Controlled interruption of fault currents can increase interrupting capacity and electrical lift of a high voltage circuit breaker.One of the most important issues for controlled interruption of fault current is to rapidly extract fault current parameters in order to predict the zero crossing of the fault currents as targets for synchronizing the opening command to the circuit breaker so as to achieve a pre-determined optimum arcing time.A quickly detecting approach based on weighed least mean squares（WLMS） for the fault current parameters is presented.And the F0 hypothesis test is used to detect the initial phase angle of the fault current

and the data sampling window size is changed adaptively.Numerical simulation tests of the proposed method are conducted using both artificial network data from the simulation of MATLAB and actual disturbance recording data.The results show that the proposed method can predict zeros of the fault current within half cycle after fault initiation

and its prediction errors are less than ±1 ms.