Statistical correlation between partial discharge pulses magnitudes measured in the HF and UHF range

Partial discharge (PD) detection using antennas has become a useful technique for condition monitoring of high-voltage equipment. However, one of its main drawbacks is the lack of knowledge for the quantification of the PD magnitudes, which is possible when conventional capacitive dividers or high-frequency current transformers (HFCT) are used. This paper studies a possible relation between PD pulses measured in the HF and RF range. Different types of PD events were measured in the HF range using an HFCT and in the VHF/UHF range using two types of antennas. The peak value and the energy of each PD pulse have been studied for both HF and radio-frequency (RF) sensors, representing them in graphics. In addition, the possible statistical dependence between variables (peak-energy; peak-peak; energy-energy) has also been quantified.

I. Introduction

Partial discharges are phenomena with strong relationship with the degradation of the electrical insulation of electric power equipment. For that reason, its accurate measurement is a strong research topic within condition monitoring [1].