In view of requirement of fast information coordination among the distribution power supply

load and equipment in the active distribution network

a kind of method based on generalized fast S-transform（GFST）is proposed for disturbance parameter detection of power quality of the active distribution network.Firstly

Fourier transform power spectrum of the disturbance signal is treated by the use of threshold filter and dynamic measurement method

the main frequency point is found out and GFST is performed so to reduce the redundant calculation and speed up processing speed of signal. Secondly

the Kurtosis index is introduced to determine the optimal window width adjustment factor of GFST. Finally

the disturbance features are extracted from the results of GFST with combination of physical meaning of disturbance signal for parameters detection of power quality disturbances. It is proved by the simulation comparison experiment that the new method is superior to the generalized S-transform in the aspects of error detection and calculation time and can meet accuracy and rapidity requirement.