FDTD modeling of UHF partial discharge sensor response

Ultra high frequency (UHF) partial discharge sensors are valuable tools for condition monitoring of high voltage equipment. This paper explores the effectiveness of the finite difference time domain (FDTD) numerical modelling technique as a means to support the design and optimisation of these sensors. The responses a monopole, a planar logarithmic spiral and a novel helical spiral sensor to a step electric field have been obtained both empirically, using a gigahertz transverse electromagnetic test cell, and through software modelling by means of the FDTD technique. Results indicate that FDTD modelling can achieve a reasonably accurate prediction of UHF partial discharge sensor response provided specific environmental electromagnetic conditions are met and the model geometry is an acceptable trade-off between accuracy and simulation time. This software-based approach may prove a useful additional tool in UHF sensor design process.