Analysis of Conducted Disturbance via Current Transformer Due to Switch Operation of GIS Disconnector in UHV Substation

作者：Zhao, Jun; Chen, Weijiang; Li, Kejie^*; Teng, Zihan; Li, Ni; Wen, Tao; Fan, Xing

来源：CSEE Journal of Power and Energy systems, 2023, 9(3): 1227-1234.

DOI：10.17775/CSEEJPES.2021.05580

• Integrated circuit modeling
• Windings
• Substations
• Current measurement
• Insulators
• Soil
• Impedance
• Conducted disturbance
• current transformer
• switch operation
• simulation
• UHV substation

The characteristics of conducted disturbances via current transformer (CT) caused by switch operations in 1000 kV UHV substations are studied in this paper. Since the broad-band circuit models might have limitations on the stability and accuracy for CT conducted disturbance simulation, a frequency-domain simulation method without circuit synthesis is proposed based on VFTC spectrum and CT transfer characteristics. To improve VFTC simulation accuracy, both the bushing radiation loss and frequency-dependent earth impedance are taken into consideration. Transfer characteristics of three types of windings for the 1000 kV GIS CT are ingeniously measured from a combination of fast and slow impulse tests. Through conducted disturbances simulations in UHV Wuhu substation, bushing radiation loss is found to have a suppression effect on the high-frequency response but the effect of frequency-dependent earth impedance can be ignored. As a result, the maximum amplitude of 84.5 A for the conducted disturbance is obtained, thus a fast damped oscillatory wave immunity test with no lower than Level 4 from IEC standard is suggested to test the anti-interference performance of the secondary equipment in UHV substation.

• 单位
  国网电力科学研究院; 西安交通大学