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

Abstract

Accurate and comprehensive methods for the assessment of radiated electromagnetic emissions in modern electric transportation systems are a necessity. The characteristics and susceptibility of modern victim signaling and communication radio services, operating within and outside the right-of-way, require an update of the measurement methods integrating or replacing the swept frequency technique with time domain approaches. Applicable standards are the EN 50121 (equivalent to the IEC 62236) and Urban Mass Transport Association (UMTA) with additional specifications from project contracts. This work discusses the standardized methods and settings, and the representative operating conditions, highlighting areas where improvements are possible and opportune (statistical characterization of measurement results, identification and distinction of emissions and line resonances, and narrowband and broadband phenomena). In particular for the Electromagnetic Compatibility (EMC) assessment with new Digital Communication Systems, the characterization of time distribution of spectral properties is discussed, e.g., by means of Amplitude Probability Distribution and including time distribution information. The problem of determination of site and setup uncertainty and repeatability is also discussed, observing on one hand the lack of clear indications in standards and, on the other hand, the non-ideality and intrinsic variability of measurement conditions (e.g., rolling stock operating conditions, synchronization issues, and electric arc intermittence).

The Effects of Supraharmonic Distortion in MV and LV AC Grids

“…Such detectors may be an rms detector, a peak detector, or a quasi-peak detector, the latter causing some concern. Its use is supported by CISPR and generally by RF EMC standards as an emissions weighting for a hypothetical jamming of analog radio transmissions for broadcasting purposes (no longer so widely used in the modern world of digital communication);its output being dependent on the time distribution of the spectral characteristics of the incoming signal, it can hardly be compared to a simpler rms or peak detector, as commented in [ 78 ] for impulsive emissions originating from pantograph electric arcs. Nonetheless, its application is still mandatory and has recently attracted a lot of effort to devise an efficient time-domain implementation [ 79 , 80 ].…”

Estimation of Number of Cores for Preventing Common-Mode Inductor Saturation in Railway Traction Inverters

“…Since the applied CM voltage of the inductor corresponds to (2), the magnetic flux Φ inside the inductor corresponds to (3).…”

“…In traction inverters for rolling stock, the reduction of electromagnetic interference (EMI) is particular importance [1], [2], [3], [4], [5]. Various measures are required to comply with the limitations of international standards such as IEC 62236 series (European standards are EN 50121 series) and requirements such as EN 50238 series for electromagnetic radiation from different railway signaling systems [6], [7].…”

Review of models and measurement methods for compliance of electromagnetic emissions of electric machines and drives

“…With a parallel to other systems featuring large apparatus, relevant factors with impact on uncertainty and reproducibility are: i) emissions from a long cable line connected to the motor or generator, that can be borrowed from the scenario of the catenary feeding line in electrified railways [94]; ii) moving source in case of vehicles and electrified transports, as well as moving industrial apparatus (e.g. for positioning or tooling); iii) variability of operating conditions for large machines that cannot be bench tested under satisfactory conditions.…”