Impulse noise influence on communication system in high-voltage substation

In real high voltage systems, it is necessary to observe system parameters. Depend on investigated values, it is possible to detect malfunctions or overvoltage in high-voltage substation. Because of these, communication system in actual high voltage substation is implemented. In the high-voltage substation disconnector and circuit breaker are installed, whose operation causing appearance of impulse noise effect in the present communication system. Disconnector´s contacts in air-insulated substations (AIS) are moving slowly causing numerous strikes and re-strikes between contacts. Every strike causes high-frequency currents (from a few hundred kHz to a few MHz) tending to equalize potentials at the contacts. These processes are the source of impulse noise in the connected communication system. In this paper measured impulse noise level and estimate influence to probability of false alarm appearance in the communication system are presented.