Measurement procedures and uncertainty evaluation for electromagnetic radiated emissions from large-power electrical machinery

Methods of measurement and data analysis are considered for the electromagnetic (EM) emissions from large-power rotating machinery (in this paper, a synchronous generator is considered as a working example). The data recorded during two measurement campaigns are used to prove the analysis methods and to better describe the measurement procedures. The following important factors are considered: 1) the reactive behavior of the field, site attenuation, and antenna factor determination; 2) the physical dimensions of the source of the emissions and its impact on the correction factor uncertainty; 3) the EM environment; and 4) the ambient EM noise. These are practical factors (including safety distances, reproducible test conditions, etc.) that limit the choice of the measuring position and distance and determine measurement accuracy.