This paper introduces an intelligent power quality monitoring and analysis system for Hunan grid

which includes monitoring management module

assessment module

forecast and warning module. In this system

management

monitoring and intelligent analysis of interference sources are realized to prevent power quality accidents

which can provide important support to ensure the safe and economic operation of power grid. In the monitoring management module

the statistics of interference sources and real-time display of measured data are implemented. In the assessment module

not only evaluations of voltage deviation

harmonic

three-phase imbalance

frequency deviation

voltage fluctuation and flicker are implemented

but also power quality comprehensive evaluation based on the short board effect is established which can reflect the power quality level of a district power grid. The special power quality analysis of electrified railway

the HVDC converter station

the new energy power generation

and nonlinear loads. In the forecast and warning module

the power quality prediction can be implemented based on a large amount of historical monitoring data

using some intelligent algorithms such as the grey prediction

linear regression prediction and stochastic time series prediction

and the warning will be given when the power quality do not meet the requirement to avoid the potential risk.