Effect of throttling orifice head loss on dynamic behavior of hydro-turbine governing system with air cushion surge chamber

29th IAHR Symposium on Hydraulic Machinery and Systems

Guo, W.C.^1^2 ; Yang, J.^2^3 ; Yang, J.B.^4

School of Hydropower and Information Engineering, Huazhong University of Science and Technology, Wuhan

430074, China^1

Division of Hydraulic Engineering, Royal Institute of Technology, Stockholm

SE-100 44, Sweden^2

RandD Laboratories, Vattenfall AB, Alvkarleby

SE-814 26, Sweden^3

State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan

430072, China^4

关键词: Bifurcation points;    Dynamic behaviors;    Hopf bifurcation theory;    Hydro turbine governing systems;    Nonlinear dynamic behaviors;    Nonlinear mathematical model;    Nonlinear state equations;    Numerical integrations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/5/052018/pdf
DOI  :  10.1088/1755-1315/240/5/052018

来源: IOP

【 摘 要 】

This paper aims to study the effect of throttling orifice head loss on the dynamic behavior of the hydro-turbine governing system with air cushion surge chamber. Firstly, a nonlinear mathematical model of hydro-turbine governing system considering the nonlinear head loss of throttling orifice is established. Then, the nonlinear dynamic behavior of the hydro-turbine governing system is investigated by using the Hopf bifurcation theory and direct numerical integration. The stability and dynamic response of the system are detailed described. Finally, the effect mechanism of throttling orifice head loss on the dynamic behavior of system is revealed based on the comparison between the cases with nonlinear head loss and no head loss. The results indicate that the mathematical model considering the nonlinear head loss of throttling orifice for the hydro-turbine governing system is a fifth-order nonlinear state equation. The system goes through Hopf bifurcation at the bifurcation points and the type of Hopf bifurcation is supercritical. The domain at the bottom of the bifurcation line is the stable domain. The throttling orifice cannot affect the system stability through its head loss. The throttling orifice can affect the system dynamic response through its head loss. The throttling orifice head loss is favorable for the damping of the water level oscillation in the surge chamber.