DYNAMIC SIMULATION OF STAND ALONE AND GRID CONNECTED SMALL HYDRO PLANTS

Abstract

In this study, dynamic simulation of stand alone and grid connected small hydro-electric plants (SHPs) has been attempted. Literature covering the simulation studies in small as • well as large hydro electric plants and mathematical modellig of plant components of small hydro electric plants have been reviewed. Mathematical models i.e. differencial equations, describing the dynamic behaviour of, various components of small hydro plants i.e. Wier, flume, surge tank, penstock, turbine governor, generator and grid are studied. Two models describing wier dynamics and referred as 'Bilinear' and linear respectively are discussed. Rigid water column theory is used for depicting water hammer in penstock. Three methods of modelling turbine charactristics are presented and two types of governors commonly used is small Ilydro plants are described. Using these differential equations, an integrated, per unit, state space model of .the dynamic system is developed. Computer programs to solve these differential equations for stand alone system using fifth order Runge-Kutta Method with adaptive step size control have been developed in FORTRAN-77. Procedure for simulating grid connected system is elaborated. Many simulation experiments to study the transients caused by different disturbances/events have also been carried out, using the above models and results compared with existing results/experimentation data.