A Variable Parameter Control Method for the Turbine Governor in a Tunnel with Variable Ceiling and High Tailwater

Abstract

The invention relates to a variable parameter control method for a hydro governor of a variable-crown elevation tailrace tunnel. According to field tests of different water heads and different downstream water levels, optimal PID control parameters of the hydro governor at different water head sections and different downstream water level sections are determined through simulating calculation, and finally a parameter list is obtained. A working head of a water turbine and signals of downstream water levels are introduced to the hydro governor, the hydro governor automatically selects the PID parameters in the parameter list according to the real-time working head of the water turbine and the real-time downstream water levels, and therefore a regulating system of the water turbine of the variable-crown elevation tailrace tunnel can meet the stability requirement and has high regulation quality.

Description

technical field [0001] The invention relates to the fields of automatic control of a hydropower station and hydraulics of a hydropower station, in particular to a variable parameter control method for a hydraulic turbine governor of a tailwater tunnel with variable ceiling height. Background technique [0002] The tailrace tunnel with variable roof height is a brand-new design concept proposed by my country in the design of hydropower by referring to the design ideas of the former Soviet Union. For large-scale hydropower stations with long water system and low water head, replacing the tailwater surge chamber based on the requirements of turbine regulation guarantee can not only greatly reduce the project investment, but also have the advantages of convenient construction and stable cavern structure. Currently, the Three Gorges, Xiangyang Some large-scale hydropower stations such as Jiaba, Pengshui, and Baise have adopted the structure of variable roof and high tailwater tunne...

AI Technical Summary

Problems solved by technology

[0004] Although the design of the tailrace tunnel with variable roof height can well meet the requirements of the large fluctuation transition process of the hydropower station and replace the tailwater surge chamber, due to the complex hydraulic fluctuations in the tailrace tunnel with variable roof height, there are water hammer elastic waves and the quality of the gate shaft. The superposition of gravity waves and gravity waves in the non-pressure section of the tailrace tunnel affects the stability and regulation quality of the turbine regulation system

At the same time, the hydraulic characteristics of the tailrace tunnel with variable roof height are closely related to the downstream water level. When the downstream water level is low, the pressurized full flow section is short and the unpressurized open flow section is long. During the adjustment process, the open channel flow fluctuates significantly, which may cause the adjustment system low-frequency oscillation; as the downstream water level rises, the pressurized flow section increases, although the average flow velocity also gradually decreases, but the inertial acceleration time of the water flow increases, and the maximum value can be reached when the entire length of the tailrace tunnel is under pressurized flow , the huge flow inertia will definitely affect the stability and adjustment quality of the entire adjustment system

At present, some hydropower units with variable roof and high tail water tunnels in China have experienced poor regulation quality, which makes it difficult for the primary frequency regulation and AGC load regulation rate to meet the requirements of the power grid, especially the dynamic response of the entire regulation system under different tail water levels. Significant difference in process

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