A Hydroelectric Plant Simulation Model to Test the Performance of Actual Governor Control Systems

A simulation model of the hydraulic system of a hydroelectric power plant is developed and implemented in a real time simulator. The main purpose of the simulator is to test the performance of actual governor control systems using hardware-in-the-loop techniques, in which the actual governor control system is connected to a real time simulator instead of being connected to real equipment. This paper focuses on the modeling of the hydraulic system to be implemented in the simulator. The model consists of an unrestricted reservoir, conduits to transport water, and a turbine to convert the potential energy of the fluid into mechanical power. A nonlinear mathematical model for a non-elastic water column is implemented. Effects due to a surge tank and to various turbines connected to a common tunnel are included in the model by considering head and flow variations at the junction of the common tunnel and the individual penstocks. The model is evaluated by comparing results from simulations with field tests from a four-unit hydroelectric power plant (55 MW per unit). Comparisons show that the model reproduces the general behavior of the field tests. However some deviations are observed during the transient response, in particular the simulation results appear to respond faster than field data.