Design of a Distributed UHF Sensor Array System for PD Detection and Location in Substation.

This paper describes a distributed system for the partial discharge (PD) detection and location in the substation. The proposed system is composed of several ultrahigh-frequency (UHF) antennas located dispersedly that form an array. These antennas are connected to the central control room by the optical fiber using the radio over fiber (RoF) technique to decrease the propagation attenuation of the PD signal. The scattered layout increases the coverage of the PD signal sensing and the time difference of arrived PD signals propagating to the antennas. The signal processing part and PD location propose a virtual measurement method based on the statistical simulation. This method only uses a set of measured delay data to simulate and generate multiple sets of delay data by randomly adding the delay error, which follows a specific distribution within the limit range and uses these data to locate the PD source and statistically process the results of location. The actual positioning effect of this method is great, and the positioning accuracy and efficiency of the system are improved. The experimental results of an application case in a 220-kV substation show that this distributed UHF sensor array system can get the location accuracy of 1° when the system error of the time difference is less than 5 ns, which can meet the requirements of the PD detection and location in the entire substation. [ABSTRACT FROM AUTHOR]