Design and Implementation of an RF Module for UHF PD Measurement

Ultra high frequency (UHF) partial discharge (PD) measurement method outperforms the conventional method in some cases, such as better sensitivity, immunity against external disturbances, 3D localization and online monitoring. Despite the advantages of the UHF method, capturing PD in the frequency range of UHF is challenging. Firstly, UHF range measurement needs instruments with high sampling rate that raises the operating costs. Furthermore, the instruments of conventional PD measurement method are incompatible with UHF technique. To overcome the issue, an interface module is required to convert the UHF range of PD signals to lower frequencies within the range of the conventional method. This paper describes the development and evaluation of a down-converter module, followed by testing in a high-voltage laboratory to measure actual partial discharge (PD) occurrences within a transformer enclosure. The findings exhibit promising results in detecting PD events and generating phase-resolved partial discharge (PRPD) diagrams through the newly introduced interface module.