Because of the high value of traveling voltage in the TX lines theair around it actually ionizes and cause the current to flow in the surrounding and because of that ionization ozone gas is produced
Due to corona effect virtually conductor size is increase and therefor resistance in transmission line is decreases.so I2R losses will decreases...
A: Transmission lines while there is ceramic insulators providing separation to the phases will have a corona if the insulators are dirty providing small current leakage ionizing the air around it therefore corona effect.
for sake of safety and protection the high voltage transmission lines are erected in less populated areas ie. villages , these lines have operating voltages about 220kv , 440kv , 132 kv( high tension lines) . while in cities the voltage is distributed at low voltages ( about 11kv(industry) , 440v residential ) because of safety issue . since corona loss highly depends on the operating voltage of lines thats why it is mostly seen in villages.
The virtual diameter of the conductor becomes greater to carry more current
That transmission is all computer controlled. No vacuum lines on it.
The corona effect is less pronounced in High Voltage Direct Current (HVDC) lines primarily due to their design features and operating characteristics. HVDC systems typically operate at higher voltages and lower frequencies compared to AC systems, resulting in lower electric field gradients around the conductors. Additionally, HVDC lines often utilize larger conductor diameters and specific geometries that help reduce surface irregularities, minimizing the likelihood of corona discharge. As a result, HVDC lines experience reduced energy losses and improved efficiency in transmission over long distances.
there are some distortion in transmission line : copper loss,dielectric loss,skin effect
1. by increasing conductor size. 2. by increasing conductor spacing.
Bundled conductors are used to reduce the effect of corona. As in place of a single conductor. two conductors are used in parallel the voltage gradient build up is less and thus the ionisation of the surrounding air is decreased. Therefore the effect of corona is reduced.
Bcoz, corona effect is only possible in high voltage AC supply due to the frequency. That is, the frequency and the HT voltage causes the arc b/w 2 conductors.so , here the air is act as the arc transmitting medium.we called it as Corona. It is highly impossible in DC bcoz of no frequency.
Heat is generated due to resistive losses when a current flows. Noise is either from vibration or corona effect in case of high voltage lines
Corona is a pale blue discharge caused by an intense electric field breaking down the insulating properties of air. It normally occurs at sharp corners or points on energised high-voltage conductors, where the electric field is particularly intense. It can also occur at the surface of single, narrow, conductors -which is why very high-voltage transmission line conductors are bundled in groups of two (e.g. 275-kV lines in the UK) or more (e.g. four in the case of 400-kV lines in the UK).So a corona is caused by voltage (electric fields) , whether a load current (magnetic fields) is flowing or not. So a load is not neccessary for corona discharge to occur.