Modeling and Simulation of Basochhu Hydropower Plant: Islanding Operation Using Real-Time Performance Data

Abstract

This paper presents the dynamic modeling and simulation of the 64 MW Basochhu Hydro investigation of its island mode operation and network restoration. A robust real-time simulation model is necessary to analyze the static and dynamic control and operating characteristics of hydropower plant, which can be empirically modeled based on real-time performance measurements. The schematic layout of the BHP from the reservoir (pond) to the turbine is divided into sub-components, each of which is represented by mathematical differential-integral equations. The composite model was then validated by comparing the simulated and real-time measured responses. The paper also examined the preliminary test results of island mode operation and restoration to grid connection. The midnight load of Thimphu was arranged for island operation taking into account of the minimal power disruption. At the instant of grid disconnection, the active power of the test unit fell freely from 13 MW to 9 MW, activating the deflector control instantly cutting off the water jets proportional to the power drop. The measurements and simulation results confirmed that the Basochhu Hydropower Plant has robust governor control systems, and it can withstand the island mode operation, and reliably feed the local load without the need for grid interconnection.