Application of sleeve monopole antenna for partial discharge detection in transformer

Based on the structure of power transformer, a sleeve monopole antenna for partial discharge detection in transformer was designed. In this paper, the structure of the antenna is described, the calculation principle and method of the antenna parameters are presented. Through optimizing the structure parameters, which change the input impedance of the antenna, good VSWR characteristic, high gain and steady pattern are obtained. According to simulation analysis and actual measurement, the bandwidth of the antenna is 350~500 MHz, and the center~equency is 425 MHz, the average gain reaches 2.16 dBi and varies little in the whole bandwidth. The laboratory measurement result shows that the sleeve monopole antenna can satisfy the requirement of partial discharge detection, and detect the partial discharge signals in effective band with high sensitivity and good directivity.