Analysis, Evaluation and Simulation of Railway Diesel-Electric and Hybrid Units as Distributed Energy Resources

The objective of this paper involves the analysis, identification and evaluation of different possibilities offered by technology for the improvement and the management of the use of energy and hybridization in railways: On board generation, demand response and energy storage, both in traction and auxiliary loads, considering the aggregation of resources and its stochastic nature. The paper takes into account the importance of efficient use of energy in railways, both currently (trains in service, prototypes) and in the future, considering the trends driven by energy policy scenarios (2030–2050) that will affect service and operation of units during their lifetime. A new activity has been considered that will be relevant in the future in the framework of a new electricity supply paradigm: Smart-Grids. According to this paradigm, the interaction of the Electric Power System and the Railway Supply System (somehow embedded in the Power System) will bring new opportunities for the collaboration of these two systems to perform, in a wise economic fashion, a better and more reliable operation of the complete energy system. The paper is focused on a mixed profile with low-medium traffic (passenger and freight): The first part of the route is electrified (3 kV DC catenary) whereas the second part is not electrified. Results justify that complex policies and objectives bring an opportunity to make cost-effective the hybridization of railway units, especially in low/medium traffic lines, which improves their social and economic sustainability.Authors are very grateful to the information, data and technical discussions provided by Patentes Talgo S.A. (Spain). This work was supported by the Ministerio de Ciencia, Innovación y Universidades (Spanish Government) under research project ENE-2016-78509-C3-2-P; Ministerio de Educación (Spanish Government) under grant FPU17/02753 and especially EU FEDER funds. This work was supported by the Ministerio de Ciencia, Innovación y Universidades, Spanish Government) under research project ENE-2016-78509-C3-2-P; Ministerio de Educación through grant FPU17/02753 and EU FEDER funds. Authors have also received funds from these grants for covering the costs to publish in open access

Assessment and simulation of the responsive demand potential in end-user facilities: application to a university customer

Many problems have appeared with the practical implementation of restructured electrical business in the U.S.and European Union such as lack of generation,network constraints,etc. A good example of these problems is the scarce participation of the demand in the electricity markets—energy,reserve,and other ancillary services—problems that could be solved through new de-mand responsive programs,aimed to replace the traditional demand side management programs in to voluntary demand partici-pation programs.A methodology for the generation of demand side bids and ofers in large customer facilities and a real application to a university customer is presented in this paper.The methodology is based on the knowledge of the physical processes involved in the electricity consumption and on the flexibility of there quired supply.The result of the methodology proposed is a set of demand packages that can be used to participate in different electricity markets,whose possibilities- in the market arena — will be explored in a consequent paper.This work was supported by the Ministerio de Ciencia y Tecnología of Spain through Research Project DPI2001-2779-C02-01

Technical and economical tools to assess customer demand response in the commercial sector

[EN] The authors present a methodology to evaluate and quantify the economic parameters (costs and benefits) attached to customer electricity consumption by analyzing the service provided by the different "pieces" of absorbed electricity. The first step of this methodology is to perform a process oriented market segmentation to identify segments according to their flexibility potential. After that, a procedure based on comprehensive simulations to identify and quantify the actual demand that can be managed in the short term is presented and, finally, the required economic analysis is performed. The methodology, which is demonstrated with some applications to the commercial sector, not only helps the customers to integrate in flexible distribution systems but also offers the necessary economical parameters for them to integrate in electricity markets. (C) 2009 Elsevier Ltd. All rights reserved.This research work has been possible with the support of the European Commission through EU-DEEP Project, and through the support of the Spanish Government (Ministerio de Educacion y Ciencia) under Reasearch Project ENE2007-67771-C02-01&02/CON and Red Electrica de Espana, S.A. (the Spanish System Operator) through the collaboration with the International Energy Agency Project on DSM.Álvarez, C.; Alcázar-Ortega, M.; Escrivá-Escrivá, G.; Gabaldón Marín, A. (2009). Technical and economical tools to assess customer demand response in the commercial sector. Energy Conversion and Management. 50(10):2605-2612. https://doi.org/10.1016/j.enconman.2009.06.002S26052612501

Energy efficiency in railways: energy storage and electric generation in diesel electric locomotives

Diesel-electric traction is a well known and established technology for railways operators,but this alternative has a considerable uncerainty for the future because electric traction has a considerable superiority. Besides,diesel-electric engines was teenergy when resistive braking isused This non-regenerative braking decreases the overall efficiency by lO-20%.With these premises it is important to develop new strategies to increase the energy efficiency of diesel-electric haulag. To reach a better efficiency,a locomotive with energy storage(battery,super-capacitors)is theoretically proposed.Besides,the possibility of using alower thermal engine(from other diesel locomotives out of use)with energy storage devices is considered too.This solution reduces diesel consumption and CO2 emissions while being economically viable.It supposes an efficient energy management because the diesel-electric locomotive could acts as a dispersed mobile generation(DMG)unit when working under electric overhead lines,and it can be used as a distributed resource for this specific electric power system.This work was supported by the Spanish Government (Ministerio de Ciencia e Innovacion) under Research Project ENE2007-67771-C02-02/CON. The authors are very grateful to the information, data and time tables supplied by ADIF (Administrador de Infraestructuras Ferroviarias, Spanish Railway Network Operator)

Approach to multivariable predictive control applications in residential HVAC direct load control

The purpose of this paper is to describe a new constrained multivariable predictive control strategy applied in Residential HVAC Direct Load Control. In this way, starting from a target load profile prefixed by the utility in order to achieve several objectives - economic, technical- and taking into account customer constraints - minimum “fort levels, HVAC limits- this control algorithm provides, in a multiobjective hework, the most suitable HVAC load control strategy to minimize the discrepancies between the controlled load curve and the predefined target load curve. The control system has a close-loop behavior with a proper and consistent treatment of modeling errors and other disturbances. It is allowed a dynamic modification of the target load me according to the real-time system behavior. In order to demonstrate its qualities widely, this control system has been applied to modify a real load curve profile under different operating conditions

Harmonic model of electronically controlled loads

The use of electronically controlled loads is the way used to improve the efficiency as well as the power factor of normal elec- tric loads, obtaining thus energy efficient loads. This electronic con- trol changes the load’s global behavior resulting in a strongly non- linear one, at this regards, the available models used to represent loads are not accurate enough, especially in the context of an iterative frequency domain harmonic penetration program/algorithm. In this article, we propose an extension of the crossed-frequency admittance matrix, in order to get a better representation of these electronic loads. The extension is done by adding another dimension to the matrix, the harmonic phase. The model is obtained using a programmable power source connected to a PC, and by means of an acquisition board, we measure voltage and intensity. Due to the large number of tests needed we have developed a software tool that auto- mates the process giving as result the load model. Therefore, the proposed model linearizes loads according to three variables: Amplitude, Frequency and Phase of the harmonic with regard to the fundamental

Energy efficiency in railways: energy storage and electric generation in diesel electric locomotives. Póster

Diesel-electric traction is a well known and established technology for railways operators,but this alternative has a considerable uncerainty for the future because electric traction has a considerable superiority. Besides,diesel-electric engines was teenergy when resistive braking isused This non-regenerative braking decreases the overall efficiency by lO-20%.With these premises it is important to develop new strategies to increase the energy efficiency of diesel-electric haulag. To reach a better efficiency,a locomotive with energy storage(battery,super-capacitors)is theoretically proposed.Besides,the possibility of using alower thermal engine(from other diesel locomotives out of use)with energy storage devices is considered too.This solution reduces diesel consumption and CO2 emissions while being economically viable.It supposes an efficient energy management because the diesel-electric locomotive could acts as a dispersed mobile generation(DMG)unit when working under electric overhead lines,and it can be used as a distributed resource for this specific electric power system

Classification, filtering, and identification of electrical customer load patterns through the use of self-organizing maps

Different methodologies are available for clustering purposes. The objective of this paper is to review the capacity of some of them and specifically to test the ability of self-organizing maps (SOMs) to filter, classify, and extract patterns from distributor, commercializer, or customer electrical demand databases. These market participants can achieve an interesting benefit through the knowledge of these patterns, for example, to evaluate the potential for distributed generation, energy efficiency, and demand-side response policies (market analysis). For simplicity, customer classification techniques usually used the historic load curves of each user. The first step in the methodology presented in this paper is anomalous data filtering: holidays, maintenance, and wrong measurements must be removed from the database. Subsequently, two different treatments (frequency and time domain) of demand data were tested to feed SOM maps and evaluate the advantages of each approach. Finally, the ability of SOM to classify new customers in different clusters is also examined. Both steps have been performed through a well-known technique: SOM maps. The results clearly show the suitability of this approach to improve data management and to easily find coherent clusters between electrical users, accounting for relevant information about weekend demand patterns.This work was supported by European Union Sixth Frame work Program under Project EU-DEEP SES6-CT-2003-503516.Paper no.TPWRS-00633-200

Electrical thermal storage modeling: a tool to valuate new opportunities and bids for residential users in a deregulated market

The purpose ofthis paper is to describe a useful tool for the initial analysis to assess the possibilities of residential Electric Thermal Storage (ETS), taking into account heat storage and cool storage devices. These load models are based on an energy balance between the indoor environment, the dwelling constructive parameters, the ETS device and the internal mass through a discrete statespace equation system. The main application of this load model has been oriented towards the simulation of ETS performance in order to evaluate the possibilities of Load Management in the new de-regulated structures of Electrical Power Systems. The proposed model has been implemented and validated for heat storage, using real data collected during the last years in residential areas to evaluate its accuracy and flexibility. Finally, a simulation case study is presented to show the possibilities of modifying the actual residential demand profile through a storage period re-scheduling proposed by the authors, taking into account the customer minimum comfort levels and avoiding program rejection.The work described in this paper is financially supported by the Ministerio de Ciencia y Tecnologia of Spain, through a research project (Ref. DP12001-2779-C02-01). The authors are very grateful to the Spanish company Gabarrón-Elnur S.A. for the generous cession of its commercial ETS appliances in order to test them and for its support to this research

An integrated tool for assessing the demand profile flexibility

The purpose of this paper is to describe an integrated tool whose aim is to assess the residential demand profile flexibility through the control of space conditioning loads, mainly air conditioner and heat pump appliances. This assessment has been divided into two principal tasks—an estimation of the controllable load and a selection of the optimum load control strategy according to a target profile and a set of prefixed constraints. The tool also provides the aggregated load behavior, allowing a comparison between different load strategies. This tool can be applied from the customer’s and the utility’s side. An application example to a real environment is also presented.This work was supported by the Ministerio de Ciencia y Tecnología of Spain through Research Project DPI2001- 2779-C02-01