Nonlinear stability and dynamic characteristics of grid-connected hydropower station with surge tank of a long lateral pipe

2022 ◽  
Vol 136 ◽  
pp. 107654
Author(s):  
Tianyu Zhang ◽  
Jianzhong Zhou ◽  
Xinjie Lai ◽  
Yan Huang ◽  
Mengyao Li
Keyword(s):  
Nonlinear Stability ◽  
Dynamic Characteristics ◽  
Hydropower Station ◽  
Surge Tank

Mechanism of air-trapped vertical vortices in long-corridor-shaped surge tank of hydropower station and their elimination

2017 ◽  
Vol 29 (5) ◽  
pp. 845-853 ◽  
Author(s):  
Fang Cai ◽  
Yong-guang Cheng ◽  
Lin-sheng Xia ◽  
Yong-qi Jiang
Keyword(s):  
Hydropower Station ◽  
Surge Tank

Switched Model and Dynamic Analysis of a Hydroturbine Governing System in the Process of Load Rejection Transient

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Huanhuan Li ◽  
Diyi Chen ◽  
Feifei Wang ◽  
Hao Zhang
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Numerical Simulations ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Hydropower Station ◽  
Transfer Coefficients ◽  
Operational Conditions ◽  
Governing System ◽  
Hammer Impact

In this paper, we pay attention to studying the switched model of the hydroturbine governing system (HTGS) by introducing the concept of the switching of operational conditions. More specifically, utilizing the data of an existent hydropower station in China, we propose six nonlinear dynamic transfer coefficients of the hydroturbine, which can better describe the dynamic characteristics of the HTGS in the process of load rejection transient. Moreover, the elastic water hammer-impact of the penstock system and the nonlinearity of the generator for the process of load rejection transient are considered. Based on the combination of the different regulation modes of the governor and the corresponding running conditions of the hydroelectric generating unit, a novel nonlinear dynamic switched mathematical model of the HTGS is finally established. Meanwhile, the nonlinear dynamic behaviors of the governing system are exhaustively investigated using numerical simulations. These methods and analytical results will provide some theory bases for running a hydropower station.

scholarly journals Study on Selection of Pressure Regulating Valve for Hydropower Station with Both Surge Tank and Pressure Regulating Valve

2018 ◽  
Vol 246 ◽  
pp. 01033
Author(s):  
Tianchi Zhou ◽  
Gaohui Li ◽  
Yimin Chen
Keyword(s):  
Transient Process ◽  
Maximum Flow ◽  
Hydropower Station ◽  
Surge Tank ◽  
Calculation Results ◽  
Practical Engineering ◽  
Spiral Case ◽  
Unit Speed ◽  
Working Principle ◽  
Selection Of

The transient process in the hydropower station with both surge tank and pressure regulating valve is quite complicated and also critical to operation safety. According to the pressure regulating valve working principle, the influence of the valve diameter on the unit speed and spiral case pressure was analyzed theoretically. Mathematical models of the surge tank and pressure regulating valve in the hydropower station were established based on the characteristic method. In a practical engineering, numerical simulation of large fluctuation and hydraulic disturbance transient process are conducted, verifying the correctness of the theoretical analysis. Based on the calculation results, three principles for selecting the valve diameter are concluded: first, making sure the unit speed meet the regulating guarantee requirements when guide vanes fast close; second, the maximum spiral case pressure of two times should be approximate to each other by controlling the superposition of surge wave and water hammer; third, the maximum flow of the valve should be as close to the rated flow of the turbine as possible. The principles are helpful for selecting the valve diameter in similar hydropower station.

scholarly journals Hydraulic Transients in the Long Diversion-Type Hydropower Station with a Complex Differential Surge Tank

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaodong Yu ◽  
Jian Zhang ◽  
Ling Zhou
Keyword(s):  
Pressure Difference ◽  
Mathematic Model ◽  
Hydropower Station ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Hydraulic Transients ◽  
Rotating Speed ◽  
Spiral Case ◽  
Two Sides ◽  
Breast Wall

Based on the theory of hydraulic transients and the method of characteristics (MOC), a mathematic model of the differential surge tank with pressure-reduction orifices (PROs) and overflow weirs for transient calculation is proposed. The numerical model of hydraulic transients is established using the data of a practical hydropower station; and the probable transients are simulated. The results show that successive load rejection is critical for calculating the maximum pressure in spiral case and the maximum rotating speed of runner when the bifurcated pipe is converging under the surge tank in a diversion-type hydropower station; the pressure difference between two sides of breast wall is large during transient conditions, and it would be more serious when simultaneous load rejections happen after load acceptance; the reasonable arrangement of PROs on breast wall can effectively decrease the pressure difference.

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