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For a given receiving end voltage in a long transmission line, sending end voltage is more than the actual calculated by
Nominal ╧А method
Nominal T method
End condenser method
None of above
Nominal ╧А method
Quick Summary: In long transmission lines, the distributed parameters (R, L, G, C) are approximated using lumped parameter circuits. The Nominal $\pi$ method provides a more accurate representation of the voltage distribution and charging current compared to simpler methods, but for a given receiving end voltage, the calculated sending end voltage is higher than the actual value due to the inherent simplification of the shunt capacitance distribution.
In long transmission lines, the distributed parameters (R, L, G, C) are approximated using lumped parameter circuits. The Nominal ╧А method provides a more accurate representation of the voltage distribution and charging current compared to simpler methods, but for a given receiving end voltage, the calculated sending end voltage is higher than the actual value due to the inherent simplification of the shunt capacitance distribution.
VsтАЛ=AVrтАЛ+BIrтАЛ тАФ Transmission line ABCD parameters for sending end voltage
IchтАЛ=j╧ЙCV тАФ Shunt charging current calculation
The Nominal ╧А method lumps half of the total line shunt capacitance at each end of the line. Because the charging current, which is essential to counteract the voltage drop, is concentrated at the nodes rather than distributed uniformly along the line, the phase shift and attenuation models deviate from the exact hyperbolic solution. This approximation tends to overestimate the sending end requirements for a specified receiving end condition.
Nominal ╧А method distributes half the line capacitance at both ends.
The method is preferred for lines up to 160 km in length.
Hyperbolic equations provide the exact solution for long lines.
Nominal T method keeps capacitance at the center, whereas ╧А places it at the ends.
Simpler calculation than exact hyperbolic functions.
Reasonably accurate for medium length lines.
Less accurate than rigorous long-line models (ABCD constants).
Overestimates VsтАЛ for long transmission lines.
Power system steady-state analysis.
Transmission line performance studies.
The error in the Nominal ╧А method increases with line length.
Nominal T method also uses lumped parameters but places total shunt capacitance in the middle.
A is correct тАФ The Nominal ╧А method approximates distributed shunt capacitance as lumped values at the line ends, leading to an overestimation of the sending end voltage for a given receiving end voltage.
Always remember that for lines > 250 km, you MUST use the exact hyperbolic representation; lumped parameter models like ╧А or T only serve as approximations for medium lines.