Development of a Method for Calculating the Transmission-line Constants of a Three-phase Enclosure-type Gas Insulated Bus Taking the Proximity Effect into Account

Abstract

Accurately calculating the transmission-line constants of underground cables and gas insulated bus (GIB) is important for various types of power system simulations. When calculating the transmission-line constants of a three-phase enclosure-type GIB, the Cable Constants supporting routine of EMTP is usually used. However, this routine could cause numerical errors, since the proximity effect is ignored for the calculation of series impedances and shunt admittances. In this paper, a method for calculating the transmission-line constants of a three-phase enclosure-type GIB considering the proximity effect is proposed. Then, series impedances and shunt admittances are accurately calculated by the MoM-SO (method of moments with a surface admittance operator) and MoM (method of moments), respectively. In this paper, the proposed method is verified by experiments using the small-scale model of a three-phase enclosure-type GIB. Calculated results obtained by the proposed method agree well with the measured results.