Optimal Utilization of Weakly Interconnected Small Scale Hydro Power System

Small hydropower is an attractive technology for rural electrification. In many isolated areas, this is the only source of power generation. Small hydropower systems (SHS) are also common in remote areas with weak interconnection to the main grid. This paper presents a simulation study of SHS connected to a distribution grid, which feeds two village loads. It is shown that for long distribution distances (>50 km), local voltage control made it possible to keep the steady-state voltage variations within acceptable limits. Furthermore, electrical energy storage is considered for reducing the use of the main grid for export and import of power. For a case with 30 GWh yearly load and 38 GWh hydro generation, the level of self-supply increased from 73% to 91% by installing a 5 MW / 50 MWh energy storage system. The simulation program was developed in Matlab, using the MATPOWER package for solving the power flow problem.