Fan tower vibration control system and control system for increasing fan cut-out wind speed

Abstract

The invention provides a fan tower vibration control system and a control system for increasing fan cut-out wind speed. Vibration acceleration in a direction perpendicular to a windward direction of a fan wheel is introduced to a generator speed and electromagnetic torque closed-loop control circuit so as to control vibration in the direction perpendicular to the windward direction of the fan wheel; a vibration acceleration signal in the windward direction of the fan wheel is introduced to the generator speed and electromagnetic torque closed-loop control circuit so as to control windward vibration of the fan wheel; a given speed value of a generator is regulated according to wind speed measured signals so as to keep rated torque of the generator constant, and accordingly output power of the fan under the big wind condition is regulated and fan cut-out wind speed is increased.

Description

technical field [0001] The invention belongs to the field of wind power generation, and relates to a vibration suppression system for a fan tower and a control system for increasing the cut-out wind speed of a fan. Background technique [0002] When a wind turbine (Wind Turbine, MT, referred to as a fan) is running, it may cause the fan tower (also called the tower) to be in the direction perpendicular to the windward direction of the impeller (Side-side direction, which is also the direction perpendicular to the wind direction) ) produces a relatively large-amplitude first-order natural frequency vibration, and may cause the wind turbine tower to generate a relatively large-amplitude first-order natural frequency vibration in the windward direction of the impeller (Fore-aft direction, which is also the wind direction). [0003] Specifically, for the side-side direction of the tower, when the fan operates in the following stages, it will cause a relatively large first-order ...

AI Technical Summary

Problems solved by technology

[0015] (2.1) When the unit is in the grid-connected power generation mode and the generator speed is close to the minimum grid-connected speed near the cut-in wind speed, the first-order natural frequency in the Fore-aft direction of the tower is coupled with the triple frequency of the generator speed, resulting in The first-order vibration fault in the Fore-aft direction of the tower occurs;

[0016] (2.2) During the start-up process of the unit near the cut-out wind speed to the grid-connected power generation mode, due to the limitation of the wind condition, the unit maintains near the minimum grid-connected speed for a long time, also because of the tower Fore-aft direction The first-order natural frequency is coupled with the triple frequency of the generator speed, resulting in the first-order vibration fault in the Fore-aft direction of the tower;

[0017] (2.3) Above the rated wind speed, for wind turbines, since the aerodynamic damping of the first-order natural frequency in the Fore-aft direction of the tower itself is relatively small, if no measures are taken to suppress the first-order natural frequency vibration in the Fore-aft direction of the tower, During the full power operation of the unit, first, a signal with the same frequency as the first-order natural frequency in the Fore-aft direction of the tower will be excited in the generator speed signal, and the frequency signal will be used by the pitch actuator during the pitching action process , correspondingly, the aerodynamic damping of the first-order natural frequency in the Fore-aft direction of the tower becomes smaller, resulting in the first-order vibration fault in the Fore-aft direction of the tower;

[0018] (2.4) When the unit is running above the rated wind speed, due to the influence of strong gusts and rapid pitch changes, the first-order natural frequency vibration fault in the Fore-aft direction of the tower occurs;

[0020] (2.6) For the storm control strategy scheme to increase the cut-out wind speed of the unit, when the wind speed of the fan is higher than the conventional cut-out wind speed value, it is easy to cause the first-order natural frequency vibration fault in the Fore-aft direction of the tower

[0023] (2.7) This scheme can only suppress the vibration caused by the fan running above the rated wind speed, and the generator speed signal contains the same frequency signal as the first-order natural frequency in the Fore-aft direction of the tower. Below the wind speed, or the fan is running above the rated wind speed, but the generator speed signal does not include the vibration caused by the first-order natural frequency and the same frequency signal in the Fore-aft direction of the tower (that is, the aforementioned situation (2.1) , (2.2), (2.4), (2.5) and (2.6)) are powerless

[0024] (2.8) For the generator speed-pitch closed-loop control loop, the system response speed is slow, the overshoot is large, and the dynamic characteristics are poor

[0025] (2.9) The tripping condition of the air switch on the generator side mentioned in the previous situation (2.5) plays a decisive role in determining the limit load of mechanical components such as the hub of the wind turbine, the yaw bearing, the tower, and the foundation. The technical solution of adding a band-stop filter in the propeller control circuit is powerless to cause this type of vibration, so the mechanical components such as the hub, yaw bearing, tower, and foundation of the wind turbine have a large limit load, and the cost of the entire wind turbine is relatively high.

[0028] Since the existing wind turbines do not include the function of increasing the cut-out wind speed of the unit, it is impossible to increase the power generation of the unit and the investment income of the wind farm by increasing the cut-out wind speed

[0029] For the generator speed-pitch rate control loop and the generator speed-electromagnetic torque control loop of the series band-stop filter, after increasing the cut-out wind speed of the unit operation, in the process of fan startup and grid-connected power generation mode, the unit tower The vibration amplitude of the first-order natural frequency in the Fore-aft direction and the Side-side direction of the tower will increase greatly. On the one hand, it will cause vibration faults in the Fore-aft or Side-side direction of the unit. The Mx bending moment also greatly increases the corresponding fatigue load due to the increase of the vibration amplitude

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