Study on optical fiber temperature-sensing technique for vacuum circuit breaker contactor

Vacuum circuit breaker contactor material has a decided critical temperature, when the actual temperature is higher than the critical temperature, the material's dielectric strength will be declined significantly. If it cannot be found in time and taken measures, it will cause a serious accident. Therefore, the circuit breaker contactor temperature measurement is one of the important parameters in circuit breaker monitoring. But, the temperature detecting environment has the features of high-voltage, big current, strong electromagnetic interference and limited space and so on, so the temperature sensor should be high reliability, good insulation, anti-electromagnetic interference, small size and so forth, while the optical fiber temperature-sensing technique fits well with the above requirements. This paper introduces the principle of optical fiber's optical time domain reflex, elaborates the temperature -sensing principle based on Raman scattering, uses wavelet entropy to denoise the temperature signal, and designs a system for vacuum circuit breaker contactor temperature based on the optical fiber temperature-sensing technique.