Hydro turbine speed control using robust cascade governor controllers

Abstract

SUMMARYThis paper presents a cascade control approach to the design of governors for speed control of hydro turbines in power generation units. The key issues include the problems of model uncertainty, inner and outer loop disturbances, load rejections and attenuation of measurement noise. Gate position deviation signal is used as a supplementary inner loop manipulated variable in the proposed cascade control. The effect of water hammer, travelling waves and inelastic water penstocks is included in the hydro turbine model. The polynomial H 1 design method is used to design cascade governor controllers. Dynamic weighting functions of the H 1 design method provide the required control actions. A cascade robust governor ensures that the overall system remains asymptotically stable for all permissible norm-bounded uncertainties and system oscillations. The results presented in the time and frequency domains are compared with conventional PID and PID cascade designs. The results show that the performance of the system is significantly improved by the proposed cascade governor design.

Simulation Study on Dynamics of Hydraulic Turbines Used in Drilling Engineering

“…e fluid power technology can achieve high power output with low system mass compared to other common powertrain technologies [9]. Hydraulic turbine [10][11][12] is the most common energy conversion device that converts hydraulic pressure into rotary motion, which is commonly used [2,[13][14][15][16][17][18][19][20][21][22][23][24] in wind energy, hydraulic turbines, hydraulic motors, etc. Ge et al [15] studied the Reynolds number of airfoil aerodynamic performances and its influence on the optimal design of wind turbine rotor and discussed the maximum power coefficient; Hansen [16] developed and tested an airfoil optimization method for wind turbine applications, which can control the performance loss caused by leading edge contamination.…”

Improved nonlinear turbine-governor model and parameter assessment for a large hydropower plant

“…The applicable scope of several Francis turbine models is analyzed, and different models have different simulation accuracies. [16][17][18][19][20][21] The simplified hydropower system model is suitable for small fluctuation, but of which the dynamic process may lead to unreasonable results under big hydropower disturbance or other issues. 16,17 The nonlinear turbine model should be used in the whole dynamic simulation process.…”