Investigation of a tubular linear transverse flux machine for use with a free-piston engine

PhD ThesisThis thesis explores different topologies of permanent magnet linear electric machines for use with a renewable engine – Free-Piston Engine. By comparing their performances, it aims to prove that a new linear modulate pole (transverse flux) machine can be the best overall topology. Five candidate topologies including longitudinal flux and transverse flux types are presented and simulated by finite element analysis method in MagNet software. The designer optimises each topology with the same effort and strategy by using an advanced algorithm in OptiNet software. The transverse flux and flux switching topology are detailed compared with different optimisation strategies to investigate machine performances. The designer performs an advanced design study on the modulated pole machine to simplify the manufacturing process, reduce building cost and improve output performance. The process includes the tooth combination design, the single tooth winding design and the lamination design. The designer expands the insight of the final designed modulated pole machine. The force production and power factor derivation are performed theoretically and numerically. The numerical solution is compared to the simulation result for validation. Detailed mechanical design for the final designed modulate pole machine is performed consisting of: the shaft strength investigation, the stator assembly strategy, the winding assembly and drive linear actuator selection. The designer tests the final build modulate pole machine in both static and dynamic conditions. Static tests include cogging force test and DC test. Dynamic tests include EMF test and short circuit current test. All results are compared with simulations for machine quality check. The thesis demonstrates that the tubular transverse flux machine is manufacturable and fulfil the requirements of a Free-Piston Engine

Advances in Theoretical and Computational Energy Optimization Processes

The paradigm in the design of all human activity that requires energy for its development must change from the past. We must change the processes of product manufacturing and functional services. This is necessary in order to mitigate the ecological footprint of man on the Earth, which cannot be considered as a resource with infinite capacities. To do this, every single process must be analyzed and modified, with the aim of decarbonising each production sector. This collection of articles has been assembled to provide ideas and new broad-spectrum contributions for these purposes

Magnetic Guidance for Linear Drives

Linear drives provide many new attractive solutions for the material transportation and processing in the manufacturing industry. With no mechanical transmission elements, they enable high dynamics and rigidity as well as low installation- and low maintenance-costs. That performance can give the linear motor system a better precision, a higher acceleration and a higher speed of the moving part. Therefore, the material transportation and processing using linear motors is studied and applied increasingly in manufacturing industry. For these applications, the linear motor is typically with stationary long primary and a short moving secondary. As the secondary part is passive, no energy transmission is required between the moving and stationary part, avoiding the use of brushes or inductive transmission. The motor type best suited for the mentioned applications is the synchronous one with permanent magnets, because of its higher efficiency, compactness, but most important because it allows a higher air-gap. In the usual approach, the linear motor is only used for thrust force production. The guidance is usually implemented by a mechanical assembly. The guidance constrains the movement to the longitudinal displacement, fixing the lateral and vertical displacement: yaw, roll and pitch. To achieve the necessary precision of the movement, accurate mechanical guidance is required. Such the mechanical assembly can be complex and source of high friction. In this dissertation, a research of an active guiding system is presented. The purpose of this research is finding out a solution for the material transportation and processing applications. The target is a linear drive system, which can reduce the complicated mechanical structure. In additions, the passive vehicle is also necessary. The result of the research is PM-synchronous linear motors with long and double-sided primaries. In the system, the lateral displacement and the yaw angle are controlled while a simple wheel-rail system fixes the vertical displacement. This combination of the magnetic and mechanical guidance offers a good trade-off among the complexity of the control, actuators and mechanics, when considering industrial applications. To allow multiple vehicles traveling simultaneously and independently on the guide-way (each vehicle is controlled by an individual part of the guide-way), the double side primary is separated into segments. With that structure, flexible-operating methods can be implemented. That is very useful in process-integrated material handling where different speeds of material carriers in each processing station are necessary. Another advantage of segmented structure is the energy saving. The power is supplied only to the segment or the two consecutive segments in which the vehicle runs over. In one segment, each side of the primary is supplied by its own inverter, allowing the necessary degree of freedom to control the lateral position and the yaw angle in addition to the thrust control. In order to make the vehicle completely passive, a capacitive sensor is proposed and implemented to measure the lateral position and the yaw angle. The sensor has active parts installed on the guide-way and passive parts on the vehicle. The mathematical analysis and the finite element method (FEM) are used to analysis the proposed system. With the analysed results, the control for the system is investigated in detail. Hardware and software for the experimental system is developed and implemented. The analysed results and the experimental results validate the proposed system. That gives a new solution for the material transportation and processing application using linear synchronous motors

Magnetic Material Modelling of Electrical Machines

The need for electromechanical energy conversion that takes place in electric motors, generators, and actuators is an important aspect associated with current development. The efficiency and effectiveness of the conversion process depends on both the design of the devices and the materials used in those devices. In this context, this book addresses important aspects of electrical machines, namely their materials, design, and optimization. It is essential for the design process of electrical machines to be carried out through extensive numerical field computations. Thus, the reprint also focuses on the accuracy of these computations, as well as the quality of the material models that are adopted. Another aspect of interest is the modeling of properties such as hysteresis, alternating and rotating losses and demagnetization. In addition, the characterization of materials and their dependence on mechanical quantities such as stresses and temperature are also considered. The reprint also addresses another aspect that needs to be considered for the development of the optimal global system in some applications, which is the case of drives that are associated with electrical machines

A Novel Design Optimization of a Fault-Tolerant AC Permanent Magnet Machine-Drive System

In this dissertation, fault-tolerant capabilities of permanent magnet (PM) machines were investigated. The 12-slot 10-pole PM machines with V-type and spoke-type PM layouts were selected as candidate topologies for fault-tolerant PM machine design optimization problems. The combination of 12-slot and 10-pole configuration for PM machines requires a fractional-slot concentrated winding (FSCW) layout, which can lead to especially significant PM losses in such machines. Thus, a hybrid method to compute the PM losses was investigated, which combines computationally efficient finite-element analysis (CE-FEA) with a new analytical formulation for PM eddy-current loss computation in sine-wave current regulated synchronous PM machines. These algorithms were applied to two FSCW PM machines with different circumferential and axial PM block segmentation arrangements. The accuracy of this method was validated by results from 2D and 3D time-stepping FEA. The CE-FEA approach has the capabilities of calculating torque profiles, induced voltage waveforms, d and q-axes inductances, torque angle for maximum torque per ampere load condition, and stator core losses. The implementation techniques for such a method are presented. A combined design optimization method employing design of experiments (DOE) and differential evolution (DE) algorithms was developed. The DOE approaches were used to perform a sensitivity study from which significant independent design variables were selected for the DE design optimization procedure. Two optimization objectives are concurrently considered for minimizing material cost and power losses. The optimization results enabled the systematic comparison of four PM motor topologies: two different V-shape, flat bar-type and spoke-type, respectively. A study of the relative merits of each topology was determined. An automated design optimization method using the CE-FEA and DE algorithms was utilized in the case study of a 12-slot 10-pole PM machine with V-type PM layout. An engineering decision process based on the Pareto-optimal front for two objectives, material cost and losses, is presented together with discussions on the tradeoffs between cost and performance. One optimal design was finally selected and prototyped. A set of experimental tests, including open circuit tests at various speeds and on-load tests under various load and speed conditions, were performed successfully, which validated the findings of this work

Numerical analysis of a brushless permanent magnet DC motor using coupled systems

Ph.DDOCTOR OF PHILOSOPH

Real-time FPGA-based co-simulation of large scale power systems

With the rapid increase of size and complexity of modem electrical power systems, 1) the simulation accuracy and 2) the capability of simulating large power systems have become two conflicting objectives. This thesis proposes a novel FPGA-RTDS co-simulator to meet these two objectives. As the basis of the co-simulator, a library of power system components is developed in FPGA, including the most commonly used power system elements and control systems. The proposed cosimulator combines the advantages of 1) the paralleled architecture, high logic density and high clock speed from FPGA and 2) better modelling flexibility and user-friendly GUI from RTDS together. Multi-FPGA structure is introduced to further improve the simulation capability for large power systems. The use of detailed EMT models in the whole system guarantees the accuracy of simulation and eliminates the potential interface error. Deeply pipelined and massively paralleled algorithms have been designed to maximize time and hardware efficiency. The modular design significantly improves the system expandability. Case studies including large scale power system with more than 4000 nodes are presented to demonstrate the simulation capability. Comparisons are made with SIMULINK and RTDS to verify the accuracy of the proposed co-simulator

Sliding mode control of the stand alone wound rotor synchronous generator

En esta Tesis ha sido analizado el control de la màquina sincrónica de rotor bobinado actuando en isla. Para esta configuración, la velocidad mecànica determina la frecuencia, y la tensión de rotor se utiliza para fijar la amplitud de la tensión de estator. Debido a que la constante de tiempo eléctrica es mucho más ràpida comparada con la constante de tiempo mecánica, la velocidad mecánica fue considerada constante y externamente regulada y la investigación se enfocó en la regulación de la amplitud de la tensión de estator.Cuatro diferentes controladores basados en técnicas de modos deslizantes fueron diseñados en el marco de referencia dq. Las leyes de control obtenidas regulan la amplitud de la tensión de estator independientemte del valor de la carga. Adicionalmente, sólo las medidas de tensión y posición del rotor (para calcular la transformada dq) son necesarias. La estabilidad de los puntos de equilibrio obtenidos fueron probados al menos utilizando anàlisis de pequeña señal.Se realizó la validación por simulación y experimental de cada controlador en diferentes escenarios. Los resultados obtenidos validan los diseños y muestran las principales ventajas y desventajas de el sistema en lazo cerrado.El capítulo 2 cubre los problemas de modelado de la màquina sincrónica de rotor bobinado. Partiendo de las ecuaciones trifásicas generales, y utilizando la transformada de Park, se encontraron el modelo en dq del generador sincrónico de rotor bobinado (WRSG) en isla, alimentando tanto carga resistiva como inductiva. Los puntos de equilibrio del sistema obtenido fueron analizados y calculados, luego se definió el objetivo de control. Finalmente, se obtuvieron modelos lineales aproximados y sus respectivas funciones de transferencia.Los controladores PI son los más usados en la industria porque ofrecen buen desempeño y son sencillos de implementar. En el capítulo 3, se obtuvieron las reglas de sintonización para el controlador PI, y se analizaron estos resultados con el objetivo de proponer nuevos controladores que mejoraran el desempeño de la clásica aproximación PI.El esquema de control en modos deslizantes para la WRSG conectada a una carga resistiva fue diseñado en el capítulo 4. Éste, también incluye un completo análisis de estabilidad del sistema en lazo cerrado. El capítulo 5 presenta dos diseños basados en modos deslizantes para regular la amplitud de la tensión de estator para el WRSG actuando en isla. Ambos diseños usan la componente d de la tensión de estator en la función de conmutación. El primer caso es un control anidado, donde un lazo externo PI es añadido para proveer la referencia de la componente d de la tensión. En la segunda aproximación un término integral es añadido a la superficie de conmutación.El caso de alimentar una carga inductiva es estudiado en el capítulo 6. El controlador requiere una extensión dinámica debido a que la amplitud de la tensión de estator es una salida de grado relativo cero. Como resultado, un controlador robusto, que no depende de los parámetros de la máquina ni de los valores de carga es obtenido. En el capítulo 7 los resultados de simulación y experimentales para los controladores diseñados para el WRSG actuando en isla son presentados. En primer lugar, una descripción completa del banco es presentada. Esta incluye detalles de la etapa de adquisición de datos y de la DSP utilizada. En segundo lugar, se hace la descripción del procedimiento de simulación. Luego, las simulaciones y experimentos, que contienen diferentes escenarios, con cambios de referencia y variaciones de carga para cada controlador son presentados.The control of the stand-alone the wound rotor synchronous generator has been analyzed in this dissertation. For this islanded configuration, the mechanical speed determines the frequency, and the rotor voltage is used to set the stator voltage amplitude. Due to the electrical time constant is so fast compared with the mechanical time constants, the mechanical speed was considered constant and externally regulated and the research was focused on the stator voltage amplitude regulation.Four different controllers based on sliding mode control techniques were designed in the dq reference frame. The obtained control laws regulate the stator voltage amplitude irrespectively of the load value. Furthermore, only voltage and rotor position measures (to compute the dq transformation), are required. The stability of the obtained equilibrium points was proved at least using small-signal analysis. Simulation and experimental validation of each controller containing several scenarios were carried out. The obtained results validate the designs and show the main advantages and disadvantages of each closed loop system. Chapter 2 covers the modeling issues of the wound rotor synchronous machine. From the general three-phase dynamical equations, and using the Park transformation, the dq-model of the stand-alone wound rotor synchronous generator feeding both a resistive and an inductive load are obtained. Equilibrium points of the obtained systems are analyzed and, after defining the control objective, the desired equilibrium points are computed.Finally, linear approximated models are obtained and their transfer functions are also presented.PI controllers are the most used in the industry because they offers good performance and are easily implementables. In Chapter 3 we obtain the tuning rule for the PI controller, and we analyze these results in order to propose new controllers which improve the classic PI approach.The sliding mode control scheme for the WRSG connected to a resistive load is designed in Chapter 4. It also includes a complete stability analysis of the closed loop system. Chapter 5 presents two sliding mode designs to regulate the stator voltage amplitude for a stand-alone wound rotor synchronous generator. Both use the stator voltage d-component error in the switching function. The first case is a nested controller, where an outer PI loop is added to provide the proper d-voltage component reference. In the second approach an integral term is added to the switching function. The case of feeding an inductive load is studied in Chapter 6. The controller introduces a dynamic extension because the stator voltage amplitude is a zero relative degree output. As result, a robust controller, which neither depends on the machine parameters nor on the load values, is obtained. In Chapter 7 the simulation and the experimental results of the designed controllers for the stand-alone wound rotor synchronous generator are presented. Firstly, a complete description of the bench is provided. It also includes details of the data acquisition stage and the used DSP card. Secondly, the description of the simulation procedure is commented. Then, the simulation and experiments which contains several scenarios, with reference change and load variations evaluated for each controller are presented

Proceedings of the 8th International Conference EEMODS'2013 Energy Efficiency in Motor Driven Systems

This book contains the papers presented at the eighth international conference on Energy Efficiency in Motor Driven Systems EEMODS 2013 EEMODS 2013 was organised in Rio de Janeiro, Brasil from 28 to 30 October 2013. This major international conference, which was previously been staged in Lisbon (1996), London (1999), Treviso (2002), Heidelberg (2005), Beijing (2007), Nantes (2009) and Washington DC (2011) has been very successful in attracting an international and distinguished audience, representing a wide variety of stakeholders in policy implementation and development, manufacturing and promotion of energy-efficient motor systems, including key policy makers, equipment manufacturers, academia and end-users. Potential readers who may benefit from this book include researchers, engineers, policymakers, energy agencies, electric utilities, and all those who can influence the design, selection, application, and operation of electrical motor driven systems.JRC.F.7-Renewables and Energy Efficienc

6th European Conference on Energy Efficiency and Sustainability in Architecture and Planning

[ES]Esta obra recoge las comunicaciones seleccionadas para el 6º Congreso Europeo sobre Eficiencia Energética y Sostenibilidad en Arquitectura, organizado por el grupo de investigación Calidad de Vida en Arquitectura de la Universidad del País Vasco/Euskal Herriko Unibertsitatea. El congreso, que se celebra en el marco de los XXXIV Cursos de Verano de la UPV/EHU, aborda en esta cuarta edición el tema “Ciudades en riesgo: resiliencia y redundancia”. Alrededor de este tema general se desarrollan cinco ponencias magistrales, a cargo de Margaretha Breil (Centro Euro-Mediterráneo para el Cambio Climático), Cristina Garzillo Leemhuis (ICLEI), Ignasi Fontanals (OptiCits), Juan Carlos Barrios Montenegro (Global Action Plan) y Manuel Valdés López (Ajuntament de Barcelona). Además, 24 comunicaciones seleccionadas por el comité científico presentarán trabajos de investigaciones actuales en las sesiones orales y póster. Es objetivo paralelo del congreso es fortalecer las líneas de investigación en eficiencia energética y sostenibilidad de los grupos de investigación y formación de la UPV/ EHU comprometidos con esta propuesta, con objeto de colaborar en el reforzamiento de la I D i en su ámbito de conocimiento y apoyar la apuesta específica de los Gobiernos Central y Vasco, así como de otras instituciones nacionales e internacionales respecto a las actividades de I D i en las materias relacionadas con el cambio climático, la eficiencia energética y la sostenibilidad ambiental [ENG] This work contains the selected abstracts of the 6th European Conference on Energy Efficiency and Sustainability in Architecture and Planning, organized by the research group Quality of life in Architecture of the University of the Basque Country. The conference is part of the XXXIV Summer Courses of the UPV/EHU and deals, in its fourth edition, with the topic “Cities at risk: resilience and redundancy”. Around this general theme there are five invited speakers: Margaretha Breil (Euro-Mediterranean Centre for Climate Change), Cristina Garzillo Leemhuis (ICLEI), Ignasi Fontanals (OptiCits), Juan Carlos Barrios Montenegro (Global Action Plan) y Manuel Valdés López (Barcelona City Council). 24 abstracts additional have been selected by the scientific committee that offer actual research works in presentations and posters. The purpose of the conferences is to strengthen the investigation lines in energy efficiency and sustainability of the research and education groups of the University of the Basque Country (UPV/EHU) involved, with the purpose of collaborating in the reinforcement of the I D i in its field of knowledge, and support the specific projects of the Central and Basque Governments, as well as other national and international institutions related to the I Di activities in similar fields of climate change, energy efficiency and environmental sustainability