Correct option is B
(a) No skin effect: This is correct. HVDC transmission does not experience the skin effect, which is a phenomenon where alternating current (AC) tends to flow near the surface of a conductor at higher frequencies, causing increased resistance.
(b) High corona loss: This is incorrect. HVDC transmission generally has lower corona losses compared to HVAC (High Voltage Alternating Current) transmission. Corona loss is the loss of power due to ionization of the air surrounding the conductors, and it is typically more pronounced in AC systems because of the alternating nature of the voltage.
(c) Higher operating voltage: This is correct. HVDC systems often operate at higher voltages compared to AC systems, which helps in reducing the current and thereby minimizing losses over long distances.
(d) Good voltage regulation: This is correct. HVDC systems have good voltage regulation capabilities because they are less affected by impedance and reactive power issues, making them efficient for long-distance transmission.
Therefore, the incorrect statement is: (b) High corona loss
