Longitudinal Propagation Characteristic of Pantograph Arcing Electromagnetic Emission With High-Speed Train Passing the Articulated Neutral Section

Critical Review of EMC Standards for the Measurement of Radiated Electromagnetic Emissions from Transit Line and Rolling Stock

“…Early announcement of train arrival at the measurement site with its emissions well visible when the train is still far away. This is quantitatively shown in [43], Figure 10, where the calculated H-field at 30 m from track attenuates less than 10 dB in the first 2000 m up to about 0.5 MHz, and then more than 20 dB at 1 MHz and above.…”

“…The vehicle cannot be considered a point source, as sketched below in Figure 4 (see the source points S 1 , S 2 , and S 3 ) and if we observe that wavelength and distance are both comparable with its dimensions [47]. The catenary should also be considered as an effective radiation means, further extending the physical size of the source (see [43] for an estimate of the effective length of the radiating catenary at various frequencies in the MHz range, which approximately ranges in the hundreds meters). As result, while the vehicle passes in the measurement area, significant variations of the measured intensity may occur.…”

“…Stipulation of limits is a complex process that should consider the victim radio services and the radiation efficiency of the emitting elements, i.e., vehicle body, electric arc, and pantograph, but most of all the catenary system. The latter can be modeled and behaves like a long wire antenna [43], fairly efficient over the MF and HF range (Medium Frequency and High Frequency as in ITU-T definition, between 0.3 and 30 MHz), where various services operate (radiolocation, maritime mobile, radio navigation, amateur radio, and broadcasting) [44]. Third rail systems have lower radiation efficiency for two reasons: the height of the third rail above top of rail (and thus the emitting loop area) is less than 1/10 of that for catenary systems; the coupling capacitance to the running rails and ground, as a consequence, is larger.…”

“…A traction line in resonant conditions has some peculiar behavior for what concerns electromagnetic emissions (see e.g., [38,43] for two related mathematical formulations):…”

“…Capacitance c may be in principle determined with great accuracy [45,58], but is affected by elements other than line conductors (connected cables and transformers, adjacent lines, and rolling stock enclosure). Losses due to skin effect [43,61] and damping provided by connected elements should be added to the pure ohmic value of r, derived from cross section and conductivity information. In general, emissions peaks and line resonances may be observed with different frequency width.…”