Performance of medium voltage cable terminations under high frequency voltage waveforms

Field experiences have shown that transmission systems using voltage sourced converters can produce high frequency harmonic resonances in the VSC station environment. Modern XLPE cable terminations using non-geometric stress grading can be susceptible to degradation under these harmonics. The paper presents the high frequency voltage effects in XLPE cable terminations, under conditions that are representative of high frequency (HF) harmonic resonance in a VSC system. Results reveal a wide variation in electrical and thermal behaviour among termination designs, under HF conditions. These variations are related to stress grading system and material properties.