The zero voltage ride through(ZVRT)capability of an operating 2 MW doubly fed induction generator(DFIG)based wind turbines is validated in accordance with Australian national electricity rules. First of all

a theoretical analysis is made of the rotor current(voltage)during diverse voltage sag faults. Then some possible improvements are discussed in order to optimize control strategies and physical devices. In addition

the design of the Crowbar is adjusted including its reselecting resistance and overcurrent capability via pretest and simulation. Finally

the feasibility of innovation is shown with the test results of zero voltage sag faults taken into account. The proposed scheme can provide theoretical guidance for practical DFIG-based wind turbines with optimal operation and technical innovation as well as optimal control design to improve its grid connection capability.This work is supported by National High Technology Research and Development Program of China(863 Program)(No. 2012AA051303).