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Special Issue "Electrical Power and Energy Systems for Transportation Applications"

A special issue of Energies (ISSN 1996-1073).

Deadline for manuscript submissions: closed (30 April 2015)

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

Special Issue Editors

Guest Editor
Prof. Dr. Paul Stewart

Institute for Innovation in Sustainable Engineering, Lonsdale House, Derby, DE1 3EE, UK
Website | E-Mail
Interests: complex system simulation, design and optimization; engineering applications of artificial intelligence; advanced control systems; power and energy architectures; electrical machines, drives and systems; energy conversion and storage; remote monitoring and sensing; prognostics and diagnostics; low carbon and low emissions operations
Guest Editor
Prof. Dr. Chris Bingham

School of Engineering, University of Lincoln, Brayford Pool Lincoln, LN6 7TS, UK
Website | E-Mail
Interests: aircraft dynamics and advanced control; impact of driver behavior on energy efficiency of EVs/HEVs, electrical power distribution for deep-sea ROVs; power electronic servo-drive systems; real-time prognostics and diagnostics for industrial systems; sensor validation and fault detection; high-efficiency power supplies for domestic products; active magnetic bearings for high-speed energy storage

Special Issue Information

Dear colleagues, greetings from the Special Issue Editors.

We are inviting submissions to a Special Issue of Energies Journal on the subject area of “Electrical Power and Energy Systems for Transportation Applications”. Electrical power and energy systems are at the forefront of application developments in, for example, more-electric and all-electric aircraft, electric and hybrid road vehicles and marine propulsion applications. The associated hardware, technologies and control methods are crucial to achieving critical global targets in energy efficiency, low-carbon and low-emissions operations. The greatest challenges occur when we combine new technologies at large-scale and often complex system levels.

Topics of interest for publication include, but are not limited to:

  • Novel Electrical Power Systems architectures and technologies;
  • Energy vectors, integration with renewables, power and energy dense machines, converters and energy storage;
  • Air, land and sea vehicles; electrical propulsion and actuation for land, sea and air vehicles;
  • Electrical Machines, Drives, Systems and Applications—AC and DC machines and drives;
  • Multiscale systems modeling; remote monitoring and diagnosis;
  • Power Electronic Systems—Converters and emerging technologies;
  • Modeling simulation and control, reliability and fault tolerance, safety critical operation;
  • Electrical Power Generation Systems—Modeling and simulation of electrical power systems;
  • Load management; power quality; distribution reliability; distributed and islanded power systems, sensor networks, communication and control;
  • Electrical Power Systems Modeling and Control—Modeling and control methodologies and applications;
  • Intelligent systems; optimization and advanced heuristics; adaptive systems; robust control.

Prof. Dr. Paul Stewart
Prof. Dr. Chris Bingham
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 papers will be 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 monthly 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 1600 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

  • electrical power and energy systems
  • energy management
  • electrical machines and drives
  • power electronics
  • energy conversion
  • power generation
  • distributed power systems
  • hybrid and electric vehicles
  • more-electric aircraft
  • all-electric aircraft
  • electrical propulsion and actuation
  • power distribution architectures

Published Papers (26 papers)

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Editorial

Jump to: Research

Open AccessEditorial Electrical Power and Energy Systems for Transportation Applications
Energies 2016, 9(7), 545; doi:10.3390/en9070545
Received: 11 July 2016 / Accepted: 13 July 2016 / Published: 14 July 2016
PDF Full-text (1092 KB) | HTML Full-text | XML Full-text
Abstract
This book contains the successful invited submissions [1–25] to a Special Issue of Energies on the subject area of “Electrical Power and Energy Systems for Transportation Applications”. Full article

Research

Jump to: Editorial

Open AccessArticle Energy Consumption Prediction for Electric Vehicles Based on Real-World Data
Energies 2015, 8(8), 8573-8593; doi:10.3390/en8088573
Received: 30 April 2015 / Revised: 30 July 2015 / Accepted: 3 August 2015 / Published: 12 August 2015
Cited by 23 | PDF Full-text (898 KB) | HTML Full-text | XML Full-text
Abstract
Electric vehicle (EV) energy consumption is variable and dependent on a number of external factors such as road topology, traffic, driving style, ambient temperature, etc. The goal of this paper is to detect and quantify correlations between the kinematic parameters of the vehicle
[...] Read more.
Electric vehicle (EV) energy consumption is variable and dependent on a number of external factors such as road topology, traffic, driving style, ambient temperature, etc. The goal of this paper is to detect and quantify correlations between the kinematic parameters of the vehicle and its energy consumption. Real-world data of EV energy consumption are used to construct the energy consumption calculation models. Based on the vehicle dynamics equation as underlying physical model, multiple linear regression is used to construct three models. Each model uses a different level of aggregation of the input parameters, allowing predictions using different types of available input parameters. One model uses aggregated values of the kinematic parameters of trips. This model allows prediction with basic, easily available input parameters such as travel distance, travel time, and temperature. The second model extends this by including detailed acceleration data. The third model uses the raw data of the kinematic parameters as input parameters to predict the energy consumption. Using detailed values of kinematic parameters for the prediction in theory increases the link between the statistical model and its underlying physical principles, but requires these parameters to be available as input in order to make predictions. The first two models show similar results. The third model shows a worse fit than the first two, but has a similar accuracy. This model has great potential for future improvement. Full article
Open AccessArticle Comparative Study of Surface Temperature Behavior of Commercial Li-Ion Pouch Cells of Different Chemistries and Capacities by Infrared Thermography
Energies 2015, 8(8), 8175-8192; doi:10.3390/en8088175
Received: 1 May 2015 / Revised: 20 July 2015 / Accepted: 30 July 2015 / Published: 5 August 2015
Cited by 13 | PDF Full-text (3688 KB) | HTML Full-text | XML Full-text
Abstract
The non-uniform surface temperature distribution of a battery cell results from complex reactions inside the cell and makes efficient thermal management a challenging task. This experimental work attempts to determine the evolution of surface temperature distribution of three pouch type commercial cells: Nickel
[...] Read more.
The non-uniform surface temperature distribution of a battery cell results from complex reactions inside the cell and makes efficient thermal management a challenging task. This experimental work attempts to determine the evolution of surface temperature distribution of three pouch type commercial cells: Nickel Manganese Cobalt oxide (NMC)-based 20 Ah cell, Lithium Iron Phosphate (LFP) 14 Ah, and Lithium Titanate Oxide (LTO) 5 Ah battery cell by using contact thermistor and infrared (IR) thermography. High current (up to 100 A) continuous charge/discharge and high current (80 A) micro pulse cycling profile were applied on the cells. It was found that thermistor based temperature profile varied cell to cell, especially the LTO cell. Among the investigated cells, the NMC cell shows highest temperature rise and the LTO cell the lowest rise. IR (Infrared) images revealed the spatial distribution of surface temperature, in particular the location of the hottest region varies depending not only on the geometrical and material properties of the cell, but also the type of loads applied on the cells. Finally, a modeling perspective of the cell temperature non-uniformity is also discussed. Full article
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Open AccessArticle Space Charge Behavior in Paper Insulation Induced by Copper Sulfide in High-Voltage Direct Current Power Transformers
Energies 2015, 8(8), 8110-8120; doi:10.3390/en8088110
Received: 13 June 2015 / Revised: 15 July 2015 / Accepted: 27 July 2015 / Published: 5 August 2015
Cited by 3 | PDF Full-text (1399 KB) | HTML Full-text | XML Full-text
Abstract
The main insulation system in high-voltage direct current (HVDC) transformer consists of oil-paper insulation. The formation of space charge in insulation paper is crucial for the dielectric strength. Unfortunately, space charge behavior changes because of the corrosive sulfur substance in oil. This paper
[...] Read more.
The main insulation system in high-voltage direct current (HVDC) transformer consists of oil-paper insulation. The formation of space charge in insulation paper is crucial for the dielectric strength. Unfortunately, space charge behavior changes because of the corrosive sulfur substance in oil. This paper presents the space charge behavior in insulation paper induced by copper sulfide generated by corrosive sulfur in insulation oil. Thermal aging tests of paper-wrapped copper strip called the pigtail model were conducted at 130 °C in laboratory. Scanning electron microscopy (SEM) was used to observe the surface of copper and paper. Pulse electroacoustic (PEA) and thermally stimulated current (TSC) methods were used to obtain the space charge behavior in paper. Results showed that both maximum and total amount of space charge increased for the insulation paper contaminated by semi-conductor chemical substance copper sulfide. The space charge decay rate of contaminated paper was significantly enhanced after the polarization voltage was removed. The TSC results revealed that copper sulfide increased the trap density and lowered the shallow trap energy levels. These results contributed to charge transportation by de-trapping and trapping processes. This improved charge transportation could be the main reason for the decreased breakdown voltage of paper insulation material. Full article
Open AccessArticle Numerical Analysis on Combustion Characteristic of Leaf Spring Rotary Engine
Energies 2015, 8(8), 8086-8109; doi:10.3390/en8088086
Received: 19 March 2015 / Revised: 12 July 2015 / Accepted: 17 July 2015 / Published: 4 August 2015
Cited by 3 | PDF Full-text (1954 KB) | HTML Full-text | XML Full-text
Abstract
The purpose of this paper is to investigate combustion characteristics for rotary engine via numerical studies. A 3D numerical model was developed to study the influence of several operative parameters on combustion characteristics. A novel rotary engine called, “Leaf Spring Rotary Engine”, was
[...] Read more.
The purpose of this paper is to investigate combustion characteristics for rotary engine via numerical studies. A 3D numerical model was developed to study the influence of several operative parameters on combustion characteristics. A novel rotary engine called, “Leaf Spring Rotary Engine”, was used to illustrate the structure and principle of the engine. The aims are to (1) improve the understanding of combustion process, and (2) quantify the influence of rotational speed, excess air ratio, initial pressure and temperature on combustion characteristics. The chamber space changed with crankshaft rotation. Due to the complexity of chamber volume, an equivalent modeling method was presented to simulate the chamber space variation. The numerical simulations were performed by solving the incompressible, multiphase Unsteady Reynolds-Averaged Navier–Stokes Equations via the commercial code FLUENT using a transport equation-based combustion model; a realizable turbulence model and finite-rate/eddy-dissipation model were used to account for the effect of local factors on the combustion characteristics. Full article
Open AccessArticle Stability Analysis for Li-Ion Battery Model Parameters and State of Charge Estimation by Measurement Uncertainty Consideration
Energies 2015, 8(8), 7729-7751; doi:10.3390/en8087729
Received: 16 May 2015 / Revised: 26 June 2015 / Accepted: 22 July 2015 / Published: 29 July 2015
Cited by 14 | PDF Full-text (701 KB) | HTML Full-text | XML Full-text
Abstract
Accurate estimation of model parameters and state of charge (SoC) is crucial for the lithium-ion battery management system (BMS). In this paper, the stability of the model parameters and SoC estimation under measurement uncertainty is evaluated by three different factors: (i) sampling periods
[...] Read more.
Accurate estimation of model parameters and state of charge (SoC) is crucial for the lithium-ion battery management system (BMS). In this paper, the stability of the model parameters and SoC estimation under measurement uncertainty is evaluated by three different factors: (i) sampling periods of 1/0.5/0.1 s; (ii) current sensor precisions of ±5/±50/±500 mA; and (iii) voltage sensor precisions of ±1/±2.5/±5 mV. Firstly, the numerical model stability analysis and parametric sensitivity analysis for battery model parameters are conducted under sampling frequency of 1–50 Hz. The perturbation analysis is theoretically performed of current/voltage measurement uncertainty on model parameter variation. Secondly, the impact of three different factors on the model parameters and SoC estimation was evaluated with the federal urban driving sequence (FUDS) profile. The bias correction recursive least square (CRLS) and adaptive extended Kalman filter (AEKF) algorithm were adopted to estimate the model parameters and SoC jointly. Finally, the simulation results were compared and some insightful findings were concluded. For the given battery model and parameter estimation algorithm, the sampling period, and current/voltage sampling accuracy presented a non-negligible effect on the estimation results of model parameters. This research revealed the influence of the measurement uncertainty on the model parameter estimation, which will provide the guidelines to select a reasonable sampling period and the current/voltage sensor sampling precisions in engineering applications. Full article
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Open AccessArticle A Novel Grouping Method for Lithium Iron Phosphate Batteries Based on a Fractional Joint Kalman Filter and a New Modified K-Means Clustering Algorithm
Energies 2015, 8(8), 7703-7728; doi:10.3390/en8087703
Received: 27 May 2015 / Revised: 1 July 2015 / Accepted: 22 July 2015 / Published: 28 July 2015
Cited by 5 | PDF Full-text (2410 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents a novel grouping method for lithium iron phosphate batteries. In this method, a simplified electrochemical impedance spectroscopy (EIS) model is utilized to describe the battery characteristics. Dynamic stress test (DST) and fractional joint Kalman filter (FJKF) are used to extract
[...] Read more.
This paper presents a novel grouping method for lithium iron phosphate batteries. In this method, a simplified electrochemical impedance spectroscopy (EIS) model is utilized to describe the battery characteristics. Dynamic stress test (DST) and fractional joint Kalman filter (FJKF) are used to extract battery model parameters. In order to realize equal-number grouping of batteries, a new modified K-means clustering algorithm is proposed. Two rules are designed to equalize the numbers of elements in each group and exchange samples among groups. In this paper, the principles of battery model selection, physical meaning and identification method of model parameters, data preprocessing and equal-number clustering method for battery grouping are comprehensively described. Additionally, experiments for battery grouping and method validation are designed. This method is meaningful to application involving the grouping of fresh batteries for electric vehicles (EVs) and screening of aged batteries for recycling. Full article
Open AccessArticle Characteristic Analysis and Control of a Hybrid Excitation Linear Eddy Current Brake
Energies 2015, 8(7), 7441-7464; doi:10.3390/en8077441
Received: 31 March 2015 / Revised: 22 June 2015 / Accepted: 17 July 2015 / Published: 22 July 2015
Cited by 2 | PDF Full-text (1466 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, a novel hybrid excitation linear eddy current brake is presented as a braking system for high-speed road and rail vehicles. The presence of the permanent magnets (PMs), whose flux lines in the primary core are oppositely directed with respect to
[...] Read more.
In this paper, a novel hybrid excitation linear eddy current brake is presented as a braking system for high-speed road and rail vehicles. The presence of the permanent magnets (PMs), whose flux lines in the primary core are oppositely directed with respect to the flux lines by the excitation windings, has the effect of mitigating the saturation of the iron in the teeth of the primary core. This allows the brake to be fed with more intense currents, improving the braking force. First, using the magnetic equivalent circuit method and the layer theory approach, the analytical model of the hybrid excitation linear eddy current brake was developed, which can account for the saturation effects occurring in the iron parts. The saturation effects make the design and control of eddy current brakes more difficult. Second, the relationship between the braking force characteristics and the design parameters were analyzed to provide useful information to the designers of eddy current brakes. Then, the controller of the hybrid excitation linear eddy current brake was designed to control the amplitude of the braking force. Finally, experimental measurements were conducted to verify the validity of the theoretical analysis. Full article
Open AccessArticle Improved Adaptive Droop Control Design for Optimal Power Sharing in VSC-MTDC Integrating Wind Farms
Energies 2015, 8(7), 7100-7121; doi:10.3390/en8077100
Received: 28 April 2015 / Revised: 24 June 2015 / Accepted: 7 July 2015 / Published: 14 July 2015
Cited by 5 | PDF Full-text (480 KB) | HTML Full-text | XML Full-text
Abstract
With the advance of insulated gate bipolar transistor (IGBT) converters, Multi-Terminal DC (MTDC) based on the voltage-source converter (VSC) has developed rapidly in renewable and electric power systems. To reduce the copper loss of large capacity and long distance DC transmission line, an
[...] Read more.
With the advance of insulated gate bipolar transistor (IGBT) converters, Multi-Terminal DC (MTDC) based on the voltage-source converter (VSC) has developed rapidly in renewable and electric power systems. To reduce the copper loss of large capacity and long distance DC transmission line, an improved droop control design based on optimal power sharing in VSC-MTDC integrating offshore wind farm is proposed. The proposed approach provided a calculation method for power-voltage droop coefficients under two different scenarios either considering local load or not. The available headroom of each converter station was considered as a converter outage, to participate in the power adjustment according to their ability. A four-terminal MTDC model system including two large scale wind farms was set up in PSCAD/EMTDC. Then, the proposed control strategy was verified through simulation under the various conditions, including wind speed variation, rectifier outage and inverter outage, and a three-phase short-circuit of the converter. Full article
Open AccessArticle Battery Design for Successful Electrification in Public Transport
Energies 2015, 8(7), 6715-6737; doi:10.3390/en8076715
Received: 24 April 2015 / Revised: 16 June 2015 / Accepted: 19 June 2015 / Published: 30 June 2015
Cited by 6 | PDF Full-text (2752 KB) | HTML Full-text | XML Full-text
Abstract
Public transport is an especially promising sector for full electric vehicles due to the high amount of cycles and predictable workload. This leads to a high amount of different vehicle concepts ranging from large batteries, designed for a full day of operation without
[...] Read more.
Public transport is an especially promising sector for full electric vehicles due to the high amount of cycles and predictable workload. This leads to a high amount of different vehicle concepts ranging from large batteries, designed for a full day of operation without charging, to fast-charging systems with charging power up to a few hundred kilowatts. Hence, many different issues have to be addressed in the whole design and production process regarding high-voltage (HV) batteries for buses. In this work, the design process for electric public buses is analyzed in detail, based on two systems developed by the research projects Smart Wheels/econnect and SEB eÖPNV. The complete development process starting, with the demand analysis and the operating scenario, including the charging routine, is discussed. This paper also features details on cell selection and cost estimations as well as technical details on the system layout, such as the management system and passive components as well as thermal management. Full article
Open AccessArticle Credibility Theory-Based Available Transfer Capability Assessment
Energies 2015, 8(6), 6059-6078; doi:10.3390/en8066059
Received: 21 January 2015 / Revised: 24 May 2015 / Accepted: 11 June 2015 / Published: 18 June 2015
Cited by 2 | PDF Full-text (382 KB) | HTML Full-text | XML Full-text
Abstract
Since the development of large scale power grid interconnections and power markets, research on available transfer capability (ATC) has attracted great attention. The challenges for accurate assessment of ATC originate from the numerous uncertainties in electricity generation, transmission, distribution and utilization sectors. Power
[...] Read more.
Since the development of large scale power grid interconnections and power markets, research on available transfer capability (ATC) has attracted great attention. The challenges for accurate assessment of ATC originate from the numerous uncertainties in electricity generation, transmission, distribution and utilization sectors. Power system uncertainties can be mainly described as two types: randomness and fuzziness. However, the traditional transmission reliability margin (TRM) approach only considers randomness. Based on credibility theory, this paper firstly built models of generators, transmission lines and loads according to their features of both randomness and fuzziness. Then a random fuzzy simulation is applied, along with a novel method proposed for ATC assessment, in which both randomness and fuzziness are considered. The bootstrap method and multi-core parallel computing technique are introduced to enhance the processing speed. By implementing simulation for the IEEE-30-bus system and a real-life system located in Northwest China, the viability of the models and the proposed method is verified. Full article
Open AccessArticle Effects of Scavenging System Configuration on In-Cylinder Air Flow Organization of an Opposed-Piston Two-Stroke Engine
Energies 2015, 8(6), 5866-5884; doi:10.3390/en8065866
Received: 17 March 2015 / Revised: 12 May 2015 / Accepted: 9 June 2015 / Published: 17 June 2015
Cited by 4 | PDF Full-text (2090 KB) | HTML Full-text | XML Full-text
Abstract
In-cylinder air flow is very important from the point of view of mixture formation and combustion. In this direction, intake chamber structure and piston crown shape play a very crucial role for in-cylinder air pattern of opposed-piston two-stroke (OP2S) engines. This study is
[...] Read more.
In-cylinder air flow is very important from the point of view of mixture formation and combustion. In this direction, intake chamber structure and piston crown shape play a very crucial role for in-cylinder air pattern of opposed-piston two-stroke (OP2S) engines. This study is concerned with the three-dimensional (3D) computational fluid dynamics (CFD) analysis of in-cylinder air motion coupled with the comparison of predicted results with the zero-dimensional (0D) parametric model. Three configurations viz., a flat piston uniform scavenging chamber, a flat piston non-uniform scavenging chamber and a pit piston non-uniform scavenging chamber have been studied. 0D model analysis of in-cylinder air flow is consistent with 3D CFD simulation. It is concluded that a pit piston non-uniform scavenging chamber is the best design from the point of view of tumble ratio, turbulent kinetic energy and turbulent intensity, which play very important roles in imparting proper air motion. Meanwhile a flat piston uniform scavenging chamber can organize a higher swirl ratio and lower tumble ratio which is important to improve the scavenging process. Full article
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Open AccessArticle Analysis and Design of a Permanent Magnet Bi-Stable Electro-Magnetic Clutch Unit for In-Wheel Electric Vehicle Drives
Energies 2015, 8(6), 5598-5612; doi:10.3390/en8065598
Received: 9 March 2015 / Revised: 29 May 2015 / Accepted: 1 June 2015 / Published: 11 June 2015
Cited by 6 | PDF Full-text (1003 KB) | HTML Full-text | XML Full-text
Abstract
Clutches have been used in internal combustion vehicles and concentrated electric vehicles (EVs) to smoothen impulsion while starting and shifting. This paper proposes a permanent magnet bi-stable electromagnetic clutch unit (PMBECU) which is specially introduced into in-wheel EVs to make the rigid connection
[...] Read more.
Clutches have been used in internal combustion vehicles and concentrated electric vehicles (EVs) to smoothen impulsion while starting and shifting. This paper proposes a permanent magnet bi-stable electromagnetic clutch unit (PMBECU) which is specially introduced into in-wheel EVs to make the rigid connection between hub and wheel more flexible. Firstly, the operation principle of the PMBECU is illustrated. Then, the basic magnetic circuit model is presented and analyzed, followed by optimal design of the main structural parameters by investigating the PM leakage flux coefficient. Further, according to the basic electromagnetic characteristics of the PMBECU, the current pulse supply is put forward, and the minimum pulse width which enables the operation of the PMBECU and its dynamic characteristics are analyzed by an improved finite element method. Finally, a prototype machine is manufactured and tested to validate all the analysis results. Full article
Open AccessArticle Metamodel for Efficient Estimation of Capacity-Fade Uncertainty in Li-Ion Batteries for Electric Vehicles
Energies 2015, 8(6), 5538-5554; doi:10.3390/en8065538
Received: 4 April 2015 / Revised: 26 May 2015 / Accepted: 27 May 2015 / Published: 9 June 2015
Cited by 7 | PDF Full-text (1340 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents an efficient method for estimating capacity-fade uncertainty in lithium-ion batteries (LIBs) in order to integrate them into the battery-management system (BMS) of electric vehicles, which requires simple and inexpensive computation for successful application. The study uses the pseudo-two-dimensional (P2D) electrochemical
[...] Read more.
This paper presents an efficient method for estimating capacity-fade uncertainty in lithium-ion batteries (LIBs) in order to integrate them into the battery-management system (BMS) of electric vehicles, which requires simple and inexpensive computation for successful application. The study uses the pseudo-two-dimensional (P2D) electrochemical model, which simulates the battery state by solving a system of coupled nonlinear partial differential equations (PDEs). The model parameters that are responsible for electrode degradation are identified and estimated, based on battery data obtained from the charge cycles. The Bayesian approach, with parameters estimated by probability distributions, is employed to account for uncertainties arising in the model and battery data. The Markov Chain Monte Carlo (MCMC) technique is used to draw samples from the distributions. The complex computations that solve a PDE system for each sample are avoided by employing a polynomial-based metamodel. As a result, the computational cost is reduced from 5.5 h to a few seconds, enabling the integration of the method into the vehicle BMS. Using this approach, the conservative bound of capacity fade can be determined for the vehicle in service, which represents the safety margin reflecting the uncertainty. Full article
Open AccessArticle Protection Principle for a DC Distribution System with a Resistive Superconductive Fault Current Limiter
Energies 2015, 8(6), 4839-4852; doi:10.3390/en8064839
Received: 13 February 2015 / Accepted: 14 May 2015 / Published: 26 May 2015
Cited by 8 | PDF Full-text (802 KB) | HTML Full-text | XML Full-text
Abstract
A DC distribution system, which is suitable for access to distributed power generation and DC loads, is one of the development directions in power systems. Furthermore, it could greatly improve the energy efficiency and reduce the loss of power transportation. The huge short
[...] Read more.
A DC distribution system, which is suitable for access to distributed power generation and DC loads, is one of the development directions in power systems. Furthermore, it could greatly improve the energy efficiency and reduce the loss of power transportation. The huge short circuit current is always a great threat to the safety of the components, especially the capacitors and diodes. A resistive superconductive fault current limiter (SFCL), which could respond quickly once a fault happens and limit the fault current to a relatively low level, becomes a good solution to this problem. In this paper, the operational principle of the resistive SFCL is introduced first, and then, the DC short-circuit fault characteristic of the DC distribution system with the SFCL is analyzed and the effectiveness of the SFCL verified. In order to realize the selectivity of the protection in the DC distribution system with SFCL, a new transient current protection principle based on Ip (the peak value of the current) and tp (the transient time that the current takes to reach its peak value) is proposed. Finally, a model of a 10-kV DC distribution system with an SFCL is established and simulated in PSCAD/METDC. Simulation results have demonstrated the validity of the analysis and protection principle. Full article
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Open AccessArticle Fast Charging Battery Buses for the Electrification of Urban Public Transport—A Feasibility Study Focusing on Charging Infrastructure and Energy Storage Requirements
Energies 2015, 8(5), 4587-4606; doi:10.3390/en8054587
Received: 25 March 2015 / Revised: 8 May 2015 / Accepted: 15 May 2015 / Published: 21 May 2015
Cited by 23 | PDF Full-text (780 KB) | HTML Full-text | XML Full-text
Abstract
The electrification of public transport bus networks can be carried out utilizing different technological solutions, like trolley, battery or fuel cell buses. The purpose of this paper is to analyze how and to what extent existing bus networks can be electrified with fast
[...] Read more.
The electrification of public transport bus networks can be carried out utilizing different technological solutions, like trolley, battery or fuel cell buses. The purpose of this paper is to analyze how and to what extent existing bus networks can be electrified with fast charging battery buses. The so called opportunity chargers use mainly the regular dwell time at the stops to charge their batteries. This results in a strong linkage between the vehicle scheduling and the infrastructure planning. The analysis is based on real-world data of the bus network in Muenster, a mid-sized city in Germany. The outcomes underline the necessity to focus on entire vehicle schedules instead on individual trips. The tradeoff between required battery capacity and charging power is explained in detail. Furthermore, the impact on the electricity grid is discussed based on the load profiles of a selected charging station and a combined load profile of the entire network. Full article
Open AccessArticle Modeling and Simulation of DC Microgrids for Electric Vehicle Charging Stations
Energies 2015, 8(5), 4335-4356; doi:10.3390/en8054335
Received: 2 February 2015 / Revised: 17 April 2015 / Accepted: 6 May 2015 / Published: 13 May 2015
Cited by 11 | PDF Full-text (893 KB) | HTML Full-text | XML Full-text
Abstract
This paper focuses on the evaluation of theoretical and numerical aspects related to an original DC microgrid power architecture for efficient charging of plug-in electric vehicles (PEVs). The proposed DC microgrid is based on photovoltaic array (PVA) generation, electrochemical storage, and grid connection;
[...] Read more.
This paper focuses on the evaluation of theoretical and numerical aspects related to an original DC microgrid power architecture for efficient charging of plug-in electric vehicles (PEVs). The proposed DC microgrid is based on photovoltaic array (PVA) generation, electrochemical storage, and grid connection; it is assumed that PEVs have a direct access to their DC charger input. As opposed to conventional power architecture designs, the PVA is coupled directly on the DC link without a static converter, which implies no DC voltage stabilization, increasing energy efficiency, and reducing control complexity. Based on a real-time rule-based algorithm, the proposed power management allows self-consumption according to PVA power production and storage constraints, and the public grid is seen only as back-up. The first phase of modeling aims to evaluate the main energy flows within the proposed DC microgrid architecture and to identify the control structure and the power management strategies. For this, an original model is obtained by applying the Energetic Macroscopic Representation formalism, which allows deducing the control design using Maximum Control Structure. The second phase of simulation is based on the numerical characterization of the DC microgrid components and the energy management strategies, which consider the power source requirements, charging times of different PEVs, electrochemical storage ageing, and grid power limitations for injection mode. The simulation results show the validity of the model and the feasibility of the proposed DC microgrid power architecture which presents good performance in terms of total efficiency and simplified control. Full article
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Open AccessArticle Probabilistic Agent-Based Model of Electric Vehicle Charging Demand to Analyse the Impact on Distribution Networks
Energies 2015, 8(5), 4160-4187; doi:10.3390/en8054160
Received: 11 January 2015 / Revised: 15 April 2015 / Accepted: 29 April 2015 / Published: 11 May 2015
Cited by 11 | PDF Full-text (995 KB) | HTML Full-text | XML Full-text
Abstract
Electric Vehicles (EVs) have seen significant growth in sales recently and it is not clear how power systems will support the charging of a great number of vehicles. This paper proposes a methodology which allows the aggregated EV charging demand to be determined.
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Electric Vehicles (EVs) have seen significant growth in sales recently and it is not clear how power systems will support the charging of a great number of vehicles. This paper proposes a methodology which allows the aggregated EV charging demand to be determined. The methodology applied to obtain the model is based on an agent-based approach to calculate the EV charging demand in a certain area. This model simulates each EV driver to consider its EV model characteristics, mobility needs, and charging processes required to reach its destination. This methodology also permits to consider social and economic variables. Furthermore, the model is stochastic, in order to consider the random pattern of some variables. The model is applied to Barcelona’s (Spain) mobility pattern and uses the 37-node IEEE test feeder adapted to common distribution grid characteristics from Barcelona. The corresponding grid impact is analyzed in terms of voltage drop and four charging strategies are compared. The case study indicates that the variability in scenarios without control is relevant, but not in scenarios with control. Moreover, the voltages do not reach the minimum voltage allowed, but the MV/LV substations could exceed their capacities. Finally, it is determined that all EVs can charge during the valley without any negative effect on the distribution grid. In conclusion, it is determined that the methodology presented allows the EV charging demand to be calculated, considering different variables, to obtain better accuracy in the results. Full article
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Open AccessArticle Comparative Study of a Fault-Tolerant Multiphase Wound-Field Doubly Salient Machine for Electrical Actuators
Energies 2015, 8(5), 3640-3660; doi:10.3390/en8053640
Received: 3 November 2014 / Revised: 19 March 2015 / Accepted: 20 April 2015 / Published: 29 April 2015
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Abstract
New multiphase Wound-Field Doubly Salient Machines (WFDSMs) for electrical actuators with symmetric phases are investigated and compared in this paper. With a comparative study of the pole number and pole arc coefficient, the salient pole topology of the three-phase, four-phase, five-phase, and six-phase
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New multiphase Wound-Field Doubly Salient Machines (WFDSMs) for electrical actuators with symmetric phases are investigated and compared in this paper. With a comparative study of the pole number and pole arc coefficient, the salient pole topology of the three-phase, four-phase, five-phase, and six-phase WFDSMs with little cogging torque is presented. A new winding configuration that can provide symmetrical phases for the multiphase WFDSMs is proposed. Suitable fault-tolerant converters for the multiphase WFDSM are presented. With the simulated results in terms of the pole topology, flux linkage, back EMF and converters, it can be concluded that the pole numbers of the new five-phase WFDSM are very large. The high accuracy position sensors should be required to make the five-phase WFDSM commutate frequently and accurately at a high speed. The four-phase and the six-phase WFDSM can be divided into two isolated channels, and both of them have a good performance as a fault-tolerant machine. All of the investigations are verified by finite element analysis results. Full article
Open AccessArticle Estimation of State of Charge for Two Types of Lithium-Ion Batteries by Nonlinear Predictive Filter for Electric Vehicles
Energies 2015, 8(5), 3556-3577; doi:10.3390/en8053556
Received: 13 January 2015 / Revised: 3 April 2015 / Accepted: 20 April 2015 / Published: 28 April 2015
Cited by 10 | PDF Full-text (1626 KB) | HTML Full-text | XML Full-text
Abstract
Estimation of state of charge (SOC) is of great importance for lithium-ion (Li-ion) batteries used in electric vehicles. This paper presents a state of charge estimation method using nonlinear predictive filter (NPF) and evaluates the proposed method on the lithium-ion batteries with different
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Estimation of state of charge (SOC) is of great importance for lithium-ion (Li-ion) batteries used in electric vehicles. This paper presents a state of charge estimation method using nonlinear predictive filter (NPF) and evaluates the proposed method on the lithium-ion batteries with different chemistries. Contrary to most conventional filters which usually assume a zero mean white Gaussian process noise, the advantage of NPF is that the process noise in NPF is treated as an unknown model error and determined as a part of the solution without any prior assumption, and it can take any statistical distribution form, which improves the estimation accuracy. In consideration of the model accuracy and computational complexity, a first-order equivalent circuit model is applied to characterize the battery behavior. The experimental test is conducted on the LiCoO2 and LiFePO4 battery cells to validate the proposed method. The results show that the NPF method is able to accurately estimate the battery SOC and has good robust performance to the different initial states for both cells. Furthermore, the comparison study between NPF and well-established extended Kalman filter for battery SOC estimation indicates that the proposed NPF method has better estimation accuracy and converges faster. Full article
Open AccessArticle The Three-Phase Power Router and Its Operation with Matrix Converter toward Smart-Grid Applications
Energies 2015, 8(4), 3034-3046; doi:10.3390/en8043034
Received: 17 December 2014 / Revised: 22 March 2015 / Accepted: 2 April 2015 / Published: 17 April 2015
Cited by 3 | PDF Full-text (2983 KB) | HTML Full-text | XML Full-text
Abstract
A power router has been recently developed for both AC and DC applications that has the potential for smart-grid applications. This study focuses on three-phase power switching through the development of an experimental setup which consists of a three-phase direct AC/AC matrix converter
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A power router has been recently developed for both AC and DC applications that has the potential for smart-grid applications. This study focuses on three-phase power switching through the development of an experimental setup which consists of a three-phase direct AC/AC matrix converter with a power router attached to its output. Various experimental switching scenarios with the loads connected to different input sources were investigated. The crescent introduction of decentralized power generators throughout the power-grid obligates us to take measurements for a better distribution and management of the power. Power routers and matrix converters have great potential to succeed this goal with the help of power electronics devices. In this paper, a novel experimental three-phase power switching was achieved and the advantages of this operation are presented, such as on-demand and constant power supply at the desired loads. Full article
Open AccessArticle Research on a Small Signal Stability Region Boundary Model of the Interconnected Power System with Large-Scale Wind Power
Energies 2015, 8(4), 2312-2336; doi:10.3390/en8042312
Received: 4 December 2014 / Revised: 1 March 2015 / Accepted: 18 March 2015 / Published: 25 March 2015
Cited by 5 | PDF Full-text (841 KB) | HTML Full-text | XML Full-text
Abstract
For the interconnected power system with large-scale wind power, the problem of the small signal stability has become the bottleneck of restricting the sending-out of wind power as well as the security and stability of the whole power system. Around this issue, this
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For the interconnected power system with large-scale wind power, the problem of the small signal stability has become the bottleneck of restricting the sending-out of wind power as well as the security and stability of the whole power system. Around this issue, this paper establishes a small signal stability region boundary model of the interconnected power system with large-scale wind power based on catastrophe theory, providing a new method for analyzing the small signal stability. Firstly, we analyzed the typical characteristics and the mathematic model of the interconnected power system with wind power and pointed out that conventional methods can’t directly identify the topological properties of small signal stability region boundaries. For this problem, adopting catastrophe theory, we established a small signal stability region boundary model of the interconnected power system with large-scale wind power in two-dimensional power injection space and extended it to multiple dimensions to obtain the boundary model in multidimensional power injection space. Thirdly, we analyzed qualitatively the topological property’s changes of the small signal stability region boundary caused by large-scale wind power integration. Finally, we built simulation models by DIgSILENT/PowerFactory software and the final simulation results verified the correctness and effectiveness of the proposed model. Full article
Open AccessArticle MV and LV Residential Grid Impact of Combined Slow and Fast Charging of Electric Vehicles
Energies 2015, 8(3), 1760-1783; doi:10.3390/en8031760
Received: 16 December 2014 / Revised: 15 February 2015 / Accepted: 17 February 2015 / Published: 3 March 2015
Cited by 7 | PDF Full-text (1095 KB) | HTML Full-text | XML Full-text
Abstract
This article investigates the combined low voltage (LV) and medium voltage (MV) residential grid impact for slow and fast electric vehicle (EV) charging, for an increasing local penetration rate and for different residential slow charging strategies. A realistic case study for a Flemish
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This article investigates the combined low voltage (LV) and medium voltage (MV) residential grid impact for slow and fast electric vehicle (EV) charging, for an increasing local penetration rate and for different residential slow charging strategies. A realistic case study for a Flemish urban distribution grid is used, for which three residential slow charging strategies are modeled: uncoordinated charging, residential off-peak charging, and EV-based peak shaving. For each slow charging strategy, the EV hosting capacity is determined, with and without the possibility of fast charging, while keeping the grid within its operating limits. The results show that the distribution grid impact is much less sensitive to the presence of fast charging compared to the slow charging strategy. EV-based peak shaving results in the lowest grid impact, allowing for the highest EV hosting capacity. Residential off-peak charging has the highest grid impact, due the load synchronization effect that occurs, resulting in the lowest EV hosting capacity. Therefore, the EV users should be incentivized to charge their EVs in a more grid-friendly manner when the local EV penetration rate becomes significant, as this increases the EV hosting capacity much more than the presence of fast charging decreases it. Full article
Open AccessArticle Coordinated Charging Strategy for Electric Taxis in Temporal and Spatial Scale
Energies 2015, 8(2), 1256-1272; doi:10.3390/en8021256
Received: 5 December 2014 / Revised: 20 January 2015 / Accepted: 29 January 2015 / Published: 5 February 2015
Cited by 6 | PDF Full-text (723 KB) | HTML Full-text | XML Full-text
Abstract
Currently, electric taxis have been deployed in many cities of China. However, the charging unbalance in both temporal and spatial scale has become a rising problem, which leads to low charging efficiency or charging congestion in different stations or time periods. This paper
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Currently, electric taxis have been deployed in many cities of China. However, the charging unbalance in both temporal and spatial scale has become a rising problem, which leads to low charging efficiency or charging congestion in different stations or time periods. This paper presents a multi-objective coordinated charging strategy for electric taxis in the temporal and spatial scale. That is, the objectives are maximizing the utilization efficiency of charging facilities, minimizing the load unbalance of the regional power system and minimizing the customers’ cost. Besides, the basic configuration of a charging station and operation rules of electric taxis would be the constraints. To tackle this multi-objective optimizing problems, a fuzzy mathematical method has been utilized to transfer the multi-objective optimization to a single optimization issue, and furthermore, the Improved Particle Swarm Optimization (IPSO) Algorithm has been used to solve the optimization problem. Moreover, simulation cases are carried out, Case 1 is the original charging procedure, and Cases 2 and 3 are the temporal and spatial scale optimized separately, followed with Case 4, the combined coordinated charging. The simulation shows the significant improvement in charging facilities efficiency and users’ benefits, as well as the better dispatching of electric taxis’ charging loads. Full article
Open AccessArticle Energy Management of a Hybrid AC–DC Micro-Grid Based on a Battery Testing System
Energies 2015, 8(2), 1181-1194; doi:10.3390/en8021181
Received: 3 December 2014 / Revised: 14 January 2015 / Accepted: 28 January 2015 / Published: 3 February 2015
Cited by 5 | PDF Full-text (3479 KB) | HTML Full-text | XML Full-text
Abstract
Energy Recovery Battery Testing Systems (ERBTS) plays an important role in battery manufacture. The conventional ERBTS configuration contains a fundamental transformer, and a bidirectional Direct Current (DC)–DC and Alternating Current (AC)–DC converter. All ERBTS are connected in parallel, thus constituting a special and
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Energy Recovery Battery Testing Systems (ERBTS) plays an important role in battery manufacture. The conventional ERBTS configuration contains a fundamental transformer, and a bidirectional Direct Current (DC)–DC and Alternating Current (AC)–DC converter. All ERBTS are connected in parallel, thus constituting a special and complicated AC micro-grid system. Aiming at addressing their low energy recovery efficiency, complex grid-connected control algorithm issues for islanded detection, and complicated power circuit topology issues, a hierarchical DC-link voltage hybrid AC–DC micro-grid that contains composite energy storing devices is proposed. Moreover, an energy management optimal scheme for the proposed scheme is put forward. The system configuration of the proposed scheme is described in detail. Compared to the conventional scheme, the proposed scheme has the merits of simplified power circuit topology, no need for phase synchronous control, and much higher energy recovery efficiency and reliability. The validity and effectiveness of the proposed technique is verified through numerous experimental results. Full article
Open AccessArticle PID Controller Design for UPS Three-Phase Inverters Considering Magnetic Coupling
Energies 2014, 7(12), 8036-8055; doi:10.3390/en7128036
Received: 4 September 2014 / Revised: 16 November 2014 / Accepted: 25 November 2014 / Published: 28 November 2014
Cited by 3 | PDF Full-text (1007 KB) | HTML Full-text | XML Full-text
Abstract
In three-phase inverters used in uninterruptible power supplies (UPSs), three-limb inductors and three-limb transformers are commonly used in consideration of cost and size. However, magnetic coupling exists between the three phases of the inverter, which can result in complex models. When instantaneous feedback
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In three-phase inverters used in uninterruptible power supplies (UPSs), three-limb inductors and three-limb transformers are commonly used in consideration of cost and size. However, magnetic coupling exists between the three phases of the inverter, which can result in complex models. When instantaneous feedback control strategies are introduced to achieve high quality output waveforms, the transient analysis of the closed-loop inverters becomes difficult. In this paper, the phenomenon of magnetic coupling in three-phase inverters due to three-limb inductors and three-limb transformers is analyzed. A decoupled dynamic model is derived based on the instantaneous symmetrical components transformation, which comprises three decoupled equivalent circuits of instantaneous symmetrical components. Analyses based on this model indicate that magnetic coupling may have a significant impact on the performance of three-phase inverters under unbalanced load conditions and transient responses. For three-phase inverters in UPSs with Proportional-Integral-Differential (PID) closed-loop control strategies, the interactive influence between instantaneous closed-loop regulation and magnetic coupling is researched. Finally, a method of reliability analysis and PID controller design for inverters with magnetic coupling is derived. Simulation and experiment results validate the model and conclusions. Full article
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