Bolt on-line monitoring system and method of wind power generating unit

Abstract

The invention belongs to the technical field of wind power generators, and discloses a bolt on-line monitoring system and method of a wind power generating unit. The bolt on-line monitoring system comprises an optical fiber sensor connected with bolts on a wind power generator, a signal processing system connected with the optical fiber sensor, a display device connected with the optical fiber sensor and an alarm which conveys early warning information to workers. The bolts are connected with the optical fiber sensor with probing optical cables, the signal processing system receives the optical signals sent out by the optical fiber sensor and carries out data analysis and processing, and the display device is used for data displaying, testing and early warning. By using the optical fiber sensor, long-distance distributed monitoring and real-time monitoring of the multiple bolts can be realized. In addition, the coding technique is introduced to the signal processing system to conduct sequence coding on optical pulse signals before the optical pulse signals are injected to measured optical fibers, the limitations of a traditional moving average method are avoided, the signal to noise ratio of the signal processing system is increased, and the dynamic measurement range of a double beam optical time domain reflectometer (OTDR) is enlarged.

Description

technical field [0001] The invention belongs to the technical field of wind power generators, and in particular relates to an online monitoring system and method for bolts of a wind power generator set. Background technique [0002] At present, the existing technologies commonly used in the industry are as follows: After long-term operation and rotation of the wind power generator set, some bolts will loosen, fall off or break. The bolts that fix the blades of the wind power generator are located at a height of tens of meters. Loose and falling bolts cannot be replaced in time, and there are many bolts on the wind turbine. In the prior art, simultaneous online monitoring and positioning of multiple bolts on the wind turbine cannot be realized. In the on-line monitoring system and method of bolt fastening degree based on OTDR technology, according to the light intensity data of the optical time domain reflectometer, it can be judged whether the bolt is loose or falling off, ...

AI Technical Summary

Problems solved by technology

[0005] In summary, the problems in the prior art are: The detection sensitivity of the existing on-line monitoring method of bolt fastening degree based on OTDR technology is more affected by the line width of the light source, and there is always a blind area during use, and the blind area will increase with the increase of the pulse width. Wide-range pulses should be used for measurement, but increasing the pulse width will reduce its resolution and detection sensitivity, and it is applied to the monitoring of wind turbine bolts, which is affected by the noise of the surrounding environment and has a great impact on the detection results.

Although this technology has a good effect on reducing the blind area, it is more complicated to implement. It is necessary to set shielding points in all places where there are reflected signals. It will be difficult to adjust the parameters and the cost will be high.

[0008] From the design point of view of OTDR itself, OTDR can provide better blind zone performance when transmitting short pulses, but its dynamic range will be reduced, which is not suitable for long-distance and large-range objects such as wind power generators. Some manufacturers place them inside the instrument. A variable optical attenuator is used to control the optical power through the attenuator to reduce the power of the reflected optical signal and reduce the saturation of the receiver to obtain a smaller blind area, but this method is also at the expense of the instrument At the expense of the dynamic range, it cannot be applied to the monitoring of long-distance wind turbines

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