CN-122014479-A - Vibration control method and system for variable-speed water pump turbine unit

CN122014479ACN 122014479 ACN122014479 ACN 122014479ACN-122014479-A

Abstract

The application provides a vibration control method and a system of a variable-speed water pump turbine unit, wherein the method comprises the following steps: and establishing a fluid-solid coupling model of the water pump turbine unit, and calculating to obtain the modal parameters of the fluid-solid coupling model of the water pump turbine unit in a water body environment by adopting an acoustic-solid coupling modal analysis method, wherein the modal parameters comprise the natural frequency of a set order. According to the current running speed or the expected running speed of the water pump turbine unit, calculating to obtain the hydraulic excitation frequency of the water pump turbine unit, and determining the natural frequency closest to the hydraulic excitation frequency from the modal parameters as the modal frequency. Comparing the modal frequency with the hydraulic excitation frequency when Determining a new operating speed and controlling the water pump-turbine set to operate at the new operating speed so that the water pump-turbine set operates at the new operating speed Wherein f e is the hydraulic excitation frequency, f n is the modal frequency, and δ is the safety margin threshold.

Inventors

LIU TAO
YE FEI
CHEN HONGYU
YANG XIAOLONG
ZHOU ZAN
ZHAO LEI
GAO YANMING
WANG ZHENGWEI

Assignees

南方电网调峰调频发电有限公司工程建设管理分公司
广州启安众智建设管理有限责任公司
清华大学

Dates

Publication Date: 20260512
Application Date: 20260324

Claims (13)

1. A vibration control method of a variable speed water pump turbine unit, comprising: Establishing a fluid-solid coupling model of the water pump turbine unit, and calculating to obtain the modal parameters of the fluid-solid coupling model of the water pump turbine unit in a water body environment by adopting an acoustic-solid coupling modal analysis method, wherein the fluid-solid coupling model comprises a fluid model and a structural solid model of the water pump turbine unit in the water body environment, and the modal parameters comprise natural frequencies with set orders; According to the current running speed or the running speed expected to be carried out of the water pump turbine unit, calculating to obtain the hydraulic excitation frequency of the water pump turbine unit, and determining the natural frequency closest to the hydraulic excitation frequency from the modal parameters as the modal frequency; comparing the modal frequency with the hydraulic excitation frequency when Determining a new operating speed and controlling the water pump-turbine set to operate at the new operating speed so that the water pump-turbine set operates at the new operating speed Wherein f e is the hydraulic excitation frequency, f n is the modal frequency, and δ is a safety margin threshold.
2. The method of claim 1, wherein the establishing a fluid-solid coupling model of the water pump-turbine set comprises: And establishing a fluid model and a structural solid model of a full flow channel comprising a rotating wheel, a main shaft, a movable guide vane, a top cover, a seat ring, a volute and a draft tube of the water pump turbine unit.
3. The method of claim 1, wherein the calculating, by using an acoustic-solid coupling modal analysis method, the modal parameters of the fluid-solid coupling model of the water pump-turbine set in the water environment comprises: And setting a fluid domain of the fluid model as a compressible acoustic medium, setting a structural domain of the structural solid model as a solid medium, setting coupling conditions on a coupling interface of the fluid model and the structural solid structure, and carrying out modal analysis and solving to obtain the natural frequency of the set order of the fluid-solid coupling model of the water pump-turbine unit in a water body environment.
4. The method according to claim 1, wherein the calculating the hydraulic excitation frequency of the water pump-turbine set according to the current operation speed or the expected operation speed of the water pump-turbine set comprises: And determining the hydraulic excitation frequency according to a calculation formula f e =k×N/60, wherein k is the number of blades or the number of movable guide blades of a runner of the water pump water turbine unit, and N is the current running speed or the running speed expected to be implemented of the water pump water turbine unit.
5. The method of claim 1, wherein the safety margin threshold has a value in the range of 5% -15%.
6. The method of claim 1, wherein the determining a new operating speed comprises: Determining a plurality of operation speeds to be selected within the allowable speed range of the water pump turbine unit; Calculating to obtain the hydraulic excitation frequency and the output power of the water pump turbine set when the water pump turbine set runs at each operation rotation speed to be selected; And selecting one of a plurality of operation rotating speeds to be selected, wherein the difference between the hydraulic excitation frequency of the water pump and water turbine unit and the modal frequency is the largest, and the variation of the output power is within a set range, and determining the one as the new operation rotating speed.
7. A vibration control system for a variable speed water pump turbine unit, comprising: The modeling analysis unit is used for establishing a fluid-solid coupling model of the water pump-turbine unit, and calculating to obtain modal parameters of the fluid-solid coupling model of the water pump-turbine unit in a water body environment by adopting an acoustic-solid coupling modal analysis method, wherein the fluid-solid coupling model comprises a fluid model and a structural solid model of the water pump-turbine unit in the water body environment, and the modal parameters comprise natural frequencies with set orders; The control unit is electrically connected with the modeling analysis unit and is used for calculating the hydraulic excitation frequency of the water pump-turbine unit according to the current running speed or the running speed expected to be implemented of the water pump-turbine unit, determining the natural frequency closest to the hydraulic excitation frequency from the modal parameters as the modal frequency, comparing the modal frequency with the hydraulic excitation frequency, and when Determining a new operating speed and controlling the water pump-turbine set to operate at the new operating speed so that the water pump-turbine set operates at the new operating speed Wherein f e is the hydraulic excitation frequency, f n is the modal frequency, and δ is a safety margin threshold.
8. The system of claim 7, wherein the modeling the fluid-solid coupling of the water pump-turbine unit comprises: And establishing a fluid model and a structural solid model of a full flow channel comprising a rotating wheel, a main shaft, a movable guide vane, a top cover, a seat ring, a volute and a draft tube of the water pump turbine unit.
9. The system of claim 7, wherein the calculating, by using the acoustic-solid coupling modal analysis method, the modal parameters of the fluid-solid coupling model of the water pump-turbine set in the water environment comprises: And setting a fluid domain of the fluid model as a compressible acoustic medium, setting a structural domain of the structural solid model as a solid medium, setting coupling conditions on a coupling interface of the fluid model and the structural solid structure, and carrying out modal analysis and solving to obtain the natural frequency of the set order of the fluid-solid coupling model of the water pump-turbine unit in a water body environment.
10. The system of claim 7, wherein the calculating the hydraulic excitation frequency of the water pump-turbine set based on the current operating speed or the expected operating speed of the water pump-turbine set comprises: And determining the hydraulic excitation frequency according to a calculation formula f e =k×N/60, wherein k is the number of blades or the number of movable guide blades of a runner of the water pump water turbine unit, and N is the current running speed or the running speed expected to be implemented of the water pump water turbine unit.
11. The system of claim 7, wherein the safety margin threshold has a value in the range of 5% -15%.
12. The system of claim 7, wherein the determining a new operating speed comprises: Determining a plurality of operation speeds to be selected within the allowable speed range of the water pump turbine unit; Calculating to obtain the hydraulic excitation frequency and the output power of the water pump turbine set when the water pump turbine set runs at each operation rotation speed to be selected; And selecting one of a plurality of operation rotating speeds to be selected, wherein the difference between the hydraulic excitation frequency of the water pump and water turbine unit and the modal frequency is the largest, and the variation of the output power is within a set range, and determining the one as the new operation rotating speed.
13. A computer system comprising one or more processors and memory storing computer program instructions that, when executed by the processors, implement the method of any of claims 1-6.

Description

Vibration control method and system for variable-speed water pump turbine unit Technical Field The application relates to the technical field of hydraulic mechanical vibration and control, in particular to a vibration control method and system of a variable-speed water pump turbine unit. Background Along with the transformation of the energy structure, the pumped storage power station has increasingly prominent effect in the peak regulation and frequency modulation of the power grid. In order to improve the operation efficiency and the response capability to a power grid, a variable speed constant frequency water pump turbine unit has become a development trend. However, variable speed operation means that the unit will experience a broader range of rotational speeds, with the frequency of hydraulic excitation produced by its rotating components (e.g., the wheel) also varying. When the changed excitation frequency is coincident with a certain natural frequency of a unit structure (including a water body in a runner), strong structural resonance is induced, so that the unit vibration and noise are increased sharply, the safe and stable operation of the unit is seriously threatened, and even structural fatigue damage is caused. The existing vibration control methods are mostly 'passive', namely, after vibration occurs, a specific rotating speed point is avoided through a reinforcing structure, a dynamic damper is installed or post analysis is carried out. These methods have hysteresis and cannot accommodate widely and dynamically varying operating conditions of the transmission. The traditional modal analysis only considers the dry mode of the structure in the air, but omits the additional mass effect of surrounding water, so that the calculated natural frequency is higher, the deviation from the actual situation is larger, and the reliability of the vibration-proof strategy formulated according to the method is insufficient. Disclosure of Invention The invention aims to overcome the defects of the related art, and provides a vibration control method and a vibration control system for a variable-speed water pump turbine unit, which can accurately calculate the real mode of the unit in a water body, actively regulate and control the rotating speed to avoid resonance, thereby realizing active and intelligent vibration inhibition. In a first aspect, an embodiment of the present application provides a vibration control method of a variable speed water pump turbine unit, including: Establishing a fluid-solid coupling model of the water pump turbine unit, and calculating to obtain the modal parameters of the fluid-solid coupling model of the water pump turbine unit in a water body environment by adopting an acoustic-solid coupling modal analysis method, wherein the fluid-solid coupling model comprises a fluid model and a structural solid model of the water pump turbine unit in the water body environment, and the modal parameters comprise natural frequencies with set orders; According to the current running speed or the running speed expected to be carried out of the water pump turbine unit, calculating to obtain the hydraulic excitation frequency of the water pump turbine unit, and determining the natural frequency closest to the hydraulic excitation frequency from the modal parameters as the modal frequency; comparing the modal frequency with the hydraulic excitation frequency when Determining a new operating speed and controlling the water pump-turbine set to operate at the new operating speed so that the water pump-turbine set operates at the new operating speedWherein f e is the hydraulic excitation frequency, f n is the modal frequency, and δ is a safety margin threshold. Optionally, the establishing a fluid-solid coupling model of the water pump-turbine unit includes: And establishing a fluid model and a structural solid model of a full flow channel comprising a rotating wheel, a main shaft, a movable guide vane, a top cover, a seat ring, a volute and a draft tube of the water pump turbine unit. Optionally, the calculating to obtain the modal parameters of the fluid-solid coupling model of the water pump turbine unit in the water environment by adopting the sound-solid coupling modal analysis method includes: And setting a fluid domain of the fluid model as a compressible acoustic medium, setting a structural domain of the structural solid model as a solid medium, setting coupling conditions on a coupling interface of the fluid model and the structural solid structure, and carrying out modal analysis and solving to obtain the natural frequency of the set order of the fluid-solid coupling model of the water pump-turbine unit in a water body environment. Optionally, the calculating to obtain the hydraulic excitation frequency of the water pump turbine unit according to the current running speed or the running speed expected to be implemented of the water pump turbine unit includes: And determining the hydraulic