resulting in various problems in grid operation, electrical equipment, and electricity consumption, This gave rise to the concept of Power Quality