scholarly journals Flywheel vs. Supercapacitor as Wayside Energy Storage for Electric Rail Transit Systems

Inventions ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 62
Author(s):  
Mahdiyeh Khodaparastan ◽  
Ahmed Mohamed
Keyword(s):  
Energy Storage ◽  
Energy Saving ◽  
Voltage Regulation ◽  
Appropriate Technology ◽  
Rail Transit ◽  
Peak Demand ◽  
Transit System ◽  
Transit Systems ◽  
Industrial Sectors ◽  
Demand Reduction

Energy storage technologies are developing rapidly, and their application in different industrial sectors is increasing considerably. Electric rail transit systems use energy storage for different applications, including peak demand reduction, voltage regulation, and energy saving through recuperating regenerative braking energy. In this paper, a comprehensive review of supercapacitors and flywheels is presented. Both are compared based on their general characteristics and performances, with a focus on their roles in electric transit systems when used for energy saving, peak demand reduction, and voltage regulation. A cost analysis is also included to provide initial guidelines on the selection of the appropriate technology for a given transit system.

scholarly journals A Dual-Stage Modeling and Optimization Framework for Wayside Energy Storage in Electric Rail Transit Systems

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1614
Author(s):  
Oindrilla Dutta ◽  
Mahmoud Saleh ◽  
Mahdiyeh Khodaparastan ◽  
Ahmed Mohamed
Keyword(s):  
Energy Storage ◽  
Search Space ◽  
Voltage Regulation ◽  
Maximum Energy ◽  
Transit System ◽  
Transit Systems ◽  
Modeling And Optimization ◽  
Optimization Framework ◽  
Dual Stage ◽  
Stage Modeling

In this paper, a dual-stage modeling and optimization framework has been developed to obtain an optimal combination and size of wayside energy storage systems (WESSs) for application in DC rail transportation. Energy storage technologies may consist of a standalone battery, a standalone supercapacitor, a standalone flywheel, or a combination of these. Results from the dual-stage modeling and optimization process have been utilized for deducing an application-specific composition of type and size of the WESSs. These applications consist of different percentages of energy saving due to regenerative braking, voltage regulation, peak demand reduction, estimated payback period, and system resiliency. In the first stage, sizes of the ESSs have been estimated using developed detailed mathematical models, and optimized using the Genetic Algorithm (GA). In the second stage, the respective sizes of ESSs are simulated by developing an all-inclusive model of the transit system, ESS and ESS management system (EMS) in MATLAB/Simulink. The mathematical modeling provides initial recommendations for the sizes from a large search space. However, the dynamic simulation contributes to the optimization by highlighting the transit system constraints and practical limitations of ESSs, which impose bounds on the maximum energy that can be captured from decelerating trains.

Finite Element Analysis of Rail-End Bolt Hole and Fillet Stress on Bolted Rail Joints

2017 ◽  
Vol 2607 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Kaijun Zhu ◽  
Yu Qian ◽  
J. Riley Edwards ◽  
Bassem O. Andrawes
Keyword(s):  
Finite Element ◽  
Vertical Displacement ◽  
Rail Transit ◽  
Rail Transportation ◽  
Element Analysis ◽  
Transit System ◽  
Transit Systems ◽  
Service Failures ◽  
The University ◽  
Continuously Welded Rail

A rail joint typically is one of the weakest elements of a track superstructure, primarily because of discontinuities in its geometric and mechanical properties and the high-impact loads induced by these discontinuities. The development of continuously welded rail has significantly reduced the number of rail joints, but many bolted joints remain installed in rail transit systems. Because of the unique loading environment of a rail transit system (especially high-frequency, high-repetition loads), defects related to bolted rail joints (e.g., joint bar failures, bolt hole cracks, and cracks in the upper fillet) continue to cause service failures and can pose derailment risks. Recent research in the Rail Transportation and Engineering Center at the University of Illinois at Urbana–Champaign has focused on investigating crack initiation in the bolt hole and fillet areas of bolted rail joints. Stress distribution was investigated at the rail-end bolt hole and upper fillet areas of standard, longer, and thicker joint bars under static loading conditions. Numerical simulations were organized into a comprehensive parametric analysis performed with finite element modeling. Preliminary results indicated that the longer joint bar performed similarly to the standard joint bar but the thicker joint bar reduced rail vertical displacement and rail upper fillet stresses compared with the standard joint bar. However, the thicker joint bar also may generate higher stresses at the rail-end bolt hole. Additionally, joint bar performance was dependent on the rail profile and bolt hole location.

Assessing Transit Changes in Columbus, Ohio, and Sacramento, California

2005 ◽  
Vol 1930 (1) ◽  
pp. 62-67 ◽  
Author(s):  
John Schumann
Keyword(s):  
Federal Funding ◽  
Light Rail ◽  
Rail Transit ◽  
Transit System ◽  
Transit Systems ◽  
Bus Transit ◽  
The Past ◽  
Voter Approval ◽  
Capital Funding ◽  
Bus Service

This paper compares the changes experienced by transit systems in two state capitals of similar size: Columbus, Ohio, and Sacramento, California. Over the past two decades, Sacramento added a light rail transit (LRT) starter line and experienced significant ridership growth on its multimodal rail and bus system, while Columbus remained all-bus and experienced a decline in patronage. Reasons underlying the divergent performances of these two systems are analyzed and discussed. It is concluded that, in Sacramento, willing political leadership took good advantage of a one-time opportunity for federal funding to build an LRT starter line; that adding LRT made transit more visible and effective and encouraged voter approval of additional local operating and capital funding; and that all of this resulted in a synergy that attracted more riders to the total LRT and bus transit system and led to extension of the rail system to a third corridor in 2003. Although planning for LRT was begun in Columbus during these same years, a serious interruption in the flow of local funds hampered transit development, required cuts in bus service, and prevented development of that region's planned LRT line. Columbus currently has an LRT project in preliminary engineering, and recent reports suggest a consensus to proceed may be emerging.

The Hangover: Assessing Impact of Major Service Interruptions on Urban Rail Transit Ridership

2017 ◽  
Vol 2648 (1) ◽  
pp. 79-85
Author(s):  
Julene Paul ◽  
Michael J. Smart
Keyword(s):  
New York ◽  
Urban Areas ◽  
Hurricane Sandy ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Transit System ◽  
Transit Systems ◽  
Service Interruptions ◽  
Transit Ridership ◽  
Transit Agencies

Driven by several factors, transit ridership has increased dramatically in some major U.S. urban areas over the past several years. Developing accurate econometric models of system ridership growth will help transit agencies plan for future capacity. As major weather events and maintenance issues can affect transit systems and have large impacts on the trajectory of ridership growth, this study examined the effect of major and minor service interruptions on the PATH heavy rail transit system in northern New Jersey and New York City. The study, which used PATH ridership data as well as data on weather, economic conditions, and fares for both PATH and competing services, concluded that Hurricane Sandy likely dampened ridership gains. Other major service interruptions, which lasted only hours or days, had little effect on long-term ridership growth. Suggestions for further study of service interruptions, especially in the face of climate change and resiliency issues in coastal regions, are presented.

scholarly journals Battery energy storage system (BESS) design for peak demand reduction, energy arbitrage and grid ancillary services

2020 ◽  
Vol 11 (1) ◽  
pp. 398
Author(s):  
Wan Syakirah Wan Abdullah ◽  
Miszaina Osman ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Renuga Verayiah
Keyword(s):  
Energy Storage ◽  
Power Systems ◽  
Storage System ◽  
Energy Storage System ◽  
Battery Energy Storage System ◽  
Peak Demand ◽  
Battery Energy Storage ◽  
Demand Reduction ◽  
The Stability ◽  
Battery Energy

<span style="font-size: 9pt; font-family: 'Times New Roman', serif;">Renewable Energy (RE) penetration is a new phenomenon in power systems. In the advent of high penetration of RE in the systems, several issues have to be addressed especially when it involves the stability and flexibility of the power systems. Battery Energy Storage System (BESS) has gained popularity due to its capability to store energy and to serve multiple purposes in solving various power system concerns. Additionally, several BESS can be combined to operate as Virtual Power Plant (VPP). This study will involve the design and implementation of BESS for five potential customer sites for the demonstration project and to be possibly integrated into one VPP system. The study is expected to demonstrate bill savings to the customers with BESS due to peak demand reduction and energy arbitrage savings.</span><table class="MsoNormalTable" style="width: 444.85pt; border-collapse: collapse; border: none; mso-border-alt: solid windowtext .5pt; mso-yfti-tbllook: 1184; mso-padding-alt: 0in 5.4pt 0in 5.4pt; mso-border-insideh: .5pt solid windowtext; mso-border-insidev: .5pt solid windowtext;" width="593" border="1" cellspacing="0" cellpadding="0"><tbody><tr style="mso-yfti-irow: 0; mso-yfti-firstrow: yes; mso-yfti-lastrow: yes; height: 63.4pt;"><td style="width: 290.6pt; border: none; border-top: solid windowtext 1.0pt; mso-border-top-alt: solid windowtext .5pt; padding: 0in 5.4pt 0in 5.4pt; height: 63.4pt;" valign="top" width="387"><p class="MsoNormal" style="margin-top: 6.0pt; text-align: justify;"><span style="font-size: 9.0pt; color: black; mso-bidi-font-style: italic;">Renewable Energy (RE) penetration is a new phenomenon in power systems. In the advent of high penetration of RE in the systems, several issues have to be addressed especially when it involves the stability and flexibility of the power systems. Battery Energy Storage System (BESS) has gained popularity due to its capability to store energy and to serve multiple purposes in solving various power system concerns. Additionally, several BESS can be combined to operate as Virtual Power Plant (VPP). This study will involve the design and implementation of BESS for five potential customer sites for the demonstration project and to be possibly integrated into one VPP system. The study is expected to demonstrate bill savings to the customers with BESS due to peak demand reduction and energy arbitrage savings.</span></p></td></tr></tbody></table>

Sign in / Sign up

Export Citation Format

Share Document