Power quality refers to the quality of the AC power supplied to the user through the public power grid. Generally speaking, it refers to the quality of the power in the power grid lines. Power quality problems are mainly caused by the terminal load side. For example, the impact reactive load will cause the grid voltage to generate Violent fluctuations reduce the quality of power supply. When the power quality of the power grid is disturbed or polluted and cannot meet the relevant national standards, it is necessary to improve the power quality of the power grid in a targeted manner. To understand the actual situation of the power quality of the power grid, it is necessary to have the corresponding equipment power quality analyzer ( Also known as three-phase power quality analyzer) to test and analyze it.