Uncertainty of the Energy Measurement Function deriving from Distortion Power Terms for a 16.7 Hz Railway

Abstract

<p class="Abstract">In electrified railways, harmonic active power terms can be significant in the order of the uncertainty required by the EN 50463-2 standard for power and energy measurements in railways. Nonactive power terms (encompassing reactive and distortion harmonic terms) are much more significant than the sole fundamental reactive power. This work considers the implementation of the EN 50463-2 energy measurement function, including the criteria for the significance of the measured and calculated terms, and it carries out a Monte Carlo analysis to assess the impact of harmonic power terms on the measured energy and its uncertainty.</p>

Experimental characterisation of active and non‐active harmonic power flow of AC rolling stock and interaction with the supply network

“…The most direct application is to metering and accounting of consumed and utilised energy, defining first the minimum frequency range of energy metres to include relevant distortion power terms and also supporting fair billing, by distinguishing power terms of internal and external origin. It was in fact demonstrated [4, 14] that harmonic active power is relevant to the calculation of the total energy consumption in particular compared to the uncertainty target. Similarly, such methods may be used to assess the distortion provided by the network attempting to quantify its spectral P and Q , rather than V and I components separately.…”

“…Rolling stock harmonic emissions are assessed and analysed for a variety of purposes: first of all prevention of interference to signalling, directly conducted or by induction [11,12], and more recently for assessment of power and energy consumption [3][4][5]13] [14], all carried out in a single-train perspective. Thus information on network and its quantities is limited to what can be measured at the line-pantograph interface.…”

Real-time power quality measurement audit of government building – A case study in compliance with IEEE 1159

“…There are specific standards that are followed to maintain equipment and personnel safety, and it depends on the country and the industry [8]- [9]. Some associations accountable for emergent PQ standards comprise the Institute of Electrical and Electronics Engineers (IEEE), the International Electronic Commission (IEC), National Electrical Manufacturers Association (NEMA), National Fire Protection Association (NFPA), National Environmental Policy Act (NEPA), and American National Standards Institute (ANSI), etc., [10]. The true value of any PQ monitoring program lies in its ability to analyse and interpret voluminous raw data and generate actionable information to prevent PQ problems or improve the overall power quality performance.…”

Metrology and Measurement Systems

“…A new perspective is considering their effect in terms of power flow, its measurement and billing. Besides the fundamental (16.7 Hz, 50 Hz, 60 Hz), also harmonics may be relevant for the active and reactive power exchange [2][3][4][5]. With the introduction of energy metering on-board [6,7], a definition is necessary of active and reactive power concepts that is valid for the fundamental and harmonics, which should be taken into account to satisfy the requirements of accuracy and uncertainty [7].…”

“…-accurate measurement and evaluation of harmonic power components to be included in the determination of the so-called Energy Measurement Function (EMF), discussed in [2][3][4][5], assessing the relevance of harmonic power components and the impact on EMF uncertainty; -identification of harmonic power sources with suitable indicators, able to clearly represent the amount of distortion and to determine if some train is an active source pulling power at some harmonics or just a passive load for the line voltage distortion caused by other trains or substations [12], including possible forms of cost sharing and billing [13]; other methods based on interpretation of spectra and waveforms are shown in [14]. An interesting discussion of the effect of distortion on the operation of energy meters can be found in [15][16][17][18].…”