The positive-sequence control strategy is adopted for the integration of large-scale use of inverter-interfaced generators(IIGs)under fault conditions

and the fault current supplied by IIGs only consists of positive-sequence components. Such being the case

the positive-and negative-sequence current distribution coefficients on the IIG side are no longer equal any more. Based on this fault characteristic

the performance of the two traditional phase selectors for transmission lines emanating from IIGs

e. g.

the phase selector of the sudden-change of two-phase current difference and the phase selector of the phase comparison of symmetrical components

are analyzed. The phase selectors on the IIG side fail to operate

whereas those on the system side can still make correct decisions. Simulation results based on PSCAD validate the effectiveness of the analysis. Finally

prospective phase selector criterion for systems containing IIGs is proposed. This work is supported by China Ministry of Education of Science and Technology Research Projects(No. 113023A)and State Grid Corporation of China(No. SGTJDK00DWJS1500098).