Earthing System

1. A transformer works on the principle of: A) Self inductionB) Mutual inductionC) Eddy currentD) Hysteresis Answer: BExplanation: A transformer has a core on which the primary and secondary windings are wound. When the primary winding is energized, it draws a magnetizing current and produces magnetic flux in the core. This flux links with both … Read more

A power substation requires the earthing system for three main purposes. The purpose of earthing is to keep any voltage on metal frameworks below dangerous levels during normal or fault conditions. In directly earthed neutral system, it is not always possible to keep metal parts exactly at true earth potential when fault current flows. Therefore, … Read more

Scientists have proposed various theories to explain how electric charges form and separate inside clouds. In reality, charge formation and separation inside clouds are very complex natural phenomena. Engineers mainly need to know that charge separation occurs in thunderstorm clouds. In general, the negative charge concentrates in the main lower part of a thundercloud. In … Read more

Eriksson Striking Distance Equation The earlier equation, which relates striking distance to return stroke current, does not imply everything. Because the earlier lightning models assumed that the striking distance depends only on the return stroke current. However, Eriksson found this was not a fully correct prediction. He showed that the height of the structure also … Read more

Empirical design methods protect substations and transmission lines from lightning using practical experience. The two methods are fixed angles and empirical curves. Both give acceptable protection. Fixed Angle Method of DSLP Here, we assume that a lightning mast or shielding wire protects an area below it within a fixed angle. It saves all equipment inside … Read more

Organized into 15 categories Current Transformer (CT) Potential Transformer (PT / VT / CVT) Circuit Breakers (VCB / SF6 / GIS / ACB / OCB) Protection Systems Substation Engineering (AIS/GIS) Earthing & Lightning Protection Transformer Engineering Capacitor Banks & Power Quality Transmission Lines Distribution Systems HVDC & FACTS Industrial Systems Standards & Testing Real-World Operation … Read more

To design the proper grounding systems for transmission line towers, we need to know the soil resistivity. Here, we shall provide a comprehensive guide. Wenner Four Point Method We follow the IEEE 81 Standard for soil resistivity measurement for this purpose. We need the following equipment for the measurement. Step-by-Step Procedure Select Test Location: We … Read more

Measuring soil resistivity is essential before designing a grounded earthing system for a substation. Because this measurement determines how well the ground can dissipate fault currents. If the soil resistivity is high, the grounding system needs some changes. It requires denser earthing mesh and more conductive electrodes. A well-designed earthing system prevents intolerable voltage buildup. … Read more