Grid connection test is the work that must be done before the grid connection generation of new power plant and is of great significance for safe and stable operation of power system. In this paper

the fault during pulse closing test of generator unit on the line is analyzed in detail during the grid connection test period of certain hydra power plant.The fault is simulated and reproduced by DIgSILENT/PowerFactory software

and the solution strategy and optimal allocation scheme of the fault is proposed. The theoretical analysis for different installation position of shunt reactor and different effect of compensation to the systemis made

the corresponding optimal solution is proposed and the effectiveness and feasibility of the strategy is verified. Both the study contents and result have definite instruction significance for the theoretical analysis and engineering application.