Radio Interference and Effect on Line Performance

Radio Interference and Effect on Line Performance

The corona discharge produces the radiations which may introduce noise signals in the communication lines, carrier signal, radio and television receivers, navigation signals etc. Such noise signals which adversely affect the wireless signals, produced by corona is called radio interference.

The radio interference can cause problems to communication lines which are few kilometres away from corona. The radio interference is significant for the voltage levels greater than 200 kV.

The radio interference is measured interms of an electric field in microvolt per metre at any distance from the transmission line. The radio interference field is inversely proportional to the radio frequency hence the transmission like radar, television, FM broadcasting etc. are less affected by the radio interference.

The radio interference increases gradually till the system voltage produces measurable corona loss. After this voltage level, radio interference increases rapidly and becomes very high. The rate of increase in radio interference depends on the nature of the conductor surface and the diameter of the conductors. For a smooth surface conductors, in good weather conditions, the radio interference is small. While designing the transmission line, the radio interference plays an important role.

Review Question

1. Explain the practical importance of corona.