Assessment of the worthwhileness of efficient driving in railway systems with high-receptivity power supplies

Eco-driving is one of the most important strategies for significantly reducing the energy consumption of railways with low investments. It consists of designing a way of driving a train to fulfil a target running time, consuming the minimum amount of energy. Most eco-driving energy savings come from the substitution of some braking periods with coasting periods. Nowadays, modern trains can use regenerative braking to recover the kinetic energy during deceleration phases. Therefore, if the receptivity of the railway system to regenerate energy is high, a question arises: is it worth designing eco-driving speed profiles? This paper assesses the energy benefits that eco-driving can provide in different scenarios to answer this question. Eco-driving is obtained by means of a multi-objective particle swarm optimization algorithm, combined with a detailed train simulator, to obtain realistic results. Eco-driving speed profiles are compared with a standard driving that performs the same running time. Real data from Spanish high-speed lines have been used to analyze the results in two case studies. Stretches fed by 1 × 25 kV and 2 × 25 kV AC power supply systems have been considered, as they present high receptivity to regenerate energy. Furthermore, the variations of the two most important factors that affect the regenerative energy usage have been studied: train motors efficiency ratio and catenary resistance. Results indicate that the greater the catenary resistance, the more advantageous eco-driving is. Similarly, the lower the motor efficiency, the greater the energy savings provided by efficient driving. Despite the differences observed in energy savings, the main conclusion is that eco-driving always provides significant energy savings, even in the case of the most receptive power supply network. Therefore, this paper has demonstrated that efforts in improving regenerated energy usage must not neglect the role of eco-driving in railway efficiency

GENETIC ALGORITHM-PID CONTROLLER FOR MODEL ORDER REDUCTION PANTOGRAPHCATENARY SYSTEM

Controlling the contact force between the pantograph and the catenary has come to be a requirement for improving the performances and affectivity of high-speed train systems Indeed, these performances can also significantly be decreased due to the fact of the catenary equal stiffness variation. In addition, the contact force can also additionally differ and ought to end up null, which may additionally purpose the loss of contact. Then, in this paper, we current an active manipulate of the minimize order model of pantograph-catenary system .The proposed manipulate approach implements an optimization technique, like particle swarm (PSO), the usage of a frequent approximation of the catenary equal stiffness. All the synthesis steps of the manipulate law are given and a formal evaluation of the closed loop stability indicates an asymptotic monitoring of a nominal steady contact force. Then, the usage of Genetic Algorithm with Proportional-Integral-derivative (G.A-PID) as proposed controller appeared optimum response where, the contacts force consequences to be virtually equal to its steady reference. Finally it seems the advantageous of suggestion approach in contrast with classical manipulate strategies like, Internal mode control(IMC) method, linear quadratic regulator (LQR).The outcomes via the use of MATLAB simulation, suggests (G.A-PID) offers better transient specifications in contrast with classical manipulate

Advances in fault diagnosis for high-speed railway: A review

The high speed railway (HSR) is a complex system with many subsystems and components. The reliability of its core subsystems is a key consideration in ensuring the safety and operation efficiency of the whole system. As the service time increases, the degradation of these subsystems and components may lead to a range of faults and deteriorate the whole system performance. To ensure the operation safety and to develop reasonable maintenance strategies, fault detection and isolation is an indispensable functionality in high speed railway systems. In this paper, the traction power supply system, bogie system, civil infrastructure system, and control and signaling system of HSR are briefly summarized, and then different fault diagnosis methods for these subsystems are comprehensively reviewed. Finally, some future research topics are discussed

Design and Testing of an Innovative Pressure-Controlled Active Pantograph through Hardware-in-the-Loop Experiments

On railways with overhead lines, pantographs play a crucial role in electric trains. Maintaining the contact force between the pantograph and the overhead line is essential to ensure the robustness of the power supply and to minimise mechanical wear. This paper proposes an innovative pneumatic pressure-controlled active pantograph, tested through Hardware-in-the-Loop (HIL) experiments. The proposed easy-to-implement active pantograph is achieved by controlling the air pressure entering the pantograph. The controller design is based on an identified linear model, considering disturbance rejection performance and control input limitations. Experimental results show that the closed-loop active pantograph can robustly and effectively reduce the contact force deviation. This highlights the capability of designing active pantographs through pressure control and model-based design philosophy to achieve improved pantograph–catenary contact performance

A novel Active Control of Trolleybus Current Collection System (ACTCCS)

The trolleybus has been a popular public transport vehicle for more than a hundred years across the world. However, the typical features of double passive pantograph-booms with two-wire overhead line often creates complicated catenary webs (particularly at crossroads) and can result in easily de-wiring and arcing issues. In this thesis, a novel concept of Active Control of Trolleybus Current Collection System (ACTCCS) is introduced with actuator-controlled solo-pantograph and single overhead line (catenary formed by two wires fitted on a frame with enough electric clearance and creep) as well as electric (traction)-electric (battery or supercapacitor backup) hybrid (E-E hybrid) propulsion. [Continues.

Efficient simulation of the pantograph-catenary dynamic interaction. Catenary optimisation and installation error analysis

Tesis por compendioEl modelado y la simulación de la interacción dinámica entre el pantógrafo y la catenaria se ha convertido en una herramienta imprescindible para agilizar el proceso de diseño de catenarias ferroviarias ya que, entre otras ventajas, es posible reducir el número necesario de los tan costosos ensayos experimentales en vía. Para la realización de dichas simulaciones numéricas, la catenaria se modela mediante el método de los Elementos Finitos, mientras que el modelo del pantógrafo es de parámetros concentrados. La interacción entre ambos sistemas se trata con un método de penalti. Tras resolver el problema no lineal de configuración inicial, la ecuación del movimiento se linealiza, y se resuelve con la técnica HHT. Sin embargo, el aflojamiento de las péndolas y los despegues del pantógrafo son dos fuertes no linealidades que deben ser consideradas en la resolución del problema dinámico, aunque aumenten notablemente el coste computacional de cada simulación. Los objetivos principales de esta Tesis son encontrar catenarias óptimas en términos de calidad de captación de corriente y analizar los efectos de los errores de montaje de la catenaria. Para alcanzarlos, es necesario realizar un número elevado de simulaciones de la interacción dinámica entre pantógrafo y catenaria, cuyo coste computacional puede llegar a ser prohibitivo. Para reducir el coste computacional, la primera propuesta se basa en el cálculo de una solución paramétrica de la interacción dinámica entre pantógrafo y catenaria, para cualquier valor de las variables de diseño, por medio de la técnica Proper Generalised Decomposition (PGD). Si las longitudes de las péndolas son consideradas como variables de diseño, la aplicación de este método resulta exitosa en el caso del problema de equilibrio estático, pero no en el caso del dinámico, donde se considera que las péndolas no transmiten fuerzas a compresión. La solución del problema resulta muy sensible ante pequeños cambios de las variables y por tanto, se requiere de un elevado número de modos PGD para tener una solución paramétrica de suficiente precisión. La segunda propuesta consiste en el desarrollo de una estrategia para resolver el problema de interacción dinámica con la que se reduzca considerablemente el tiempo de cálculo. El algoritmo propuesto se divide en dos fases y se basa en pasar los términos no lineales a la parte derecha de la ecuación de la dinámica del sistema. Tras el cálculo y almacenamiento de la respuesta ante fuerzas unitarias, en la segunda etapa del método, el tratamiento de las no linealidades se condensa en un sistema de ecuaciones pequeño cuyas incógnitas son las fuerzas relacionadas con dichas no linealidades, en vez de los desplazamientos nodales globales. Con este algoritmo eficiente, es posible llevar a cabo la optimización de la geometría de catenarias ferroviarias. En concreto, la altura del cable de contacto y la separación entre péndolas son los parámetros de diseño a optimizar para obtener así una captación de corriente óptima. El problema de optimización se resuelve mediante un Algoritmo Genético clásico, y se aplica a diferentes tipos de catenarias. Los resultados obtenidos indican que un diseño óptimo de la geometría puede mejorar notablemente la captación de corriente de las catenarias actuales. Finalmente, se estudia la influencia que tienen los errores de montaje de la catenaria en el comportamiento dinámico del sistema. Con un planteamiento estocástico, se considera variabilidad en la longitud de las péndolas, en la separación entre ellas y en la altura de los soportes. Mediante la aplicación un método clásico de Montecarlo, se propaga la incertidumbre a las magnitudes de interés y se obtiene su función de densidad de probabilidad. Los resultados muestran que los errores cometidos en la colocación de las péndolas apenas influyen en la respuesta del sistema, mientras que errores en lModelling and simulation of the dynamic interaction between pantograph and catenary has become a powerful tool to expedite the catenary design process since, among other advantages, it helps in reducing the number of the costly experimental in-line tests. In order to tackle these numerical simulations, in this Thesis the catenary system is modelled by the Finite Element technique, while a simple lumped-mass model is used for the pantograph. The interaction between the two systems is accomplished with a penalty formulation. After solving the initial nonlinear configuration problem, the equation of motion is linearised with respect to the static equilibrium position and it is then solved by applying the Hilber-Hughes-Taylor (HHT) time integration method. However, dropper slackening and pantograph contact losses are two sources of nonlinearities which must be considered in the solution procedure at the expense of an increase in the computational cost. The main objectives of this Thesis are both to find optimal catenaries in terms of current collection quality and to analyse the effect of installation errors in the dynamic behaviour of the system. To achieve these goals, it is mandatory to perform a large number of pantograph-catenary dynamic simulations for which the computational cost can become prohibitive. In order to reduce this computational effort, the first proposal made in this Thesis is to precompute a parametric solution of the pantograph-catenary dynamic interaction for all values of the design variables, by means of the Proper Generalised Decomposition (PGD) technique. If dropper lengths are considered as design variables, this parametric approach is successful when applied to the static equilibrium problem. Nevertheless, in the dynamic case, when dropper slackening is considered, the solution exhibits a great sensitivity to small changes in the parameters and therefore, a huge number of PGD modes are required to obtain the parametric solution with enough accuracy. The impossibility of having a parametric solution leads the author to propose a fast strategy to simulate the dynamic interaction problem, providing remarkable saves in computational cost. The method is divided into two stages which are based on moving the nonlinear terms to the right hand side of the dynamic equation. In the first stage, the response of the system under unitary forces is precomputed and stored. Then, in the second stage of the method, the treatment of the nonlinearities is condensed into a small system of equations, whose unknowns are now the forces associated with the nonlinearities instead of the nodal displacements of the whole system. With this proposed algorithm, it is possible to carry out efficient optimisations of the catenary geometry. Specifically, contact wire height and dropper spacing are considered as design variables in order to obtain the most uniform interaction force that leads to the optimal current collection. The optimisation problem is solved by means of a classic Genetic Algorithm, applied to both simple and stitched catenaries. The results obtained show that an optimal catenary design can remarkably improve the current collection quality of the actual catenaries. Finally, the influence of the installation errors on the dynamic behaviour of the system is analysed under a stochastic approach in which variability in dropper length, dropper spacing and support height are involved in the simulations. The use of a Monte Carlo method allows the propagation of the uncertainty to the magnitudes of interest of the dynamic solution and therefore, to obtain their probability density function. The results of Monte Carlo simulations demonstrate that dropper spacing errors are slightly influential, whilst dropper length and supsupport height installation errors have a strong influence on the dynamic behaviour of the system.El modelatge i la simulació de la interacció dinàmica entre el pantògraf i la catenària ha esdevingut en una ferramenta imprescindible per a agilitzar el procés de disseny de catenàries ferroviàries degut, entre altres coses, a la possibilitat de reduir el nombre dels tan costosos assajos experimentals en via. Per a la realització d'aquestes simulacions numèriques, la catenària es modela mitjançant el mètode dels Elements Finits, mentre que el model de pantògraf és de paràmetres concentrats. La interacció entre ambdós sistemes es tracta amb un mètode de penalti. Després de resoldre el problema no-lineal de configuració inicial, l'equació del moviment es linealitza i es resol amb la tècnica HHT. Tanmateix, l'afluixament de les pèndoles a compressió i la pèrdua de contacte del pantògraf són dues fortes no-linealitats que han de ser considerades en la resolució del problema dinàmic, malgrat l'augment que produeixen del cost computacional de cada simulació. Els objectius principals d'aquesta Tesi són trobar catenàries òptimes en termes de qualitat de captació de corrent i analitzar els efectes dels errors de muntatge de la catenària. Per a assolir-los és necessari realitzar un nombre elevat de simulacions de la interacció dinàmica entre pantògraf i catenària, el que pot comportar un cost computacional prohibitiu. Per tal de reduir el cost computacional, la primera proposta consisteix a calcular una solució paramètrica del problema d'interacció dinàmica entre pantògraf i catenària, per a qualsevol valor de les variables de disseny, mitjançant la tècnica Proper Generalised Decomposition (PGD). Si les longituds de les pèndoles es consideren com a variables de disseny, l'aplicació d'aquest mètode és exitosa en el cas del problema d'equilibri estàtic, però no en el cas del dinàmic, on es considera que les pèndoles no poden transmetre força a compressió. La solució del problema és molt sensible a xicotets canvis de les variables i per tant, es necessita un elevat nombre de modes PGD per a obtenir una solució paramètrica amb suficient precisió. La segona proposa consisteix en el desenvolupament d'una estratègia per a resoldre el problema d'interacció dinàmica que reduïsca considerablement el temps de simulació. L'algoritme proposat es divideix en dues fases i es basa a moure els termes no lineals a la part dreta de l'equació de la dinàmica del sistema. Després de calcular i s'emmagatzemar la resposta del sistema a forces unitàries, en la segona etapa del mètode, el tractament de les no linealitats es condensa en un xicotet sistema d'equacions les incògnites del qual passen a ser forces en compte de desplaçaments. Amb aquest algoritme eficient, s'ha pogut realitzar l'optimització de la geometria de catenàries ferroviàries. En concret, l'altura del cable de contacte i la separació entre pèndoles es consideren com a paràmetres a optimitzar per a obtenir una òptima captació de corrent. L'optimització es porta a terme mitjançant un Algoritme Genètic clàssic, i s'aplica a diferents tipus de catenàries. Els resultats obtinguts indiquen que un disseny òptim de la geometria pot millorar notablement la captació de corrent de les actuals catenàries. Finalment s'estudia la influència que tenen les errades de muntatge de la catenària en el comportament dinàmic del sistema. Aquest plantejament estocàstic considera variabilitat en la longitud de les pèndoles, la separació entre aquestes i l'altura dels suports. Per mitjà d'un mètode clàssic de Montecarlo, es propaga la incertesa a les magnituds d'interés i s'obté la seua funció de densitat de probabilitat. Els resultats mostren que hi ha molt poca influència per part de les errades comeses en la col·locació de les pèndoles, mentre que errades en la longitud de les pèndoles i en l'altura dels suports sí que influeixen considerablement en el comportament dinàmic del sistema.Gregori Verdú, S. (2018). Efficient simulation of the pantograph-catenary dynamic interaction. Catenary optimisation and installation error analysis [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/104507TESISCompendi

A simplify fuzzy logic controller design based safe experimentation dynamics for pantograph-catenary system

Contact force between catenary and pantograph of high speed train is a crucial system to deliver power to the train. The inconsistence force between them can cause the contact wire oscillate a lot and it can damage the mechanical structure of system and produce electric arc that can reduce the performance of system. This project proposes a single-input fuzzy logic controller (SIFLC) to control the contact force between the pantograph-catenary by implement Safe Experimentation Dynamics (SED) method to tune the SIFLC parameters. The essential feature of SIFLC is that it is model-free type controller design with less pre-defined variables as compared to other existing model-based controllers. The performance of the SIFLC is analyzed in terms of input tracking of contact force of pantograph-catenary and time response specifications. A simplified model of three degree of freedom (3-DOF) pantograph-catenary system is considered. In this study, the simulation result shows that the SIFLC successfully track the given contact force with less overshoot with percentage different of peak to peak response from actual force 2% and fast response within 5.27s