With the continuous improvement of corresponding standards and the continuous maturity of power quality online monitoring technology, the power quality online monitoring system will play an important role in ensuring power quality, shortening power outage time, reducing equipment and production failure rate, reducing energy consumption and so on.

The detection of power quality is an important part of power quality problems, which can be used to determine the causes of equipment misoperation. Accurate information can provide useful clues for the solution. The on-line power quality monitoring device can quickly and systematically display these useful information.

Electric energy is a whole from production to consumption. The generation, transmission, distribution, transformation and utilization of power system are always in dynamic balance, and any link will have an impact on power quality. The formulation of power quality standard is to determine the allowable value of appropriate power quality index deviation. The power quality standard shall meet the following three points:

       1. Basically, it can ensure the safe, continuous power supply and economic operation of the power system;

       2. Generally, it can ensure the normal power supply of users' electrical equipment;

       3. The power sector (including interference users) should reach the standard after making certain efforts on the basis of the current technical level.