Optimal Operating Strategy for Hybrid Railway Vehicles based on a Sensitivity Analysis

2014 ◽  
Vol 47 (3) ◽  
pp. 942-947
Author(s):  
Maik Leska ◽  
Robert Prabel ◽  
Harald Aschemann ◽  
Andreas Rauh
2017 ◽  
Vol 27 (2) ◽  
pp. 323-336
Author(s):  
Maik Leska ◽  
Harald Aschemann ◽  
Michael Melzer ◽  
Michael Meinert

Abstract In contrast to road-based traffic, the track as well as the corresponding duty cycle for railways are known beforehand, which represents a great advantage during the development of operating strategies for hybrid vehicles. Hence the benefits of hybrid vehicles regarding the fuel consumption can be exploited by means of an off-line optimisation. In this article, the fuel-optimal operating strategy is calculated for one specified track using two hybrid railway vehicles with different kinds of energy storage systems: on the one hand, a lithium-ion battery (high-energy storage) and, on the other, a double layer capacitor (high-power storage). For this purpose, control-oriented simulation models are developed for each architecture addressing the main effects contributing to the longitudinal dynamics of the power train. Based on these simulation models, the fuel-optimal operating strategy is calculated by two different approaches: Bellman’s dynamic programming, a wellknown approach in this field, and an innovative sensitivity-based optimisation.


2014 ◽  
Vol 625 ◽  
pp. 422-425
Author(s):  
Ruth Yong ◽  
Abdulhalim Shah Maulud ◽  
Humbul Suleman

Amine based solvents are extensively being used for post combustion carbon capture through absorption. Each solvent has its associated benefits and drawbacks. In order to overcome their drawbacks, a number of mixed amine streams have been used. However, this amalgamation step is usually overshadowed by process optimization issues and cost limitations. In this study, Monoethanolamine (MEA) – Methyldiethanolamine (MDEA) is used as the mixed amine-based solvent for removal of carbon dioxide. A simulation model of CO2removal is developed using Aspen HYSIS to optimize the process. Subsequently, an economic analysis is constructed to evaluate the operating expenditure (OPEX) and capital expenditure (CAPEX) based on the simulation model, followed by sensitivity analysis. It is found that 25 wt% MDEA and 15 wt% MEA is the optimal operating condition that achieve the minimal total cost. Sensitivity analysis reveals that utilities cost affects the total cost significantly, followed by CAPEX. However, the effect of raw material costs on total cost is negligible.


Author(s):  
Sönke Kraft ◽  
Daniel Lüdicke

For the reliable simulation-based fatigue design of railway vehicles, the operation conditions and resulting loads over the lifespan of the vehicle have to be considered. After introducing the relevant fatigue loads on the vehicle and the methods for modelling the fatigue damage, this work aims at analysing the influence of the operating conditions and loads on the damage using sensitivity analysis. Two approaches are studied: the variance-based sensitivity analysis of the loads acting on the car body and the influence of different operating conditions using statistical values per track section. The loads are obtained from multi-body simulations and the damage is estimated using both physical FE-models and meta-models. The performances of linear regression models and polynomial chaos models are evaluated. The proposed sensitivity analysis is applied to the highspeed train being developed in the Next Generation Train (NGT) project at DLR and will serve as a basis for the virtual design and reliability analysis.


2000 ◽  
Author(s):  
Jeppe Grue ◽  
Jens Andersen ◽  
Niels From ◽  
Inger Bach

Abstract In Denmark power generation is extensively based on small combined heat and power plants, which produce electric power and district heating. This work will focus on the small plants around 1 MW in size, which are often unmanned and operating completely automatically. The objective of this work is to formulate a method which can be used to determine the optimal operating strategy for a CHP plant, and that this strategy must be fully automated. The contribution margin of the plant is used as the objective function for the optimization. Finally the method is tested on a small CHP plant, which is a gas engine producing 1.34 MW electrical power and 1.6 MJ/s district heating. The methods, which are developed, can be used in general for the evaluation and optimization of automated strategies for the operation of small-unmanned CHP plants. The strong feature of the method is that it sets an ultimate target that is the best possible one to obtain with a view to any strategy. This provides a basis for the evaluation and optimization of the actual strategy.


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