Analisis Keamanan Pentanahan Grid dan Proteksi Gardu Induk dengan Variasi Arus Surja Petir Menggunakan Software ATP-Draw

Abstract

Substations are essential components in electrical transmission systems and are highly susceptible to disturbances, particularly from lightning strikes both direct and indirect. To safeguard equipment and ensure operational safety, a protection system is necessary. One such method is the grounding system, which should ideally exhibit low soil resistivity. The accuracy of soil resistivity measurements is influenced by the type of soil and the design of the grounding grid configuration. This study investigates grounding systems with and without square-shaped ground rods, including an assessment of touch and step voltages on two-layer soil, as well as arrester modeling in accordance with IEEE standards. Overvoltage simulations caused by lightning strikes were conducted using ATP-Draw software, incorporating various grid configurations based on conductor spacing and length. The calculation results yielded K coefficient values both below and above zero, but still within the safety limits defined by substation design standards. Additionally, the simulation demonstrated that lightning arresters effectively protect the transmission system, achieving a protection factor (PF) of 22.15%.