Design of Counterpoise Grounding Electrodes Encased with Low Resistivity Material for Transmission Towers

This paper presents design of counterpoise electrodes encased with earthing enhancing compounds or more effective grounding (MEG) for transmission towers. Approach is based on a full-wave electromagnetic analysis. For counterpoise analysis, the partial element equivalent circuit (PEEC) is used. In this paper, we use lightning parameters from IEC 62305 as reference. For normal case, the soil ionization and frequency dependent parameters are ignored. In cases high ground resistivity more than 1000 ohm-meter, grounding of long counterpoise makes the capacitive result, this make electrode impedance lower than resistance. The impulse impedance of the four-leg and eight-leg counterpoise electrode in area which is high ground resistivity of 5000 ohm-meter, grounding impedance cannot be achieved because of the result of effective length. The MEG is encased with the eight-leg grounding electrode impedance can be accomplished.