Robust on-line partial discharge measurement of 35-kV cables in wind farms via dual sensors

Abstract

Condition-based maintenance of cables in wind farms is critical for their operation reliability and stability. A promising solution to this task is to carry out on-line partial discharge measurement on the cables. However, impulse noise interferences from wind turbines or adjacent overhead lines could severely reduce the sensitivity of in field partial discharge measurement. Accordingly, this paper proposes a robust method to recognize the harmful partial discharge signal from the severe impulse noise. The method is based on joint analysis of the noisy partial discharge signals detected by two non-invasive partial discharge sensors, which are mounted on the double sides of the cable or on its terminal. The noiseless partial discharge signal and the impulse noise can be separated well via performing statistical clustering analysis on the pulse source location map or peak ratio vector obtained from the two detected noisy signal sequences. Finally, the effectiveness and feasibility of the proposed method is validated on two real partial discharge-affected 35-kV cables in an onshore wind farm.