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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Design Method for Power Generation Systems for Diesel Vehicles Using a Permanent Magnet Synchronous Machine and a Full-Bridge Rectifier</title>
      <link>https://trid.trb.org/View/2559632</link>
      <description><![CDATA[This paper describes a design optimization method for power generation systems for diesel vehicles consisting of a permanent magnet synchronous machine, a full-bridge rectifier and phase shift capacitors inserted between them. By combining an analysis method for the proposed systems and a multi-objective optimization method, a trial design optimization was carried out with the aim of minimizing indicators related to the size and weight of the system. Furthermore, the performance of the optimized design was verified by numerical simulations, and it was confirmed that the design achieved the required performance while satisfying the constraints of the system.]]></description>
      <pubDate>Fri, 18 Jul 2025 15:10:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2559632</guid>
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    <item>
      <title>Smart train control and monitoring system with predictive maintenance and secure communications features</title>
      <link>https://trid.trb.org/View/2534485</link>
      <description><![CDATA[Predictive maintenance is a proactive and data-driven approach to service maintenance that aims to identify potential problems before they occur. Modern trains have a sophisticated train control and monitoring system (TCMS), a vehicle processing unit to deliver train status conditions. On top of the proprietary TCMS system, the authors designed an intelligent TCMS fitted with two main functions. First, the data analytics features predict the product age and deliver real-time notifications. Second, a robust infrastructure for mobile conditions with data security protection exists. Thus, the authors named the solution as Smart TCMS. This research has designed a user-friendly dashboard to facilitate real-time condition monitoring and timely notification of any detected problems, focusing on different level component severity problems: air conditioning (low severity), battery (medium severity), and traction system components (high severity). This solution has been implemented on an electric diesel train, an Indonesian Rolling Stock Industry (INKA) product.]]></description>
      <pubDate>Fri, 16 May 2025 09:33:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534485</guid>
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    <item>
      <title>Rule-Based Energy Management Strategy for Multi-energy Drive System</title>
      <link>https://trid.trb.org/View/1975803</link>
      <description><![CDATA[Energy management plays an important role in improving the fuel economy and reducing emissions of multi-energy drive system. This paper focuses on the rule-based energy management strategy for multi-energy drive system of “diesel generator + battery.” It mainly focused on the optimization of the following three aspects: control of diesel generator sets, control of power battery packs, and load energy management. Moreover, simulation results have verified that the rule-based energy management strategy can operate stably in the multi-energy drive system, realize the power distribution of the two power sources, and make the system run in the low-consumption and high-efficiency area.]]></description>
      <pubDate>Fri, 23 Aug 2024 15:26:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1975803</guid>
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    <item>
      <title>Evaluation of Rail Decarbonization Alternatives: Framework and Application</title>
      <link>https://trid.trb.org/View/2173516</link>
      <description><![CDATA[The Northwestern University Freight Rail Infrastructure & Energy Network Decarbonization (NUFRIEND) framework is a comprehensive industry-oriented tool for simulating the deployment of new energy technologies including biofuels, e-fuels, battery-electric, and hydrogen locomotives. By classifying fuel types into two categories based on deployment requirements, the associated optimal charging/fueling facility location and sizing problem are solved with a five-step framework. Life-cycle analysis (LCA) and techno-economic analysis (TEA) are used to estimate carbon reduction, capital investments, cost of carbon reduction, and operational impacts, enabling sensitivity analysis with operational and technological parameters. The framework is illustrated on lower-carbon drop-in fuels as well as battery-electric technology deployments for the US Eastern and Western Class I railroad networks. Drop-in fuel deployments are modeled as admixtures with diesel in existing locomotives, while battery-electric deployments are shown for varying technology penetration levels and locomotive ranges. When mixed in a 50% ratio with diesel, results show biodiesel’s capacity to reduce emissions at 36% with a cost of $ 0.13 per kilogram of CO2 reduced, while e-fuels offer a potential reduction of 50% of emissions at a cost of $ 0.22 per kilogram of CO2 reduced. Battery-electric results for 50% deployment over all ton-miles highlight the value of future innovations in battery energy densities as scenarios assuming 800-mi range locomotives show an estimated emissions reduction of 46% with a cost of $ 0.06 per kilogram of CO2 reduced, compared with 16% emissions reduction at a cost of $ 0.11 per kilogram of CO2 reduced for 400-mi range locomotives. The NUFRIEND framework provides a systematic method for comparing different alternative energy technologies and identifying potential challenges and benefits in their future deployments.]]></description>
      <pubDate>Mon, 22 May 2023 16:36:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2173516</guid>
    </item>
    <item>
      <title>An Energy Management Strategy for Multi-energy Drive Systems Based on Dynamic Programming</title>
      <link>https://trid.trb.org/View/2113790</link>
      <description><![CDATA[A multi-energy drive system (MEDS) uses a variety of power sources for energy supply, which has the advantages of flexible configuration, economic and environmental protection, and has been widely concerned and applied in rail transit. Energy management strategy is an important factor in the design of multi-energy drive system. A good energy management strategy is the guarantee to optimize the energy distribution of each power source in the system, improve the system efficiency, and reduce energy consumption and emissions. In this paper, the dynamic programming algorithm is used to optimize the diesel fuel consumption based on the known demand power curve. Compared with the rule-based algorithm before improvement, the diesel consumption is reduced by 7.7% in 785 s simulation period, which shows that the optimization effect is better.]]></description>
      <pubDate>Fri, 21 Apr 2023 09:51:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2113790</guid>
    </item>
    <item>
      <title>Dual-Mode DC/DC Converter for Multi-energy Drive System</title>
      <link>https://trid.trb.org/View/2113782</link>
      <description><![CDATA[With the reduction of fossil energy and the emission limitation of relevant laws and regulations, the demand for new power vehicles is increasing. According to this, diesel electric hybrid vehicle is the transition stage from traditional energy driven to electric driven, which has important research significance. Since the energy storage battery pack is used as auxiliary power, the diesel generator is still the main power source of diesel electric hybrid vehicle, so the control stability of AC/DC converter between diesel generator and intermediate DC bus should be guaranteed first. Based on this, this paper proposes a dual-mode switching control method for Bi-directional DC/DC converter. At the same time, in order to ensure the stability of battery charging and discharging, this paper adopts a control method to improve the PI controller by adding a load current loop, and verifies the stability of the control system through simulation.]]></description>
      <pubDate>Fri, 21 Apr 2023 09:51:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2113782</guid>
    </item>
    <item>
      <title>Multi-mode Control of Variable-Speed Generator Set in Multi-energy Drive System</title>
      <link>https://trid.trb.org/View/2113739</link>
      <description><![CDATA[In order to reduce fuel consumption and emissions, a multi-modal control for variable-speed generator sets in isolated multi-energy drive systems is studied. However, due to the lag of the dynamic performance of the diesel engine, its speed cannot be adjusted quickly. During the sudden increase of load power, the power required by the load cannot be provided, and the system power quality will decrease and the DC side voltage will be unstable. A multi-energy drive system based on a variable-speed generator set with battery pack can improve this dynamic performance, improve power quality, and reduce fuel consumption and emissions. In addition, this article simulates the operation of a single generator system and a multi-energy drive system with energy storage battery under different conditions by establishing models such as battery packs, diesel generator sets, DC/DC converters and PWM converters. Circumstances, the feasibility of the system is verified based on theory.]]></description>
      <pubDate>Fri, 21 Apr 2023 09:51:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2113739</guid>
    </item>
    <item>
      <title>An Estimation Method for Replacement Cost of Multi-energy Drive System</title>
      <link>https://trid.trb.org/View/2113735</link>
      <description><![CDATA[The replacement cost accounts for a large proportion of the economic cost in the whole life cycle of shunting locomotive. Therefore, accurate calculation of the replacement cost of multi-energy drive system plays an important role in optimizing the configuration and reducing the economic cost. The diesel generator set can basically meet the energy supply demand of a fixed number of years, therefore, the replacement times in the 32 years’ life cycle are generally two, and the core problem is to calculate the replacement cost of the power battery pack. In this paper, a V-shaped closed-loop counting method is used. On the premise of knowing the SOC (state of charge) curve of the battery, a model is established to calculate the DOD (depth of discharge) of the power battery pack, so as to obtain the replacement times of the power battery pack. Combined with the initial purchase cost, the replacement cost of the energy storage system is calculated. The results show that under the existing configuration, it is 6 times of the initial purchase cost.]]></description>
      <pubDate>Fri, 21 Apr 2023 09:51:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2113735</guid>
    </item>
    <item>
      <title>Analysis of hydrogen-powered propulsion system alternatives for diesel-electric regional trains</title>
      <link>https://trid.trb.org/View/2001995</link>
      <description><![CDATA[Non-electrified regional railway lines with typically employed diesel-electric multiple units require alternative propulsion systems to meet increasingly strict emissions regulations. With the aim to identify an optimal alternative to conventional diesel traction, this paper presents a model-based assessment of hydrogen-powered propulsion systems with an internal combustion engine or fuel cells as the prime mover, combined with different energy storage system configurations, based on lithium-ion batteries and/or double-layer capacitors. The analysis encompasses technology identification, design, modelling and assessment of alternative powertrains, explicitly considering case-related constraints imposed by the infrastructure, technical and operational requirements. Using a regional railway network in the Netherlands as a case, the authors investigate the possibilities in converting a conventional benchmark vehicle and provide the railway undertaking and decision-makers with valuable input for planning of future rolling stock investments. The results indicate the highest fuel-saving potential for fuel cell-based hybrid propulsion systems with lithium-ion battery or a hybrid energy storage system that combines both energy storage system technologies. The two configurations also demonstrate the highest reduction of greenhouse gas emissions compared to the benchmark diesel-driven vehicle, by about 25% for hydrogen produced by steam methane reforming, and about 19% for hydrogen obtained from electrolysis of water with grey electricity.]]></description>
      <pubDate>Tue, 20 Sep 2022 12:02:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2001995</guid>
    </item>
    <item>
      <title>Li-Ion Battery-Based Hybrid Diesel-Electric Railway Vehicle: In-Depth Life Cycle Cost Analysis</title>
      <link>https://trid.trb.org/View/1987468</link>
      <description><![CDATA[In this study, the life cycle costs of railway projects involving hybrid diesel-electric vehicles are analysed. Specifically, the analysis focuses on the comparison of 3 lithium-ion battery technologies (NMC, LTO and LFP) and 8 energy management strategies (including rule-based and optimization-based strategies). In order to develop this analysis, a methodology that returns the life cycle cost of each proposed case is presented. The methodology includes the optimization of the diesel generator and lithium-ion battery sizing. A scenario based on a real railway line is introduced, and the obtained results are compared to a traditional diesel-electric railway vehicle to develop a techno-economical discussion. The best lithium-ion battery technologies are found to be LTO and NMC, and the most appropriated strategy a state-machine controller optimised by a genetic algorithm approach. The best case obtains a life cycle cost reduction of the 4.0% and diesel savings of the 13.7% compared to a traditional diesel-electric railway vehicle. The proposed analysis is claimed to be potentially helpful for the cost-optimal design and operation definition of powertrains for hybrid railway vehicles.]]></description>
      <pubDate>Thu, 21 Jul 2022 11:42:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/1987468</guid>
    </item>
    <item>
      <title>Impact of Driving Style on the Exhaust Emission of a Diesel Multiple Unit</title>
      <link>https://trid.trb.org/View/1752019</link>
      <description><![CDATA[This paper considers aspects regarding exhaust emissions from vehicles, the reduction of which is one of the main trends of current worldwide development efforts. These efforts resulted in numerous legal tools being created to tackle the problem of toxic gas emissions and global warming. These tools include emission limits and type approval procedures. Such norms for rail vehicles are simplistic and fail to provide a reliable method of assessing the real exhaust emission from rail vehicles operating on the tracks. Hence, PEMS (portable emission measurement system) type apparatus was used to perform measurements of exhaust emissions of a diesel multiple unit designed for short–mid range passenger transport in real operating conditions. The vehicle tested belonged to a widely and commonly used group of passenger vehicles, and the testing methods were similar to current RDE (real driving emissions) test requirements for road vehicles. The selected vehicle was powered by an internal combustion engine in which ecological and economic properties depend on the operating ranges and parameters used. These types of train lines are characterized by frequent stops at stations, which confirms the need to investigate this subject. The vehicle exhaust emissions were measured for different driving styles, regular driving style typical for the driver and a drive more closely in line with the concepts of eco-driving, with reduced maximum acceleration values. Since most previous studies on the eco-driving principles used road vehicles for testing, this resulted in a gap in knowledge in this field regarding rail vehicles. The aim of the paper is to assess the impact of the choice of driving style on the exhaust emission values of a selected passenger rail vehicle.]]></description>
      <pubDate>Wed, 03 Feb 2021 15:00:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1752019</guid>
    </item>
    <item>
      <title>Steady State</title>
      <link>https://trid.trb.org/View/1736623</link>
      <description><![CDATA[Railinc conducts an annual analysis of the North American diesel-electric locomotive fleet; this article reports this year's findings. The total size of the fleet at the end of 2019 was found to be 39,125, a decrease of 393 units from 2018. The average age of the fleet was found to be 27.3 years, an increase of .7 years from the previous year. About 244 new locomotives joined the North American fleet in 2019, marking the third consecutive year that the fleet added fewer than 300 units. While DC traction locomotives make up 64% of the North American fleet, more AC units continue to join the fleet. The share of AC traction locomotives has increased by 10 percentage points since 2009, and AC locomotives have dominated among additions in the last 12 years. As has been the case for the past nine years, six-axle locomotives make up 69% of the North American fleet. Road units (locomotives with six axles and a horsepower rating of 2,500 or higher) comprise 67% of the fleet in North America, while switchers (locomotives with four axles and a horsepower rating of 2,500 or less) make up about 22%.]]></description>
      <pubDate>Tue, 29 Sep 2020 11:05:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1736623</guid>
    </item>
    <item>
      <title>Component sizing and intelligent energy management of a heavy hybrid electric vehicle based on a real drive cycle</title>
      <link>https://trid.trb.org/View/1624137</link>
      <description><![CDATA[In this paper, hybridizing a heavy vehicle is developed. A switcher locomotive is considered for hybridization. Due to their low operational speed, the switcher locomotives require much lower power when compared to other types of locomotives. Besides, switcher locomotives have higher loss of energy due to their frequent starting and stopping. Hybrid-powered transit vehicles are considered to be excellent replacements for ordinary transit vehicles, since hybrid powered vehicles are equipped with more than one traction power sources. Therefore, a switcher locomotive’s driving cycle is derived from the measured field data and used to calculate and design the hybrid vehicle’s components. A “fuzzy controller” is used to plan a suitable controller for the designed hybrid locomotive. Comparisons show a substantial decrease, both in the fuel consumption and the pollutions of the designed hybrid switcher locomotive versus the conventional diesel-electric locomotives.]]></description>
      <pubDate>Fri, 31 May 2019 09:35:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1624137</guid>
    </item>
    <item>
      <title>Application and benchmarking of a direct method to optimize the fuel consumption of a diesel electric locomotive</title>
      <link>https://trid.trb.org/View/1624075</link>
      <description><![CDATA[This paper addresses the optimal control of a long-haul passenger train to deliver minimum-fuel operations. Contrary to the common Pontryagin minimum principle approach in railroad-related literature, this work addresses this optimal control problem with a direct method of optimization, the use of which is still marginal in this field. The implementation of a particular direct method based on the Euler collocation scheme and its transcription into a nonlinear problem are described in detail. In this paper, this optimization technique is benchmarked with well-known optimization methods in the literature, namely dynamic programming and the Pontryagin minimum principle, by simulating a real route. The results showed that the direct methods are on the same level of optimality compared with other algorithms while requiring reduced computational time and memory and being able to handle very complex dynamic systems. The performance of the direct method is also compared to the real trajectory followed by the train operator and exhibits up to 20% of fuel saving in the example route.]]></description>
      <pubDate>Fri, 31 May 2019 09:35:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1624075</guid>
    </item>
    <item>
      <title>High Speed Rail Planning, Policy, and Engineering, Volume I: Overview of Development and Engineering Requirements</title>
      <link>https://trid.trb.org/View/1472427</link>
      <description><![CDATA[This book investigates the potential productivity and profitability of high-speed passenger rail lines. It also examines the political factors influencing funding and location of high-speed rail. After an introduction in chapter 1, the second chapter looks at politics in the United States. Chapter 3 considers recent high-speed rail accomplishments, which include speed records for trains with steel wheels operating on steel rail. The history of high-speed rail, especially in the United States, is discussed in chapter 4. Chapter 5 covers development of high-speed rail systems on existing routes. Chapter 6 explores possible configurations of right-of-way and terminals. The gauge, construction, and maintenance of track are explained in chapter 7, including track on curves. Chapter 8 looks at equipment parameters, while chapter 9 takes up operating parameters. Chapter 10 explains the relationship between cost and speed. The issue of security in all its facets is reviewed in chapter 11. Chapters 12, 13, and 14 evaluate several alternative high-speed rail systems, which include true high-speed systems, hybrid systems, and blended systems. Market factors, among which are traffic potential and environmental factors, are surveyed in chapter 15. Possible routes for practical systems are discussed in chapter 16. Chapter 17 looks at motive power. Chapter 18 peruses trains with both passenger and freight cars. Finally, chapter 19 goes over financial considerations.]]></description>
      <pubDate>Thu, 22 Mar 2018 12:03:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1472427</guid>
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