Estimation of time difference between partial discharge UHF signals using differential energy method

Partial discharge (PD) site in high voltage power equipment can be located by solving the time difference equations. Estimating the time difference between PD signals with high accuracy is of great importance for accurate locating. This paper presents a time difference determining algorithm using cumulative energy function and differential energy method. The differential energy characterize the increase of cumulative energy, and the first significant peak of the differential energy is recognized as the arrival time. After that, a Monte Carlo statistics procedure is adopted to analyze the influence of noise level on the accuracy of time difference. The proposed estimation algorithm is examined with UHF signals acquired from four antennas in laboratory. The results indicate that the algorithm is effective to determine the time difference between UHF signals.