Power quality problems in power systems can be divided into two categories: steady-state and transient. Steady-state power quality problems are mainly characterized by waveform distortion, which lasts for a long time, and can be divided into the following types: harmonics, interharmonics, voltage unbalance, overvoltage, and undervoltage. Transient power quality problems are usually characterized by short spectrum and duration, including pulse transients and oscillatory transients, which are manifested in the form of: voltage transients, voltage flicker, voltage swells, sags, and short-term power outages. Power quality monitoring is an important part of identifying power quality problems and can be used to determine the cause of power system failures.
    The new generation of power quality online monitoring system can continuously record the waveform of the power system for more than one year, and the power quality monitoring network can be built in the power system. Using unique data compression technology, all parameters of each power grid cycle are continuously recorded for more than one year, with a sampling rate of up to 1024 points/weekly wave, and the data of each cycle can be restored and displayed, without event triggering and no record being forgotten. It has a variety of use ranges for measuring 50Hz/60Hz power system and 400Hz power system to adapt to different complex working conditions, and can be used for time synchronization through GPS to form a regional power quality monitoring network. It can be independently configured to test, analyze and record at the user's site, which solves the bottleneck problem of large data transmission; It can also be sent to the management center via Ethernet, and with professional power quality analysis software, comprehensive power quality reporting and data analysis can be carried out.