This paper presents disturbance rejection control algorithm at stationary reference frame for a grid connected inverter to reduce peak current during transient when grid fault occurs. The proposed control algorithm includes feedforward control, an observer for grid voltage disturbance estimation. Current vectors at stationary reference frame are controlled instead of current vectors at a synchronous reference frame. By doing this, phase estimation algorithm for grid voltage such as PLL can be avoided. and an entire control system can be simplified. However, phase delay and steady-state error are occurred. The drawbacks can be also compensated by applying the proposed algorithm.