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Research Of Strain Monitoring Key Technology For Wind Turbine Blade Based On Fiber Bragg Gratings

Posted on:2013-09-24Degree:MasterType:Thesis
Country:ChinaCandidate:J Z ChenFull Text:PDF
GTID:2248330371995711Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
Nowadays, more and more strain sensor equipments are used in wind power systems to prevent the damage of wind turbine blade, and reduce the economic losses. On the other hand, with the development of the fiber technology, the sensors especially the fiber Bragg grating (FBG) sensors have been attracted increasing interesting due to the high precision, long service life and electromagnetic interference immunity. Therefore, forcus on the software design and signal processing, this paper has investigated the high-speed demodulation scheme for wind turbine blade based on FBG sensing by using the time division multiplexing (TDM) and wavelength division multiplexing (WDM) technologies, which can realize the quasi distribution strain monitoring successfully.Firstly, this paper focuses on the basic principle of FBG sensors and multiplexing technologies, and then we have compared the superiorities and deficiencies of TDM and WDM. By using TDM and WDM technologies simultaneously, we proposed a quasi distribution strain monitoring scheme for wind turbine blade. Successively, we give the overall framework of the hardware design and introduce the mechanical structures in detail, including mainframe-box, motherboard, and FBG plate. Moreover, the design of software has been analyzed from peak detection and filtering. In order to reduce the influence of the optical and electrical noise, three algorithms including average filtering, composite filtering and Kalman filtering have been investigated, respectively. Furthermore, these three filter schemes are repectively compared from the system rate, dynamic range, stability and efficiency by experiment. Finally, the feasibility of our system has been experimentally demonstrated, whose superiorities and deficiencies are also summarized.The main contributions in this paper are as follows:(1) The static simulation experiment with strain is carried out, which demonstrates that the system can monitor the distribution of the blade strain sensitively.(2) By using hardware filtering and software filtering simultaneously, the better signal processing performance of the demodulation system can be realized. Take the system stability, dynamic range, operation efficiency and the complexity into account, the composite filtering algorithm is more suitable for our system in certain data rate.(3) The post-data of digital signal processing (DSP) can be delivered to the PC by RS232, USB port or Ethernet interface. Consequently, the remote control for the system is realized, with the strain values displayed graphically.
Keywords/Search Tags:Fiber Bragg grating (FBG), Time division multiplexing (TDM), Wavelengthdivision multiplexing (WDM), Composite filtering algorithm, Kalman filtering
PDF Full Text Request
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