Power quality directly affects the stability and reliability of the whole system. In order to ensure the safe, reliable and economic operation of the power system and the legitimate rights and interests of power users, real-time monitoring and analysis of power quality need to be carried out. It is necessary to install online power quality monitoring devices. According to the monitoring results, the rectification scheme is proposed to strengthen preventive measures and limit interference sources.

Power quality problems can be divided into steady state and transient state. Steady state power quality problems are caused by continuous power disturbances (mainly load power changes), which last for a long time, and the voltage and current change slowly during the period. Transient power quality problems are caused by sudden power disturbances (such as faults, large load switching, etc.), which generally last for a short time, but during the period, the voltage or current seriously deviates from its rated value or rational waveform, and the change rate is large.

Power quality on-line monitoring can complete the functions of real-time data acquisition, storage, remote transmission, synthesis and statistics of power supply lines, and then analyze and track power quality accurately and in real time. It has novel technical conception, compact structure, low cost, reliable operation, and can complete high-speed and stable power quality on-line monitoring, meeting the requirements of the rapid development of the power industry.