Transducers for electrical apparatus insulation online monitoring

This paper presents detail analysis on transducers used for online monitoring system for electrical apparatus. Transducers are the key components of the online monitoring system; they play important roles on the stability and accuracy of monitoring results. Two types of transducers are discussed in this paper - the transducers used for dielectric loss angle measurement and the ones for partial discharge measurement. Basically their characteristics can be derivative from a uniform equation according to the materials used and structure, but the aspect differs from the frequency domain and time domain analysis. The transfer function of the transducers is put forward, the phase-frequency, amplitude-frequency characteristics are discussed and the time-domain response is concluded from unit pulse response convolution. The structure, shielding are also mentioned. For the characteristics may be changed with the temperature shift, the error analysis is implemented to compensate the result. The results of the field test have proven the stability and feasibility, and these transducers can be used for electrical apparatus insulation online monitoring.