Abstract: With the large-scale connections of distributed generator（DG） into grid and the requirement of low voltage ride-through ability for DG, it is quite an important issue to analyze the influences of DG on a faulted grid. This paper focused on the fault model of a PQ-control mode inverter-based DG. Based on the instantaneous power theory and two basic constraints of DG output current, the generalized current reference expression of DG can be derived, it guarantee that DG’s average output power always keep track of power references. Adjusting parameters of that expression result in flexible control strategies, meanwhile. Moreover, this paper proposed the computational method of DG’s power references with the current limiting constriction. Finally, the DG fault response model and current limiting algorithm was verified to be correct by Simulink simulations.