To solve the problem of power quality, it is necessary to monitor the power quality parameters. Power quality monitoring can be divided into two ways: non online monitoring and online monitoring. The non online monitoring uses portable tester to test some points of concern from time to time. This method has small investment and is flexible, but there are obvious limitations, such as poor real-time, few monitoring indicators, lack of basis for decision-making and judgment, large workload and low efficiency.

The power quality online monitoring device integrates the functions of measurement and communication, and can effectively monitor the power quality. It is of great significance to ensure the safety, economy and reliability of power system operation.

The power quality monitoring device uses arm + DSP processor as the core, and the data acquisition department uses 10 channels. The sampling accuracy is high, and the actual measurement accuracy is up to the requirements of the national standard for power quality monitoring indicators. The large capacity storage space can meet the requirements for data storage of the power quality monitoring device, and can save the historical data for more than one year without losing power.

In terms of on-line monitoring function of power quality, in addition to the conventional monitoring of steady-state indexes of power quality, the device also monitors and records the transient disturbances of power quality, mainly the sudden rise and fall of voltage, which has strong practicability.