Environmental characterization of an optical trigger for MV electric board

This paper analyses the temperature behaviour of an optical trigger sensor, based on a low-cost transparent electro-optic ceramic. The knowledge of the temperature behaviour is important for assessing the feasibility of this sensor as a means for accurate and safety measurements of electric parameters in Medium Voltage (MV) equipment, in addition to the previously proved its suitability for the continuous monitoring of the phase of the voltage in MV electric boards. Results of thermal tests, carried out with the optical device inserted in a climate chamber, for simulating typical thermal excursion in MV equipment, evidenced a significant sensitivity reduction of the sensor response. Nevertheless it does not affect the phase sensitivity of the sensor, this measured temperature dependence limits an accurate measure of the voltage amplitude. A linear behaviour of the characteristic parameter of the ceramic material with temperature confirms the possibility of an active temperature compensation of the sensor response.