Man-made radio noise

The design of robust receivers in environments with strong impulsive noise may be challenging due to their high-amplitude events and their rare but nonnegligible occurrence. In substation environments, these impulsive noises are predominant. They are induced by corona discharges such as electrical arcs or partial discharges in the air. The emitted radiations can occupy a wide range of frequencies typically reaching a few gigahertz with very high amplitude. In this paper, we develop a generalized model of impulsive electromagnetic interference induced by corona discharges for wireless channels. Radiations emitted by these sources are generally transient impulses, their occurrences follow cyclostationary process, due to their generation by an alternative current. In this model, we both take into account the physical mechanism of these discharges and the induced electromagnetic radiations. Experimental results validate the approach in terms of first- and second-order statistics such as amplitudes, interarrival time, occurrences, and power spectrum densities of impulsive transient noise.

A Model of Electromagnetic Interferences Induced by Corona Discharges for Wireless Channels in Substation Environments

In last chapters, an overview of electromagnetic interference induced by partial discharges and their impact on wireless communication systems has been discussed. Measurement campaigns in substations have been conducted. These sources can take place in high-voltage equipment like transformers, powerlines, bushing bars, etc.

A Physical Model of EMI Induced by a Partial Discharge Source

Electromagnetic disturbance from power lines is one of the main sources of man-made noise affecting communications in the high-frequency radio band. Most radio disturbances generated by power lines are of two types: gap-type noise caused by electric discharges across line hardware, and corona noise caused by the partial breakdown of the air due to the high electric fields around transmission-line conductors. While the physical mechanisms of these noise types have been investigated in detail, these studies have not yet been used to develop noise models for the evaluation of communication-system performance. This paper presents a mathematical model that allows the fundamental mechanisms of gap-type noise to be simulated. With this model, the effect of gap-type noise processes on various high-frequency communication systems can be determined by direct computation as well as by experimental observation. The mathematical model was used to derive an expression for the demodulated power spectral density (PSD) compared with field observations.

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Paul H. Moose

Papers

A Model for Inpulsive Power-Line Radio Disturbance Due to Gap-Type Discharges