Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Shunt compensation for long EHV lines is primarily resorted to
Improve voltage profile
Improve stability
Reduce fault currents
All of above
Improve voltage profile
Shunt compensation in Extra High Voltage (EHV) lines is primarily used to control the voltage profile along the transmission line. Long lines exhibit the Ferranti effect under light load conditions, where the receiving end voltage exceeds the sending end voltage due to line charging capacitance; shunt reactors are used to counteract this.
Shunt compensation in Extra High Voltage (EHV) lines is primarily used to control the voltage profile along the transmission line. Long lines exhibit the Ferranti effect under light load conditions, where the receiving end voltage exceeds the sending end voltage due to line charging capacitance; shunt reactors are used to counteract this.
VrтАЛ=VsтАЛтЛЕcos(╬▓l) тАФ Receiving end voltage of a lossless line at no load
QcтАЛ=V2тЛЕ╧ЙC тАФ Reactive power generated by line capacitance
The line capacitance in long EHV lines draws a capacitive charging current. Under light load or no-load conditions, this current flow through the line inductance creates a voltage rise at the receiving end (Ferranti effect). Shunt reactors (inductors) provide inductive compensation to neutralize this leading reactive power, thereby maintaining the voltage within limits.
Long transmission lines (>250 km) have significant shunt capacitance.
Ferranti effect causes receiving end voltage to rise at low loads.
Shunt reactors are typically installed at line ends or at intermediate substations.
Shunt compensation helps in keeping the voltage profile flat.
Prevents overvoltage during light load conditions
Reduces the requirement of high-voltage insulation at the receiving end
Reduces transmission capacity during peak load periods if not switched off
Increases losses due to circulating currents
EHV and UHV transmission lines
Long-distance power corridors
Shunt capacitors are used for lagging power factor correction (load side), whereas shunt reactors are used for leading power factor correction (line side).
Option B (Stability) is primarily achieved via Series Compensation, which reduces the effective line reactance (X).
A is correct тАФ Shunt compensation is primarily utilized to maintain a stable voltage profile by mitigating the Ferranti effect in long EHV transmission lines.
Always remember: Shunt compensation (Reactors) = Voltage Control; Series compensation (Capacitors) = Power Transfer Capability/Stability.