Improving energy-efficient train operation in urban railways: employing the variation of regenerative energy recovery rate

2017 ◽  
Vol 11 (6) ◽  
pp. 349-357 ◽  
Author(s):  
Saeed Ahmadi ◽  
Ali Dastfan ◽  
Mohsen Assili
Keyword(s):  
Energy Efficient ◽  
Recovery Rate ◽  
Energy Recovery ◽  
Train Operation ◽  
Regenerative Energy

Cost-benefit analysis for regenerative energy storage in metro

2017 ◽  
Vol 11 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Xiang Li ◽  
Ziyou Gao
Keyword(s):  
Energy Storage ◽  
Recovery Rate ◽  
Energy Recovery ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Maintenance Cost ◽  
Benefit Analysis ◽  
Content Type ◽  
Storage Devices ◽  
Regenerative Energy

Purpose Regenerative braking is an efficient energy saving technology in urban rail system, in which the recovery energy from braking trains is collected by some equipments and released to accelerating trains when needed. However, the high cost and low lifetime of storage devices prevent the widespread use of this technology. The purpose of this paper is to conduct thorough cost-benefit analysis to facilitate China’s urban rail companies to make decisions on the use of such technology. Design/methodology/approach To evaluate the benefit from regenerative energy storage, the authors formulate an improved integrated scheduling and speed control model to calculate the net energy consumption associated with different energy recovery rates and then define the benefit as the amount of energy saving arising from the usage of storage equipments. With the frequent charge/discharge operations on storage equipments, the energy recovery rate generally decreases which lowers the benefit, but the maintenance cost increases. By trading-off benefit and cost, the authors derive the optimal scrapping time, the maximum profit and the profitability condition for storage devices. Findings Simulation studies based on the Beijing Metro Yizhuang Line of China are given. The results show that compared with the current timetable and speed profile, the integrated scheduling and speed control approach with energy recovery rate of 0.5 can reduce the net energy consumption by 12.69 per cent; the net energy consumption can be well approximated as a linear function of energy recovery rate; and the maximum profit and the optimal scrapping time on regenerative energy storage devices are both positively related to the electricity price. The allowance proportion and the number of service trains such that busy lines with higher electricity price or allowance proportion have advantages to use the regenerative energy storage devices. Research limitations/implications In this work, a linear energy recovery rate and a linear maintenance cost are used in the cost-benefit analysis process. In future research, the more accurate expressions on energy recovery rate and maintenance cost should be considered if more data on recovery rate and maintenance cost can be gathered. Originality/value The main values of this paper are to develop the integrated optimization approaches for train scheduling and speed control and, on this basis, make thorough cost-benefit analysis for regenerative energy storage to improve the operations management of urban rail transit.

scholarly journals A biomechanical study of load carriage by two paired subjects in response to increased load mass

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillaume Fumery ◽  
Nicolas A. Turpin ◽  
Laetitia Claverie ◽  
Vincent Fourcassié ◽  
Pierre Moretto
Keyword(s):  
Recovery Rate ◽  
Energy Recovery ◽  
Mechanical Energy ◽  
Center Of Mass ◽  
Step Length ◽  
Biomechanical Study ◽  
Load Carriage ◽  
Joint Torque ◽  
Total Mechanical Energy ◽  
Load Mass

AbstractThe biomechanics of load carriage has been studied extensively with regards to single individuals, yet not so much with regards to collective transport. We investigated the biomechanics of walking in 10 paired individuals carrying a load that represented 20%, 30%, or 40% of the aggregated body-masses. We computed the energy recovery rate at the center of mass of the system consisting of the two individuals plus the carried load in order to test to what extent the pendulum-like behavior and the economy of the gait were affected. Joint torque was also computed to investigate the intra- and inter-subject strategies occurring in response to this. The ability of the subjects to move the whole system like a pendulum appeared rendered obvious through shortened step length and lowered vertical displacements at the center of mass of the system, while energy recovery rate and total mechanical energy remained constant. In parallel, an asymmetry of joint moment vertical amplitude and coupling among individuals in all pairs suggested the emergence of a leader/follower schema. Beyond the 30% threshold of increased load mass, the constraints at the joint level were balanced among individuals leading to a degraded pendulum-like behavior.

An improved brain storm optimisation algorithm for energy-efficient train operation problem

2021 ◽  
Vol 17 (4) ◽  
pp. 236
Author(s):  
Boyang Qu ◽  
Qian Zhou ◽  
Yongsheng Zhu ◽  
Jing Liang ◽  
Caitong Yue ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Optimisation Algorithm ◽  
Train Operation

scholarly journals Case study of stationary energy storage device in a 3 kV DC traction system

2018 ◽  
Vol 180 ◽  
pp. 02005 ◽  
Author(s):  
Włodzimierz Jefimowski ◽  
Anatolii Nikitenko
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Energy Utilization ◽  
Storage Device ◽  
Location Selection ◽  
Train Operation ◽  
Traction Substations ◽  
Traction System ◽  
Regenerative Energy

The paper presents the results of economic study of energy storage system (ESS) implemented in 3 kV DC power supply system. Two conceptions of ESS have been investigated: ESS with supercapacitor (SC) and hybrid ESS (HESS) with SC and LFP battery. The investigated locations of energy storage systems are considered among existing traction substations in two railway lines with different density of train operation. The considered aims of energy storage system implementation are decreasing of energy consumption by maximum regenerative energy utilization and reduction of peak 15- min power demand of traction substation. The paper presents a method of regenerative power estimation depending on the location of the considered ESS implementation point. Also the method of optimal location selection of ESS in terms of minimization of Simple Payback Time (SPBT) of investment is presented. Besides the influence of initial cost value as well as energy price on the SPBT value are investigated. The results are compared between two railway lines with different number of trains operating.

scholarly journals A Sparse Optimization Approach for Energy-Efficient Timetabling in Metro Railway Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Ziyan Luo ◽  
Xiaoyu Li ◽  
Naihua Xiu
Keyword(s):  
Optimization Model ◽  
Energy Efficient ◽  
Convex Relaxation ◽  
Sparse Optimization ◽  
Computational Time ◽  
Optimization Approach ◽  
Railway Systems ◽  
Alternating Direction ◽  
Np Hard Problem ◽  
Regenerative Energy

In this paper, we propose a sparse optimization approach to maximize the utilization of regenerative energy produced by braking trains for energy-efficient timetabling in metro railway systems. By introducing the cardinality function and the square of the Euclidean norm function as the objective function, the resulting sparse optimization model can characterize the utilization of the regenerative energy appropriately. A two-stage alternating direction method of multipliers is designed to efficiently solve the convex relaxation counterpart of the original NP-hard problem and then to produce an energy-efficient timetable of trains. The resulting approach is applied to Beijing Metro Yizhuang Line with different instances of service for case study. Comparison with the existing two-step linear program approach is also conducted which illustrates the effectiveness of our proposed sparse optimization model in terms of the energy saving rate and the efficiency of our numerical optimization algorithm in terms of computational time.

scholarly journals Shrinking horizon parametrized predictive control with application to energy-efficient train operation

Automatica ◽  
2020 ◽  
Vol 112 ◽  
pp. 108635
Author(s):  
Hafsa Farooqi ◽  
Lorenzo Fagiano ◽  
Patrizio Colaneri ◽  
Davide Barlini
Keyword(s):  
Predictive Control ◽  
Energy Efficient ◽  
Train Operation

Energy-Efficient Train Operation with Given Time

ICTE 2011 ◽  
2011 ◽  
Author(s):  
Yan Zhang ◽  
Zhengbin Wang ◽  
Qiaomei Tang ◽  
Zilan Wang
Keyword(s):  
Energy Efficient ◽  
Train Operation
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