Q2Power System - I
Question
Q.2. What are the effect of Electric and Magnetic Field in Transmission Line?
Answer
The electric field around a transmission line causes charging current, capacitive coupling and induced voltages on nearby conductors, while the magnetic field (from load current) induces circulating currents and voltages in nearby conductors and can interfere with communication lines.
The electric field surrounding an energized transmission line, arising from the conductor voltage, produces capacitive charging current in the line itself, causes electrostatic induction (induced voltage) on nearby unenergized conductors, fences, or vehicles, and gives rise to corona effects at high voltage gradients near the conductor surface. The magnetic field, arising from the current flowing in the conductors, produces electromagnetic induction in nearby parallel conductors (such as telecommunication lines or pipelines), which can cause interference, induced circulating currents and safety hazards during both normal operation and fault conditions, and also contributes to the line's series reactance (inductance) that affects voltage drop and power transfer capability.