Improvement on measurement sensitivity of the optical remote sensing based PD continuous on-line monitoring system for HV cable joints

This paper investigates the improvement on measurement sensitivity of the electro-optic modulator based PD continuous online monitoring technique, which has been developed by the authors. The characteristics of the measurement system noise were investigated in both the time and frequency domain. Various broadband amplifiers and filters have been applied. The feasibility of using RF transformers as passive amplifiers to increase the signal to noise ratio was also investigated.