Influence of V/Hz Limiter on Generator in Isolated Operation

The action of V/Hz limiter of generator excitation system and its influence on generator in isolated operation are analyzed with the generator in Youjiang hydro power station as an example which is in isolated operation with local load after the trip of main transformer of 500kV Baise substation in Guangxi power grid. It is pointed out that the action of V/Hz limiter is the reason that causes the long time operation of generator under low voltage and low frequency status. Suggestions on the functions of V/Hz limiter and how to avoid such low voltage and low frequency operation status are proposed.