Looking at the demand, there is a need to increase the capacity of generation in West Sumatra power system. There will be construction of many power plants in West Sumatra for supplying the electricity demand which continues to rise every year and increasing the reserve margin of the region and the West Sumatra power system. One of the power plants that will be constructed is Lubu Hydro Power Plant (HPP) that utilizes the potential of flow and head on the Lubu River. The Lubu HPP is located in Tanjungbetung Village, North Rao District, Pasaman Regency, West Sumatra Province. The connection of Lubu hydro power plant mentioned before, require in-depth technical study to see the effect of the connection of the hydro power plant to the performance of the electrical system, especially the electrical system in West Sumatra Grid. Furthermore, if it is found any problems that occur on the connection of the hydro power plant to the West Sumatra Grid, mitigation mechanism will be conducted and recommended to resolve the problem. However, the new power plant and transmission line will affect system performance. To illustrate the influence of power plant and its transmission line, grid study should be conducted.