متى تكون قيمة الجهد في بداية الخط (𝐕s) تساوي الجهد في نهاية الخط (𝐕r) و Surge Impedance Loading

Surge Impedance Loading (SIL) Why does voltage drop along a high-voltage transmission line? Is it caused only by resistance, or do inductive reactance and capacitive reactance also play an important role? In this lecture, we explain the main factors affecting voltage drop and voltage profile in high-voltage transmission lines, with a clear focus on the physical principles and practical power system applications. ⚡ What You Will Learn: The difference between voltage drop and voltage rise in transmission lines. The effects of line resistance (R) and inductive reactance (XL) on voltage drop. The role of line capacitance (C) and capacitive reactance (XC). Why capacitive effects must be considered in medium and long transmission lines. How charging current affects the voltage profile. The difference between series impedance and shunt admittance. The Ferranti Effect and why receiving-end voltage can exceed sending-end voltage. The relationship between load, power factor, and voltage regulation. The concept of Surge Impedance Loading (SIL) and its influence on transmission-line voltage. 📘 Key Engineering Concepts For short transmission lines, the approximate voltage drop depends mainly on resistance, inductive reactance, load current, and power factor. For medium and long transmission lines, shunt capacitance and charging current must also be considered to understand the complete voltage profile. This lecture is useful for electrical power engineers, transmission and distribution engineers, electrical engineering students, and professionals preparing for technical interviews and promotion examinations.