Partial discharge detection in modern power grid

This paper presents a novel method for partial discharge detection. Generally, the presence of partial discharge in the power grid is unfavorable as it reduces the electricity transmission efficiency and also adversely affects the durability of the line. A partial discharge manifests itself as a transient voltage oscillation with a very small amplitude and a short duration. The resolution and sampling frequency of the measurement hardware must therefore be sufficient to capture these short transient signals. Furthermore, some algorithm must be able to automatically detect these transients and distinguish a true partial discharge from other components that resemble partial discharges with certain properties, but in reality, are out of interest. The first part of the article describes the properties of partial discharge signals in the frequency domain, which are further used for the discharge detection. Based on the time-frequency properties of partial discharge signals, a recursive filtering method was designed. The second part of the article shows the suitability of the proposed solution on examples of discharge detection in both test and field conditions. As will be shown, the proposed method with a high degree of reliability detects both test discharges generated in laboratory conditions and discharges that occurred during operation of the power grid