Analysis of Simulated Partial Discharge Waveform and Converter Noise for the Partial Discharge Diagnosis in HVDC MI Submarine Cable

This Partial discharge diagnosis in HVDC (High Voltage Direct Current) MI (Mass Impregnated) submarine cables is very difficult due to the attenuation of partial discharge signals in magnitude and frequency during the propagation through long-distance line. Nevertheless, since partial discharge signals are large and wide due to the degradation characteristics of MI cable insulation compared with XLPE (Cross-linked polyethylene) cable systems, propagated partial discharge signals may be detected if measured in a low frequency band. However, partial discharge measurement becomes very complicated and difficult due to noise in the converter station. In this study, noise characteristics were analyzed by measuring conversion noise, and the propagated characteristics of the partial discharge signal generated in a distant location were analyzed using EMTP (Electro Magnetic Transient Program) with the experiment for the model. By comparing these simulated partial discharge signals with noise signals measured in the converter station, the possibility of partial discharge diagnosis of HVDC MI submarine cables was examined.