Power quality monitoring device is a kind of industry measurement tool for recording and analyzing power quality problems in power grid. It can capture common power quality problems such as harmonics, voltage fluctuation, flicker, power and three-phase imbalance at fault site. It can provide performance evaluation and governance decision-makers of power quality for smart grid, new energy, electrified railway and large-scale industrial power Case.

The power quality online monitoring device is fixed on the site. It is connected to the remote PC terminal through the communication interface to view the current real-time monitoring data. The occurrence of many accidents is symptomatic, and the events occur gradually from small to large. The data fed back by the online power quality monitoring device can take preventive measures in advance.

Power quality analyzer is a portable device, which is suitable for testing power quality in a short time, and then gives a test report to provide the basis for the follow-up treatment scheme.

The function of power quality on-line monitoring device and power quality analyzer is roughly the same, but the power quality analyzer is portable, small in size, and can follow the measurement. The power quality online monitoring device is a long-term equipment installed on the operation site and transmits data in real time, so it is called "online type".