A LCL filter is an effective device to suppress high level frequency components which are generated by PWM converter. However, the use of the LCL filter can cause the stability problems of the system. This paper presents two control methods of the LCL filter in an isolated battery-converterwind turbine system by considering positions of control currents, the converter side currents and the grid side currents. In addition, the effect of the unit power factor control of the system is also mentioned in this paper. The simulation results show out the effectiveness of control methods.