Analysis of Suppressing Methods and Influencing Factors of High Voltage Cable Circulating Current Based on ATP-EMTP

Abstract

With the high-speed development of urban power system in China, the application of single-core cables in urban transmission and distribution grids is more and more extensive. Excessive circulating currents, generated on the metal sheath of single-core high-voltage cable, bring massive loss which will reduce cable transmission efficiency and safe operating lifetime. In this paper, the cable with cross-bonding mode was established based on ATP-EMTP. Through the simulation analysis, the relationships between the circulating current and the arrangement, segment and core current were obtained. The variations of circulating current and sheath voltage in case of the cable faults (short circuit, open circuit, commutation failure) were discussed. And the suppressing methods by using the series resistance, inductance and impedance were proposed to restrain the circulating currents. The results obtained show that the circulating currents are linearly related to the section length, arrangement and core current, which change significantly in case of short circuit, open circuit and commutation failure. The series resistance and inductance have effective suppressing effects not only on the steady state circulating currents but also on the transient circulating currents. The series inductance can make the circulating currents change smoothly