Symmetrical Components of Transmission Line Parameters based on the Installed Tower Ground Resistivity

Abstract

Transmission is a component of the electric power system alongside the generation and distribution systems. Effective and efficient planning is often required in system design and operation to ensure consistent and reliable supply of power to the Customers. Thus, transmission line parameters analysis needs to be carried out to ensure this proper planning. One of the crucial equipment used in transmission’s overhead lines is Tower supports which are of different configuration considering the Structural design, voltage ratings and current transmission. Very often, towers are randomly installed to carry lines of the chosen voltage and current rating without considering the effects of earth resistivity on which the tower is installed. This paper presents the transmission line symmetrical component parameters evaluation of a chosen Transmission tower. An algorithm was developed, and python software program was used to implement this algorithm for the analysis. In achieving target, the selected tower was imagined having been erected on six different earth resistivity ground which include, sea water, swampy ground, pure slate, sandstone and general average ground. Symmetrical component parameters evaluated includes impedance, characteristics impedance, propagation constant, shunt admittance and capacitive suceptances as they were found to be important in the effective monitoring of power transmission and distribution. The results of the analysis are presented and discussed. These results show that capacitive suceptances are independent on tower earth resistivity and vary for different tower structural configurations while other parameters vary with earth resistivity value of the tower. Furthermore, regular line parameters monitoring is a measure minimizing power transmission losses in networks.