Estimation of Impulsive Noise in an Electricity Substation

Measurements of impulsive noise in a 400/275/132-kV electricity substation are presented. The measurements are made with three antennas having overlapping bands covering the range 100 MHz-6 GHz. This range includes those bands relevant to modern wireless local area network and wireless personal area network technologies (e.g., IEEE 802.11a/b/g and IEEE 802.15.1/4), which, if proved to be sufficiently robust in the presence of impulsive noise, could play a useful role in substation monitoring and control. Impulsive events are extracted from the measured data using the wavelet packet transform, and the statistical distributions of pulse rate, pulse amplitude, pulse duration, and pulse rise time are presented. An unexpected quasi-periodic component of the noise is observed.