Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.5
3.2
Journals
Energies
Special Issues
Power Quality in Electrified Transportation Systems
energies-logo
Submit to Energies Review for Energies Propose a Special Issue

Journal Menu

► Journal Menu

Journal Browser

► Journal Browser
share announcement

Power Quality in Electrified Transportation Systems

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "A1: Smart Grids and Microgrids".

Deadline for manuscript submissions: closed (25 July 2021) | Viewed by 43854

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Prof. Dr. Andrea Mariscotti

E-Mail Website
Guest Editor
DITEN, University of Genova, 16145 Genova, Italy
Interests: EMC applied to industrial, military, and transportation systems; power quality and interference; power system modeling and analysis; electrical measurements, design, and construction of measurement setups and instrumentation; earthing, stray current, and lightning protection design
Special Issues, Collections and Topics in MDPI journals
Dr. Leonardo Sandrolini

E-Mail Website
Guest Editor
Department of Electrical, Electronic and Information Engineering, University of Bologna, 40136 Bologna, Italy
Interests: electromagnetic compatibility
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Electrified transportation systems (from railways to metros, tramways, and other newer guideway systems) feature a variety of current distribution and collection systems, as well as an increasing use of power electronic conversion to support higher dynamics, better driving performance, and more efficient energy exploitation.

Static power conversion has known side effects caused by internal switching and transformation process: waveform distortion, harmonics and interharmonics, significant and varied reactive and nonactive power terms. The system architecture has grown in complexity, including solutions for energy storage and bidirectional exchange of energy with the utility, and an increased number of interacting control systems.

Standards and regulations for industrial applications extensively cover a variety of power quality phenomena and events, both steady-state and transient. The extension of standardization advancement to electric transports is not rapid and immediate for various reasons: among others, the peculiar current collection mechanism and the mechanical interface with the vehicles, the highly dynamic behavior of connected loads, and the interference mechanisms to signaling and communication systems (relevant to safety and availability).

A complex work is being developed in terms of analysis of network and load response (e.g., resonance and instability), interface and mutual influence with transmission and distribution at higher voltage, characterization of rolling stock as regards distortion patterns and input admittance (including analysis of nonlinearity and control), and methods and strategies to improve and compensate for power quality. The attainment of the investigations is particularly important since the bandwidth of onboard converters has increased, thus requiring a more cautious and comprehensive approach, but ensuring wider margins of control and optimization.

It would be beneficial to revisit the consolidated concepts of power quality in light of the new findings and research directions, to serve their purpose of quantifying the real impact in terms of distortion, instability, induction, losses, and aging of components of an electrified railway and of its vehicles.

This Special Issue has the aim of collecting contributions for this complex scenario, improving techniques of analysis, including modern converter architectures, fostering the definition of suitable power quality indices, and exploring suitable measurement methods and systems, with a constructive and open comparison of proposals, solutions, and experiences.

Original contributions including experimental results are expected. The topics of interest include but are not limited to:

  • Analysis and modeling of harmonic emissions of rolling stock and converters, and interaction with the supply traction network;
  • Characterization of novel traction supply architectures and power conversion apparatuses for Power Quality improvement, including solutions for power quality compensation;
  • Definition and study of suitable power quality indices for electrified transports, covering not only more traditional phenomena, but also network instability, induction and interference with signaling and communication;
  • Measurement methods and instrumentation, including realization of embedded systems and applications suitable for onboard and substation environment;
  • Algorithms for data and signal analysis, such as spectral and statistical analysis, as well as correlation with operating conditions, network characteristics, and infrastructure.

Prof. Dr. Andrea Mariscotti
Prof. Dr. Leonardo Sandrolini
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Power quality
  • Electrified railways
  • Rapid transit system
  • High-speed railways
  • Train–network interaction
  • Power converter
  • Harmonic instability
  • Harmonic resonance
  • Network oscillation
  • Spectrum analysis
  • Harmonic analysis
  • Measurement of electric quantities
  • Voltage and current transducers

Published Papers (16 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

17 pages, 6832 KiB  
Article
Complex Design Method of Filtration Station Considering Harmonic Components
by Vaclav Kus, Bohumil Skala and Pavel Drabek
Energies 2021, 14(18), 5872; https://doi.org/10.3390/en14185872 - 16 Sep 2021
Cited by 1 | Viewed by 1223
Abstract
The paper deals with a new methodology for calculating the filter parameters. The basis is respect for the fact that the real filter current consists of other harmonic components, which filter is tuned. The proposed methodology was used to design filters for traction [...] Read more.
The paper deals with a new methodology for calculating the filter parameters. The basis is respect for the fact that the real filter current consists of other harmonic components, which filter is tuned. The proposed methodology was used to design filters for traction substation 25 kV/50 Hz. The operation of the locomotives in the AC supply systems of 25 kV/50 Hz leads to a rising of higher order harmonic currents. Due to the 1-phase supply system, these are mainly the 3rd and 5th harmonics. By simulation and subsequent measurement of the proposed traction power station filters the proposed methodology was verified. Thus, the filter design can also be used for filter compensating stations of the standard 3-phase distribution network. The described method presents an optimal filter design without unnecessary oversizing. This fact reduces the size and cost of the filter. It is shown that it is possible to design a filter that meets the requirements for power quality under extreme load and to minimise distortion of line voltage. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

22 pages, 5001 KiB  
Article
Detection of Harmonic Overvoltage and Resonance in AC Railways Using Measured Pantograph Electrical Quantities
by Andrea Mariscotti and Leonardo Sandrolini
Energies 2021, 14(18), 5645; https://doi.org/10.3390/en14185645 - 08 Sep 2021
Cited by 17 | Viewed by 2054
Abstract
Harmonic resonances are part of the power quality (PQ) problems of electrified railways and have serious consequences for the continuity of service and integrity of components in terms of overvoltage stress. The interaction between traction power stations (TPSs) and trains that causes line [...] Read more.
Harmonic resonances are part of the power quality (PQ) problems of electrified railways and have serious consequences for the continuity of service and integrity of components in terms of overvoltage stress. The interaction between traction power stations (TPSs) and trains that causes line resonances is briefly reviewed, showing the dependence on infrastructure conditions. The objective is monitoring of resonance conditions at the onboard pantograph interface, which is new with respect to the approaches proposed in the literature and is equally applicable to TPS terminals. Voltage and current spectra, and derived impedance and power spectra, are analyzed, proposing a compact and efficient method based on short-time Fourier transform that is suitable for real-time implementation, possibly with the hardware available onboard for energy metering and harmonic interference monitoring. The methods are tested by sweeping long recordings taken at some European railways, covering cases of longer and shorter supply sections, with a range of resonance frequencies of about one decade. They give insight into the spectral behavior of resonances, their dependency on position and change over time, and the criteria needed to recognize genuine infrastructure resonances from rolling stock emissions. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

19 pages, 2278 KiB  
Article
The Problem of Train Scheduling in the Context of the Load on the Power Supply Infrastructure. A Case Study
by Szymon Haładyn
Energies 2021, 14(16), 4781; https://doi.org/10.3390/en14164781 - 06 Aug 2021
Cited by 7 | Viewed by 1786
Abstract
This article deals with the new challenges facing modernising railways in Poland. We look at the problem of the efficiency of the power supply system (3 kV DC) used in the context of the increasing use of electric vehicles, which have a higher [...] Read more.
This article deals with the new challenges facing modernising railways in Poland. We look at the problem of the efficiency of the power supply system (3 kV DC) used in the context of the increasing use of electric vehicles, which have a higher demand for electricity than the old type. We present and characterise the power supply system in use, pointing out its weaknesses. We consider a case study. The load of the power supply network generated by the rolling stock used in Poland was examined using a microsimulation. A real train timetable was taken into account on a fragment of one of the most important railway line sections in one of the urban agglomerations. Then the results were compared with the results of a microsimulation in which old units were replaced by new trains. These tests were carried out in several variants. We found critical points in the scheduling of railway system use. Our results indicate that it is becoming increasingly necessary to take into account the permissible load capacity of the supply network in certain traffic situations in the process of timetable construction. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

19 pages, 2010 KiB  
Article
Electrodynamics of Reactive Power in the Space of Inter-Substation Zones of AC Electrified Railway Line
by Mykola Kostin, Anatolii Nikitenko, Tetiana Mishchenko and Lyudmila Shumikhina
Energies 2021, 14(12), 3510; https://doi.org/10.3390/en14123510 - 13 Jun 2021
Cited by 4 | Viewed by 2023
Abstract
In railway traction, the definition of “electromagnetic field” is functionally connected to the concept of the reactive power consumed by the electric rolling stock, and characterized by the running and standing electromagnetic waves in the space of the inter-substation zones from the site [...] Read more.
In railway traction, the definition of “electromagnetic field” is functionally connected to the concept of the reactive power consumed by the electric rolling stock, and characterized by the running and standing electromagnetic waves in the space of the inter-substation zones from the site of the AC traction system. Such a definition is established and theoretically justified by the theory of electromagnetic fields. This article uses the methodology of this theory, in particular, a method for power balance estimation in electromagnetic fields based on Maxwell’s equations, as well as methods for the analysis of running and standing electromagnetic waves based on the theory of reflection, propagation and transmission of plane harmonic waves. The research considers the regularities of standing electromagnetic waves in the space of inter-substation zones of electric traction systems, which occur due to the incomplete reflection of incident waves from the contact wire and metal parts of the roof surface and the frontal part of the body of the electric rolling stock. The flow of electricity to the roof surface and the frontal part of the body of an electric locomotive is considered. The possibility of using existing methods to reduce wave reflections and thereby to effectively compensate for reactive power in the space of inter-substation zones is discussed. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

21 pages, 2294 KiB  
Article
Review of Legal Aspects of Electrical Power Quality in Ship Systems in the Wake of the Novelisation and Implementation of IACS Rules and Requirement
by Janusz Mindykowski, Tomasz Tarasiuk and Piotr Gnaciński
Energies 2021, 14(11), 3151; https://doi.org/10.3390/en14113151 - 28 May 2021
Cited by 6 | Viewed by 2389
Abstract
This paper deals with new challenges regarding power quality in ship technology resulting from the novelisation and implementation of IACS (International Association of Classification Societies) rules and requirements. These rules, known as IACS E24 2016/2018, address harmonic distortion for ship electrical distribution systems, [...] Read more.
This paper deals with new challenges regarding power quality in ship technology resulting from the novelisation and implementation of IACS (International Association of Classification Societies) rules and requirements. These rules, known as IACS E24 2016/2018, address harmonic distortion for ship electrical distribution systems, including harmonic filters. The reasons for the legislative changes based on a short overview of power quality-related accidents are discussed, after which a brief presentation of the updated IACS rules illustrated by a related DNV GL (Det Norske Veritas Germanischer Lloyd) case study is shown. A key part of this paper includes proposals concerning harmonics and interharmonics, distortion indices and transient disturbances. The aim of these proposals is to unify power quality indices and measurement procedures to maintain effective and comparable criteria for monitoring distortion and establish requirements for ship owners, designers, shipbuilders, classifiers, and crew members of marine objects. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

16 pages, 6738 KiB  
Article
Harmonic Mitigation in Electric Railway Systems Using Improved Model Predictive Control
by Chakrit Panpean, Kongpol Areerak, Phonsit Santiprapan, Kongpan Areerak and Seang Shen Yeoh
Energies 2021, 14(7), 2012; https://doi.org/10.3390/en14072012 - 05 Apr 2021
Cited by 6 | Viewed by 2717
Abstract
An electric multiple unit (EMU) high-speed train is the dynamic load that degrades the power quality in an electric railway system. Therefore, a power quality improvement system using an active power filter (APF) must be considered. Due to the oscillating load current in [...] Read more.
An electric multiple unit (EMU) high-speed train is the dynamic load that degrades the power quality in an electric railway system. Therefore, a power quality improvement system using an active power filter (APF) must be considered. Due to the oscillating load current in the dynamic load condition, a fast and accurate harmonic current-tracking performance is required. As such, this paper proposes the design of a model predictive control (MPC) since the minimization of cost function in the MPC process can suitably determine APF switching states. The design technique of MPC is based on the APF mathematical model. This controller was designed to compensate the time delay in the digital control. Moreover, the synchronous detection (SD) method applied the reference current calculations, as shown in this paper. To verify the proposed MPC, the overall control of APF was implemented on a eZdsp F28335 board by using the hardware-in-the-loop technique. The testing results indicated that the proposed MPC can provide a fast and accurate harmonic current-tracking response compared with the proportional-integral controller. In the load changing condition, the MPC was still effective in providing a good result after compensation. The percentage of total harmonic distortion, the percentage current unbalance factor, and the power factor would also be kept within the IEEE Standard 519 and IEEE Standard 1459. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

21 pages, 10215 KiB  
Article
A Novel Co-Phase Power Supply System for Electrified Railway Based on V Type Connection Traction Transformer
by Shaofeng Xie, Yiming Zhang and Hui Wang
Energies 2021, 14(4), 1214; https://doi.org/10.3390/en14041214 - 23 Feb 2021
Cited by 8 | Viewed by 3056
Abstract
Power quality and neutral section are two technical problems that hinder the development of electrified railway to high-speed and heavy railway. The co-phase power supply technology is one of the best ways to solve these two technical problems. At present, a V type [...] Read more.
Power quality and neutral section are two technical problems that hinder the development of electrified railway to high-speed and heavy railway. The co-phase power supply technology is one of the best ways to solve these two technical problems. At present, a V type connection traction transformer is widely used in a power frequency single-phase AC traction power supply system, especially in high-speed railway. In this paper, a new type of co-phase power supply system for electrified railway based on V type connection traction transformer is proposed. One single-phase winding in the V type connection traction transformer is used as main power supply channel, and three ports are used as compensation ports. Neutral section is no longer set with traction substation, and the train is continuously powered through. The independent single-phase Static Var Generators (SVGs) are used to compensate the three-phase imbalance caused by single-phase traction load. When necessary, the power factor can be improved at the same time. The principle, structure, control strategy, and capacity configuration of the technical scheme are analyzed in this paper, and the effectiveness of the scheme is verified by using the measured data of electrified railway. The advantage of this scheme lies in the universal applicability of the V type connection traction transformer, and the flexibility of the SVG device. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Graphical abstract

27 pages, 24850 KiB  
Article
Experimental Validation of a Reduced-Scale Rail Power Conditioner Based on Modular Multilevel Converter for AC Railway Power Grids
by Mohamed Tanta, Jose Cunha, Luis A. M. Barros, Vitor Monteiro, José Gabriel Oliveira Pinto, Antonio P. Martins and Joao L. Afonso
Energies 2021, 14(2), 484; https://doi.org/10.3390/en14020484 - 18 Jan 2021
Cited by 13 | Viewed by 2533
Abstract
Rail power conditioner (RPC) has the ability to improve the power quality in AC railway power grids. This power conditioner can increase the loading capacity of traction substations, balance the active power between the feeder load sections, and compensate for reactive power and [...] Read more.
Rail power conditioner (RPC) has the ability to improve the power quality in AC railway power grids. This power conditioner can increase the loading capacity of traction substations, balance the active power between the feeder load sections, and compensate for reactive power and current harmonics. At present, there is increasing use of multilevel converter topologies, which provide scalability and robust performance under different conditions. In this framework, modular multilevel converter (MMC) is emerging as a prominent solution for medium-voltage applications. Serving that purpose, this paper focuses on the implementation, testing, and validation of a reduced-scale laboratory prototype of a proposed RPC based on an MMC. The developed laboratory prototype, designed to be compact, reliable, and adaptable to multipurpose applications, is presented, highlighting the main control and power circuit boards of the MMC. In addition, MMC parameter design of the filter inductor and submodule capacitor is also explained. Experimental analysis and validation of a reduced-scale prototype RPC based on MMC topology, are provided to verify the power quality improvement in electrified railway power grids. Thus, two experimental case studies are presented: (1) when both of the load sections are unequally loaded; (2) when only one load section is loaded. Experimental results confirm the RPC based on MMC is effective in reducing the harmonic contents, solving the problem of three-phase current imbalance and compensating reactive power. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

21 pages, 3748 KiB  
Article
A Novel Arc Detection Method for DC Railway Systems
by Yljon Seferi, Steven M. Blair, Christian Mester and Brian G. Stewart
Energies 2021, 14(2), 444; https://doi.org/10.3390/en14020444 - 15 Jan 2021
Cited by 13 | Viewed by 3761
Abstract
Electric arcing due to contact interruption between the pantograph and the overhead contact line in electrified railway networks is an important and unwanted phenomenon. Arcing events are short-term power quality disturbances that produce significant electromagnetic disturbances both conducted and radiated as well as [...] Read more.
Electric arcing due to contact interruption between the pantograph and the overhead contact line in electrified railway networks is an important and unwanted phenomenon. Arcing events are short-term power quality disturbances that produce significant electromagnetic disturbances both conducted and radiated as well as increased degradation on contact wire and contact strip of the pantograph. Early-stage detection can prevent further deterioration of the current collection quality, reduce excessive wear in the pantograph-catenary system, and mitigate failure of the pantograph contact strip. This paper presents a novel arc detection method for DC railway networks. The method quantifies the rate-of-change of the instantaneous phase of the oscillating pantograph current signal during an arc occurrence through the Hilbert transform. Application of the method to practical pantograph current data measurements, demonstrates that phase derivative is a useful parameter for detecting and localizing significant power quality disturbances due to electric arcs during both coasting and regenerative braking phases of a running locomotive. The detected number of arcs may be used to calculate the distribution of the arcs per kilometre as an alternative estimation of the current collection quality index and consequently used to assess the pantograph-catenary system performance. The detected arc number may also contribute to lowering predictive maintenance costs of pantograph-catenary inspections works as these can be performed only at determined sections of the line extracted by using arcing time locations and speed profiles of the locomotive. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Graphical abstract

17 pages, 4802 KiB  
Article
A Novel Co-Phase Power-Supply System Based on Modular Multilevel Converter for High-Speed Railway AT Traction Power-Supply System
by Si Wu, Mingli Wu and Yi Wang
Energies 2021, 14(1), 253; https://doi.org/10.3390/en14010253 - 05 Jan 2021
Cited by 12 | Viewed by 3040
Abstract
The existing problems of the traction power-supply system (i.e., the existence of the neutral section and the power quality problems) limit the development of railways, especially high-speed railways, which are developing rapidly worldwide. The existence of the neutral section leads to the speed [...] Read more.
The existing problems of the traction power-supply system (i.e., the existence of the neutral section and the power quality problems) limit the development of railways, especially high-speed railways, which are developing rapidly worldwide. The existence of the neutral section leads to the speed loss and traction loss as well as mechanical failures, all of which threaten the fast and safe operation of the train and the system. Meanwhile, the power quality problems (e.g., the negative sequence current, the reactive power, and the harmonic) can bring a series of problems that cannot be ignored on the three-phase grid side. In response, many researchers have proposed co-phase power-supply schemes to solve these two problems simultaneously. Given that the auto-transformer (AT) power-supply mode has become the main power-supply mode for the high-speed railway traction power-supply system, it has a bright future following the rapid development of the high-speed railway. In addition, there is no co-phase power-supply scheme designed for AT power-supply mode in the existing schemes. Therefore, the main contribution of this paper is to propose a specifically designed power-supply mode more suitable for the AT, as well as to establish the control systems for the rectifier side and the inverter side. In addition, for the proposed scheme, the operation principle is analyzed, the mathematical model is built, and the control system is created, and its functionality is verified by simulation, and its advantages are compared and summarized finally. The result proves that it can meet functional requirements. At the same time, compared with the existing co-phase power-supply scheme, it saves an auto-transformer in terms of topology, reduces the current stress by 10.9% in terms of the current stress of the switching device, and reduces the power loss by 0.25% in terms of the entire system power loss, which will result in a larger amount of electricity being saved. All of this makes it a more suitable co-phase power-supply scheme for the AT power-supply mode. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Graphical abstract

17 pages, 3801 KiB  
Article
Four-Quadrant Operations of Bidirectional Chargers for Electric Vehicles in Smart Car Parks: G2V, V2G, and V4G
by Tingting He, Dylan Dah-Chuan Lu, Mingli Wu, Qinyao Yang, Teng Li and Qiujiang Liu
Energies 2021, 14(1), 181; https://doi.org/10.3390/en14010181 - 31 Dec 2020
Cited by 17 | Viewed by 4115
Abstract
This paper presents the four-quadrant operation modes of bidirectional chargers for electric vehicles (EVs) framed in smart car parks. A cascaded model predictive control (MPC) scheme for the bidirectional two-stage off-board chargers is proposed. The controller is constructed in two stages. The model [...] Read more.
This paper presents the four-quadrant operation modes of bidirectional chargers for electric vehicles (EVs) framed in smart car parks. A cascaded model predictive control (MPC) scheme for the bidirectional two-stage off-board chargers is proposed. The controller is constructed in two stages. The model predictive direct power control for the grid side is applied to track the active/reactive power references. The model predictive direct current control is proposed to achieve constant current charging/discharging for the EV load side. With this MPC strategy, EV chargers are able to transmit the active and reactive powers between the EV batteries and the power grid. Apart from exchanging the active power, the vehicle-for-grid (V4G) mode is proposed, where the chargers are used to deliver the reactive power to support the grid, simultaneously combined with grid-to-vehicle or vehicle-to-grid operation modes. In the V4G mode, the EV battery functions as the static var compensator. According to the simulation results, the system can operate effectively in the full control regions of the active and reactive power (PQ) plane under the aforementioned operation modes. Fast dynamic response and great steady-state system performances can be verified through various simulation and experimental results. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Graphical abstract

16 pages, 6848 KiB  
Article
Decentralized Control Strategy for an AC Co-Phase Traction Microgrid
by Lan Ma, Yuhua Du, Leilei Zhu, Fan Yang, Shibiao Xiang and Zeliang Shu
Energies 2021, 14(1), 7; https://doi.org/10.3390/en14010007 - 22 Dec 2020
Viewed by 1926
Abstract
High speed and heavy loads have become more prevalent in the traction power supply system recently. To ensure system operating stability, better power quality, and sufficient power capacity, improvements are needed over the conventional traction system. Inspired by the concept of a microgrid [...] Read more.
High speed and heavy loads have become more prevalent in the traction power supply system recently. To ensure system operating stability, better power quality, and sufficient power capacity, improvements are needed over the conventional traction system. Inspired by the concept of a microgrid (MG), an AC co-phase traction MG system was proposed. Substations were connected to the traction grid as distributed generators operate in islanded mode. Droop control was adopted as the primary control to stabilize the system’s operating frequency and voltage. Considering the operating features of the substation and locomotive load, a de-centralized secondary control strategy was proposed for AC co-phase traction MG system operation with enhanced resiliency. The proposed control strategy could increase system stability and prevent circulation currents between substations. Moreover, the proposed de-centralized coordination between substations does not rely on communication, which promotes the system’s “plug-and-play” functionality. Stability analysis was undertaken and the proposed controller was proved to be exponentially stable. The dynamic response of the proposed controller was validated using comprehensive case studies in MATLAB/Simulink. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

21 pages, 19540 KiB  
Article
Application of a Non-carrier-Based Modulation for Current Harmonics Spectrum Control during Regenerative Braking of the Electric Vehicle
by Marcin Steczek, Piotr Chudzik and Adam Szeląg
Energies 2020, 13(24), 6686; https://doi.org/10.3390/en13246686 - 18 Dec 2020
Cited by 8 | Viewed by 2216
Abstract
The regenerative braking of railway vehicles is widely used in DC railway systems all over the world. This mode of operation provides an opportunity to reuse part of the energy consumed by vehicles, and makes the railway system more energy efficient. During regenerative [...] Read more.
The regenerative braking of railway vehicles is widely used in DC railway systems all over the world. This mode of operation provides an opportunity to reuse part of the energy consumed by vehicles, and makes the railway system more energy efficient. During regenerative braking, not only energy management is an issue, but also Electromagnetic Compatibility EMC issues, such as interference of generated current harmonics with a railway signaling system. In this paper, the selective harmonic elimination modulation technique (SHE-PWM) was introduced to the traction drive with a three-level inverter to reduce specific catenary current harmonics generated during regenerative braking. The simulation model of a traction drive appropriate for harmonics analysis was proposed and verified by the measurements in the low-power laboratory drive system. The model was re-scaled to the 3 kV DC system for further study. The model of an induction motor with electromotive force and the method of its calculation was proposed. Furthermore, an analysis of the braking chopper operation was carried out. The asymmetric control of braking chopper was proposed to reduce the current harmonics below limits during chopper operation. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

16 pages, 4760 KiB  
Article
Harmonic Overvoltage Analysis of Electric Railways in a Wide Frequency Range Based on Relative Frequency Relationships of the Vehicle–Grid Coupling System
by Qiujiang Liu, Binghan Sun, Qinyao Yang, Mingli Wu and Tingting He
Energies 2020, 13(24), 6672; https://doi.org/10.3390/en13246672 - 17 Dec 2020
Cited by 2 | Viewed by 1585
Abstract
Harmonic overvoltage in electric railway traction networks can pose a serious threat to the safe and stable operation of the traction power supply system (TPSS). Existing studies aim at improving the control damping of grid-connected converters, neglecting the impedance frequency characteristics (IFCs) of [...] Read more.
Harmonic overvoltage in electric railway traction networks can pose a serious threat to the safe and stable operation of the traction power supply system (TPSS). Existing studies aim at improving the control damping of grid-connected converters, neglecting the impedance frequency characteristics (IFCs) of the actual TPSS. The applicable frequency range of these studies is relatively low, usually no more than half of the switching frequency, and there is a large gap with the actual traction network harmonic overvoltage frequency range of 750 Hz–3750 Hz. In this paper, first, the IFCs of the actual TPSS in the wide frequency range of 150 Hz–5000 Hz are obtained through field tests, and the resonant frequency distribution characteristics of TPSS are analyzed. After that, the aliasing effect of the sampling process and the sideband effect of the modulation process of the digital control of the grid-connected converter are considered. Based on the relative relationships among the inherent resonant frequency of the TPSS, sampling frequency and switching frequency, an impedance matching analysis method is proposed for the wide frequency range of the vehicle–grid coupling system. By this method, the sampling frequency and switching frequency can be decoupled, and the harmonic overvoltage of traction network in the frequency range of two times switching frequency and above can be directly estimated. Finally, the method proposed in this paper is validated by the comparative simulation analysis of seven different cases. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

25 pages, 2428 KiB  
Article
New Reactive Power Compensation Strategies for Railway Infrastructure Capacity Increasing
by Vítor A. Morais, João L. Afonso, Adriano S. Carvalho and António P. Martins
Energies 2020, 13(17), 4379; https://doi.org/10.3390/en13174379 - 25 Aug 2020
Cited by 13 | Viewed by 2712
Abstract
In AC railway electrification systems, the impact of reactive power flow in the feeding voltage magnitude is one aspect contributing to the quality of supply degradation. Specifically, this issue results in limitations in the infrastructure capacity, either in the maximum number of trains [...] Read more.
In AC railway electrification systems, the impact of reactive power flow in the feeding voltage magnitude is one aspect contributing to the quality of supply degradation. Specifically, this issue results in limitations in the infrastructure capacity, either in the maximum number of trains and in maximum train power. In this paper, two reactive power compensation strategies are presented and compared, in terms of the theoretical railway infrastructure capacity. The first strategy considers a static VAR compensator, located in the neutral zone and compensating the substation reactive power, achieving a maximum capacity increase up to 50% without depending on each train active power. The second strategy adapts each train reactive power, achieving also a capacity increase around 50%, only with an increase of the train apparent power below 10%. With a smart metering infrastructure, the implementation of such compensation strategy is viable, satisfying the requirements of real-time knowledge of the railway electrification system state. Specifically, the usage of droop curves to adapt in real time the compensation scheme can bring the operation closer to optimality. Thus, the quality of supply and the infrastructure capacity can be increased with a mobile reactive power compensation scheme, based on a smart metering framework. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Graphical abstract

Review

Jump to: Research

35 pages, 15183 KiB  
Review
Power Quality Phenomena in Electric Railway Power Supply Systems: An Exhaustive Framework and Classification
by Hamed Jafari Kaleybar, Morris Brenna, Federica Foiadelli, Seyed Saeed Fazel and Dario Zaninelli
Energies 2020, 13(24), 6662; https://doi.org/10.3390/en13246662 - 17 Dec 2020
Cited by 46 | Viewed by 4674
Abstract
Electric railway power systems (ERPS) as one of the most critical and high-power end-user loads of utility grids are characterized by outlandish power quality (PQ) problems all over the world. The extension and evolution of different supply topologies for these systems has resulted [...] Read more.
Electric railway power systems (ERPS) as one of the most critical and high-power end-user loads of utility grids are characterized by outlandish power quality (PQ) problems all over the world. The extension and evolution of different supply topologies for these systems has resulted in significant and various forms of distortions in network voltage and current in all ERPS, the connected power system, and adjacent consumers. During the last years, numerous studies have been offered to investigate various aspects of PQs in a specific supplying topology. Variation in the supply structure of the ERPS and different types of locomotives has propelled the observation of different PQ phenomena. This versatility and development have led to confront considerable types of two-way interactive interfaces as well as reliability and PQ problems in ERPS. In addition, the lack of standards explicitly dedicated to ERPS has added to the ambiguity and complexity of this issue. In this paper, an extensive review of PQ distortions and phenomena in different configurations of ERPS is proposed and a systematic classification is presented. More than 140 scientific papers and publications are studied and categorized which can provide a fast review and a perfect perspective on the status of PQ indexes for researchers and experts. Full article
(This article belongs to the Special Issue Power Quality in Electrified Transportation Systems)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-16
Back to TopTop