MONITORING SYSTEM OF INTERNAL TEMPERATURE AND STRESS OF POWER TRANSFORMER WINDING AND MONITORING METHOD THEREOF

摘要

A system for monitoring the internal temperature and the stress of a power transformer winding, comprises a laser light source (8), an optical fiber sensor, a frequency shift detection circuit, an amplification circuit, a filtering and sampling circuit and a display (12). A method for monitoring the internal temperature and the stress of a power transformer winding involves: light emitted from the laser light source (8) passes through the optical fiber sensor and generates Brillouin scattering; the optical fiber sensor is pre-embedded in the electromagnetic wire of the power transformer winding; the frequency of Brillouin scattering signal of the optical fiber sensor is influenced by the internal temperature and the stress of the power transformer winding; the Brillouin scattering signal sent back by the optical fiber sensor is transformed into an electric signal by the frequency shift detection circuit; the electric signal passes through the amplification circuit and the filtering and sampling circuit to obtain the information of the internal distributed temperature and the stress of the winding; the information of the internal distributed temperature and the stress is finally sent to the display (12). The system can accurately detect the temperature and the stress in the transformer winding, thus truly reflecting the temperature and the stress of the hottest point of the winding.