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.