Corona positive and negative effect on high voltage technology ( engineering) - Research Paper Example

The process by which a current flows into a neutral fluid (air) from an electrode with high potential, by ionizing the fluid in order to create a plasma region around the electrode, is known as corona discharge. Charge is then passed to the nearby areas of lower potential by the ions, or the ions may recombine and form neutral gas molecules. A large enough potential gradients at a point cause the fluid at that point to be ionized and become conductive. A charged object with a sharp point causes the electric field strength around the point to be much higher than elsewhere.

When the air around this point becomes conductive, it increases the apparent size of the conductor, making the new conductive region less sharp. This makes the ionization region not able to extend past this local region. Outside the region of conductivity and ionization, the charged particles will find their way to an opposite charged object where they will be neutralized. During the formation of corona, the air around the conductor becomes conductive. This leads to a virtual increase in the effective diameter of the conductor.

Due to the increased diameter, the electro-static stresses reduce between the conductors. This reduces the maximum voltage gradient between the conductors. Coronas can be used to eliminate particulate matter from the air streams. The air is first charged, the charged stream is passed through a comb of alternating polarity. This is done to deposit the charged particles onto the oppositely charged plates Corona is able to generate sound energy during its activity. This audible noise can be able to increase during foul weather conditions especially with a lot of rain.

Rainwater drops may collect at the surface of the conductors thereby increasing the corona activity, which will make the humming, or crackling sound to be heard especially near transmission lines. Corona is also responsible for causing radio frequency noise especially near transmission lines.