Researches On The Environmental Insensitive Optical Voltage Sensor Based On The Compensation Of Ground Potential Crystal

Optical voltage transformers, based on Pockels effect, can measure voltage in high accuracy. Compared with traditional voltage transformers, optical voltage transformers have advantages in measuring range, transient characteristics, insulation, device volume, suppressing electromagnetic interference etc. However, the measuring accuracy of the optical voltage transformers were influenced by environmental factors especially temperature and pressure in practical application, so it was difficulty to keep stability in long term operation and this hindered the process of practical application of optical voltage transformer. In this paper some researches were done on how to improve the environmental stability of the optical voltage sensor.In this paper, the basic principle of optical voltage sensor was analyzed and then the methods usually taken to improve the optical voltage sensor stability were summarized. These methods could improve the sensor stability in some part, but the principles how environmental factors affect the sensor were not analyzed in depth. In this paper the principles were analyzed how environmental factors affect the sensor and the sensor under environmental factors was simulated in ANSYS. According to the simulation, the environmental influences were quantified. Based on these analysis, a new sensing structure which is not immune to environmental factors was proposed. After proving the validity for environmental stability of this new sensing structure with Jones matrix method, a prototype of this sensor was produced and then tested for linearity, temperature stability and pressure stability.The experimental results show the ground potential crystal compensation structure can improve the sensor environmental stability, and has positive significance for improving the stability of the optical voltage transformer.