A Novel Method for Calculating the Radiated Disturbance from Pantograph Arcing in High-speed Railway

Pantograph arcing is a key electromagnetic disturbance source to affect train control system in high-speed railway. Since the characteristics of pantograph arcing is related to train speed, it is necessary to investigate effective numerical modeling and measurement method. However, due to the uncontrollable train speed during on-site measurement, it is difficult to study the radiated disturbance from arcing in the corresponding speed and repeat the same measurement. Therefore, a method combined numerical modeling and reverberation chamber measurements for calculating the radiated disturbance from pantograph arcing in a high-speed railway is proposed. Numerical models of train and sensitive equipment are built to calculate the coupling coefficient in CONCEPT II. And a new measurement procedure in reverberation chamber using pulse signal as the reference source is proposed based on a speed-controllable laboratory replica to measure the total radiated power of pantograph arcing. Then the radiated disturbance from pantograph arcing to the sensitive equipment is achieved with the coupling coefficient and the total radiated power of arcing. The method is verified laboratory experiments. This method can solve the uncontrollable train speed problem during on-site measurement and improve the repeatability of measurement

Experimental Characterization of Pantograph Arcs and Transient Conducted Phenomena in DC Railways

open2An electric arc is an example of a transient event that is quite common in electrified transportation systems as by-product of the current collection mechanism. As a broadband transient, an electric arc excites a wide range of (often oscillatory) responses related to the substation and onboard filters, as well as the line resonances and anti-resonances. Similarly do the charging of onboard filter and other related inrush events. This work considers the electrical characteristics of these transients and of the excited responses in order to define their typical spectral signatures in DC railways and take them into account concerning their impact on Power Quality measurements and the measurements of instruments deployed onboard.openMariscotti, Andrea; Giordano, DomenicoMariscotti, Andrea; Giordano, Domenic

Pantograph-To-OHL Arc: Conducted Effects in DC Railway Supply System

The electrical arc occurring in the sliding contact between the supply contact line and the current collector (pantograph) of an electrical locomotive is a fast transient phenomenon able to degrade progressively the line-To-pantograph contact quality and, consequently, the continuity of operation. In order to increase the energy efficiency of the railway system, an inexpensive solution is constituted by the detection of the arc event by the analysis of voltage and current measurements already available on-board train. An essential activity to reach this objective is to set up a reliable electrical model of the railway system in which the arc events originate. To this end, this paper presents a combination of experimental and simulation analysis for the development of an electrical model of a direct current (dc) 3 kV railway system, which is aimed at better understanding the propagation of conducted effects generated by arc events. First, a laboratory experimental activity is carried out to investigate the electrical dynamic characteristics of the arc in a controlled environment. Then, a model of the dc railway system is derived and validated by using the experimental data collected in a measurement campaign on-board train. Finally, a sensitivity analysis of the main model parameters is carried out

Full Time Domain EMI Measurement system applied to Railway emissions according to IEC 62236-3-1/EN 50121-3-1 standards

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper studies the advantages of applying time-domain based instrumentation to conduct electromagnetic interference emissions from rolling-stock. In IEC 62236-3-1 or EN 50121-3-1 standards, it is mandatory to measure the railway vehicle in static and in-motion conditions. When conventional frequency sweep instrumentation is employed, difficulties regarding ambient noise variation and the short-duration of worst-case emission modes take place. In Annex B of the standard, a test procedure is described to acquire the worst-case EMI, however, as it is explained at the paper the effective measured time at each frequency is only 0.08 ms in some frequency bands. Hence, multiple movements of the vehicle are needed increasing the uncertainty of the measured source and making difficult to distinguish vehicle EMI from background noise interference. To solve this problem, a Full-TDEMI measurement system is proposed with the availability to increase the effective measured time, reduced the ambient noise variation, the usage of multiple antennas at the same time and the possibility to discard transient interference that should not be evaluated. At the end of the paper, measurements carried out with the time-domain system are shown demonstrating the effectivity of the methodology. © 2018 IEEE.Peer ReviewedPostprint (author's final draft

Electrical Characteristics of Pantograph Arcs in DC Railways: Infrastructure Influence

Electric arcs are an unavoidable by-product of current collection by sliding contact in electrified transportation systems. Electric arcs are transient phenomena with implications for PQ measurements and wearing estimation and prevention of the sliding contact and catenary. Besides being heavily influenced by mechanical characteristics and material properties, their electrical characterization encompasses spectral properties and the influence of train and traction line circuits and relative position of infrastructure elements. This paper identifies the influence of such electrical and system characteristics onto the spectral signature of electric arcs for DC railways

Analisis kualiti penulisan projek sarjana pelajar di Fakulti Pendidikan Teknikal UTHM

Isu kualiti penulisan projek saijana masih lagi di tahap yang sederhana.Tugas mengangkat tahap kesaijanaan melalui penyelidikan merupakan suatu agenda penting bagi universiti.Tujuan kajian ini dilakukan adalah untuk mengenalpasti status kesaijanaan pelajar melalui ciri-ciri kualiti penulisan pelajar saijana ke atas projek saijana yang beijaya didokumentasikan di Fakulti Pendidikan Teknikal UTHM dari tahun 2000 hingga 2006. Kajian ini melibatkan triangulasi sumber data ke atas tiga aspek iaitu pemerhatian sistematik, temubual berstruktur dan soal selidik. Sampel kajian adalah terdiri daripada pelajar semester akhir program Saijana Pendidikan Teknik dan Vokasional dan 15 orang pensyarah dipilih secara rawak yang diakui pakar dalam penyeliaan projek saijana pelajar di Fakulti Pendidikan Teknikal di Universiti Tun Hussein Onn Malaysia. Instrumen yang digunakan di dalam kajian ini adalah naskah dokumentasi projek saijana, borang soal selidik dan temubual. Analisis deskriptif dan inferensi iaitu ujian-t digunakan bagi mendapatkan analisis data yang terperinci. Dapatan kajian menunjukkan bahawa tahap penulisan projek saijana pelajar di tahap yang baik dengan kawalan dan pemerhatian penyelia dan Panel Jawatankuasa Projek Saijana pelajar di Fakulti Pendidikan Teknikal Universiti Tun Hussein Onn Malaysia. Dapatan juga menunjukkan bidang tujah yang popular di kalangan pelajar Saijana Pendidikan Teknik dan Vokasional di Fakulti Pendidikan Teknikal sepanjang tahun 2000 hingga 2006 ialah budang tujah pertama iaitu Pengajaran & Pembelajaran PTV Dalam Bidang Pengkhususan

Power Quality in Electrified Transportation Systems

"Power Quality in Electrified Transportation Systems" has covered interesting horizontal topics over diversified transportation technologies, ranging from railways to electric vehicles and ships. Although the attention is chiefly focused on typical railway issues such as harmonics, resonances and reactive power flow compensation, the integration of electric vehicles plays a significant role. The book is completed by some additional significant contributions, focusing on the interpretation of Power Quality phenomena propagation in railways using the fundamentals of electromagnetic theory and on electric ships in the light of the latest standardization efforts

How pantograph electric arcs affect energy efficiency in DC railway vehicles

In DC electrified railways pantograph electric arcs represent not only a disturbance, but the step change of the pantograph voltage affects power losses directly and indirectly. The available line voltage is reduced if the train is in traction condition, the arc itself is characterized by ohmic power losses, and the triggered oscillating transient responses are characterized by a net power loss. In addition, if arc occurs during braking the arc voltage suddenly increases the pantograph voltage and may interfere with the dissipative braking chopper, reducing the recovered energy. This work presents the model and analysis of these phenomena with experimental results for arcs measured on a 3 kV dc line in traction and braking conditions

APD outdoors time-domain measurements for impulsive noise characterization

A novel measurement and post-processing technique for estimating if impulsive noise is capable of degrading the performance of digital communication systems (DCS) is presented. It is based on the well-known capability of the amplitude probability distribution (APD) to estimate the bit-error-rate of digital communication system in the presence of electromagnetic interferences. However, the APD shall be computed from measurements taken in the absence of the useful signal of the communication system, which is a strong handicap for in-situ measurements. The main contribution of the work presented is the combination of time domain EMI measurements and decomposition techniques for separating the impulsive noise from the narrow band signals of the digital communication systems. Therefore, although the communication system signal is present at the test site, the APD diagram is obtained without the influence of the communication system, which is crucial to directly relate the shape of the diagram with the bit-error-rate introduced by the impulsive noise. This is an important step forward compared with the traditional approach as it offers the possibility to study the impact of impulsive interferences although DCS, such as broadcasting services, are present at interference scenarios.Postprint (published version