The researches on the monitoring and positioning of partial discharge in open-type substations are available in the literature, but existing utral high frequency (UHF) partial discharge (PD) localization systems are mainly based on time-difference of electromagnetic wave signal, in which the synchronization accuracy and sampling rate are highly required, thus its use and promotion are restricted to a degree. We propose a received signal strength indicator (RSSI)-based angle-of-arrival (AoA) method using the monopole UHF wireless sensor array. Multiple antennas are evenly placed in a circle frame and form an antenna array. Then an AoA estimation scheme is derived through the radiation pattern of designed UHF antenna. Interpolation, clustering and neural network are applied to improve the AoA resolution. A laboratory test is performed to verify the effectiveness of the proposed PD localization system. The results show that the estimated error on average is below 9°. Compared to the accuracy of the time-difference-based method, the accuracy of the designed system in this paper is more feasible for practical application considering its significant low-cost feature. The research can provide references for the monitoring of partial discharge signals. © 2020, High Voltage Engineering Editorial Department of CEPRI. All right reserved.
