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The current drawn by the line owing to corona loss is
Non-sinusoidal
Sinusoidal
DC
Square
Non-sinusoidal
Corona discharge is a non-linear phenomenon that occurs when the electric field strength exceeds the dielectric strength of air. Because the ionization process depends non-linearly on the instantaneous applied voltage, the resulting corona current waveform is non-sinusoidal, even if the applied voltage is purely sinusoidal.
Corona discharge is a non-linear phenomenon that occurs when the electric field strength exceeds the dielectric strength of air. Because the ionization process depends non-linearly on the instantaneous applied voltage, the resulting corona current waveform is non-sinusoidal, even if the applied voltage is purely sinusoidal.
PcтАЛ=╬┤241тАЛ(f+25)DrтАЛтАЛ(VтИТVcтАЛ)2├Ч10тИТ5 тАФ Peek's law for power loss due to corona (kW/phase/km)
VcтАЛ=m0тАЛg0тАЛ╬┤rln(rDтАЛ) тАФ Critical disruptive voltage calculation
As the applied AC voltage rises above the critical disruptive voltage, air molecules near the conductor surface become ionized. This ionization is confined to the peaks of the voltage wave, creating a sudden flow of charge during these intervals. Consequently, the current waveform exhibits pulses or harmonics rather than a smooth sine wave, resulting in a non-sinusoidal current signal.
Corona occurs only when the voltage gradient exceeds the breakdown strength of air (approx 30 kV/cm peak).
Non-sinusoidal current leads to the generation of harmonics in the power system.
Corona results in power loss, radio interference, and audible noise.
The wave shape of the corona current is distorted due to the non-linear relationship between voltage and current during the ionization cycle.
Power loss in transmission lines
Generation of electromagnetic interference (EMI) and radio interference
Chemical corrosion due to Ozone (O3тАЛ) formation
High Voltage Transmission Line Engineering
Insulation Coordination studies
Corona is more significant in AC systems than in DC systems due to the cyclic ionization and deionization.
Option B (Sinusoidal) is incorrect because the ionization process is restricted to voltage peaks, distorting the waveform.
Option D (Square) implies a switching behavior not present in atmospheric corona discharge.
A is correct тАФ The ionization process depends non-linearly on the applied voltage, causing the drawn current to be non-sinusoidal.
Always remember that any non-linear electrical discharge phenomenon (like corona or arc) inherently introduces harmonics into the system, making the current waveform non-sinusoidal.