The characteristic analysis of voltage sag monitoring data is one of the key means to understand the voltage sag level in the region

which can provide the basic information for control and prevention of voltage sag. Based on the voltage sag monitoring data of power quality monitoring platform of Hainan power grid

the voltage sag waveform amplitude and duration

phase angle jump and sag type are calculated and analyzed. The results show that：the amplitude of 70% measured voltage sag is higher than 0.7 pu

and the duration is less than 0.1 s. 90% of the measured voltage sags are in the range of ［-10°

10°］

which can be inferred that most of the sensitive equipment in this area can avoid the sags causing equipment failure due to the phase angle jump. 60% of the measured voltage sags are type D caused by singlephase ground fault

and only 3.79% are symmetrical sags type A. The analysis data and results can provide a technical basis for the decisionmaking of voltage sag control in grid side and user side

and for the setting and commissioning of relevant parameters by equipment manufacturers.