Abstract Fast control valve technology is one of the effective ways to improve the transit stability of electrical power grid.However

it is not always necessary for every unit or project.Some more careful and comprehensive study and test are required.Before applying this technology

Yuanbaoshan power plant did a lot of work in research and testing.Five different tests were conducted according to theoretical studies.They are the fast load reducing at 290 MW

natural frequency measurement of torsional vibration of shaft system

preliminary test of fast valve closing valve at 180 MW

and fast valve closing tests （two） of complete control valve at 180 MW

and fast valve closing tests （two） of complete control valve at 290 MW（separate residence times 0.8 s and 1.2 s）.