A Feasibility Study of Transformer Winding Temperature and Strain Detection Based on Distributed Optical Fibre Sensors

Abstract

The temperature distribution and deformation of the transformer windings cannot be measured in a distributed manner by the traditional method and failure location cannot be performed. To solve these problems, we present a transformer winding temperature and strain based on a distributed optical fibre sensing detection method. The design of the optical fibre winding composite model is developed and simulated winding temperature rise test and local deformation test distinguish between measuring the winding temperature and the strain curve. The test results show that the distributed optical fibre can transmit wire strain efficiently. Optical fibres, in the process of winding, have a certain pre-stress. Using the Brillouin–Raman joint measuring method, one can effectively extract the optical fibre temperature and strain information and measure the length of the winding direction of the temperature and strain distribution curve to a temperature measurement precision of ±2 °C and strain detection accuracy of ±50 με. The system can carry out local hot spot and deformation localisation, providing new ideas for the transformer winding state monitoring technology.

Transformer Winding Deformation Detection Based on BOTDR and ROTDR

“…Liu et al [16] designed a scheme for grooved winding with a sensing fiber in it, then using ROTDR and BOTDR to detect the winding deformation. However, the design of the slotted wire has greatly changed the structure of the wire, which has reduced its ampacity and short-circuit resisting ability, and it is difficult to extract the fiber in the actual production process of the transformer.…”

Review of optical fibre sensors for electrical equipment characteristic state parameters detection

“…A liquid-core sensing fibre, usually a glass tube (the cladding) filled with an ultra-transparent liquid of high refractive index, is commonly used to generate bigger change in η(z). (b) BS-based fibre temperature sensor [154][155][156][157][158]: The temperature perturbations affect the refractive index of the sensing fibre, thus changing the Brillouin frequency shift ν B , according to the equation [159]:…”

“…The equation indicates that BS-based fibre sensor can also be used to detect distributed strain along the sensing fibre. (c) RS-based fibre temperature sensor [160][161][162][163][164]: Since Anti-Stokes RS is much more sensitive to temperature than Stokes RS, the ratio of Anti-Stokes and Stokes Raman-scattered light intensities provides valuable information on temperature perturbations, according to the equation [159]:…”

“…(b) BS‐based fibre temperature sensor [154–158]: The temperature perturbations affect the refractive index of the sensing fibre, thus changing the Brillouin frequency shift ν B , according to the equation [159]: where ν B ( ν B0 ) is the Brillouin frequency shift at temperature T ( T 0 ) and strain ɛ ( ɛ 0 ), C vT and C vɛ are the temperature and strain response coefficients of the Brillouin frequency shift, respectively, ΔT and Δɛ are the changes relative to the initial temperature and strain, respectively. The equation indicates that BS‐based fibre sensor can also be used to detect distributed strain along the sensing fibre.…”

Design and Performance Test of Transformer Winding Optical Fibre Composite Wire Based on Raman Scattering

“…The frequency of elastic scattered light is the same as the frequency of the incident light, whereas the frequency of inelastic scattered light is offset from the frequency of the incident light. The study found that the scattering of light in the fibre includes Rayleigh scattering, Brillouin scattering and Raman scattering (Figure 1) [22]. Rayleigh scattering is elastic, whereas Brillouin scattering and Raman scattering are inelastic.…”