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Ferranti effect on long overhead line is experienced when it is
Lightly loaded
On full load at unity power factor
On full load at 0.8 power factor (lead)
On any load
Lightly loaded
The Ferranti effect is the phenomenon where the receiving-end voltage of a long transmission line is higher than the sending-end voltage. It occurs primarily under light-load or no-load conditions due to the line capacitance causing a charging current.
The Ferranti effect is the phenomenon where the receiving-end voltage of a long transmission line is higher than the sending-end voltage. It occurs primarily under light-load or no-load conditions due to the line capacitance causing a charging current.
VRтАЛ=VSтАЛsec(╬▓l) тАФ receiving end voltage for a lossless long line
ICтАЛ=j╧ЙCV тАФ line charging current
Transmission lines possess shunt capacitance distributed along their length. Under light load or no-load conditions, the charging current (which flows through the line inductance) is significant compared to the load current. This leading current causes a voltage drop across the line inductance that leads to a voltage rise, resulting in the receiving end voltage (VRтАЛ) exceeding the sending end voltage (VSтАЛ).
Most prominent in long lines (typically > 250 km) due to higher shunt capacitance.
Caused by the interaction of line shunt capacitance with line series inductance.
Is a major concern during line energization under no-load.
Can be mitigated using shunt reactors at the receiving end.
None, it is a parasitic phenomenon usually requiring compensation.
Potential damage to insulation at the receiving end due to overvoltage.
Requires additional reactive power compensation (shunt reactors).
Voltage control in EHV/UHV AC transmission networks.
The effect is negligible in short and medium transmission lines because their shunt capacitance is small.
Option B and C are incorrect as loading provides a load current that offsets the charging current effect, reducing the voltage rise.
A is correct тАФ The Ferranti effect is experienced when a long transmission line is operating under light-load or no-load conditions.
Always remember: Ferranti effect is to transmission lines what shunt compensation is intended to correct; it effectively turns the line into a capacitive source.