Impact of high-frequency switching on cable insulation: Fast-acting switching components at Back-to-Back intertie produce high frequencies that may cause insulation breakdown

摘要

ABB, American Electric Power (AEP) and EPRI documented the impact of high-frequency switching on cable terminations used for the converter-based Eagle Pass Back-to-Back (BtB) installation located at Eagle Pass Substation on the AEP (Columbus, Ohio, U.S.) transmission system. Fast-acting switching of high-power semiconductor switches results in steep voltage steps, which have high-frequency harmonic-voltage contents. Although these high-frequency harmonics have low-voltage amplitudes and low-energy contents, they may cause stress on certain insulation materials. These harmonics also may excite local resonance and thereby may cause voltage harmonics with appreciable amplitudes. Rapid degradation of specific insulation materials has been detected and investigated through site measurements and laboratory tests. Considerable data have been collected to understand and avoid this type of insulation degradation.