Modified extremum seeking controller for hydraulic turbine speed control

Abstract

In the past, researchers have done various attempts to improve hydraulic turbine precise speed control and use synchronization time between turbine/generator to grid as a test bench. These attempts were either based on improving the instant when phase difference between two systems becomes zero or to control speed precisely using mathematical model-based techniques. Due to highly nonlinear nature of the hydro turbines, the models presented in the past were never perfect. In this research work, a model free approach is adopted to improve the precise speed control of hydraulic turbines. The developed model free system outperformed old model-based techniques in both stable as well as unstable grids. As per results obtained, grid instability had negligible effect on the speed control and synchronization time. The developed system is able control the hydro turbine speed during synchronization up to a 5 mHz level.