Traction axial flux motor-generator for hybrid electric bus application

Tato dizertační práce se zabývá návrhem původního motor-generátoru s axiálním tokem a buzením permanetními magnety, zkonstruovaným specificky pro hybridní elektrický autobus. Návrhové zadání pro tento stroj přineslo požadavky, které vedly k této unikátní topologii tak, aby byl dosažen výkon, účinnost a rozměry stroje. Tato partikulární topologie motor-generátoru s axiálním tokem je výsledkem literární rešerše, kterou následoval výběr koncepce stroje s představeným návrhem jako výsledkem těchto procesů. Přístup k návrhu stroje s axiálním tokem sledoval „multi-fyzikální“ koncepci, která pracuje s návrhem elektromagnetickým, tepelným, mechanickým, včetně návrhu řízení, v jedné iteraci. Tím je v konečném návrhu zajištěna rovnováha mezi těmito inženýrskými disciplínami. Pro samotný návrh stroje byla vyvinuta sada výpočtových a analytických nástrojů, které byly podloženy metodou konečných prvků tak, aby samotný návrh stroje byl přesnější a spolehlivější. Modelování somtného elektrického stroje a celého pohonu poskytlo představu o výkonnosti a účinnosti celého subsytému v rozmanitých operačních podmínkách. Rovněž poukázal na optimizační potenciál pro návrh řízení subsystému ve smyslu maximalizace účinnosti celého pohonu. Bylo postaveno několik prototypů tohoto stroje, které prošly intensivním testováním jak na úrovni sybsytému, tak systému. Samotné výsledky testů jsou diskutovány a porovnány s analytickými výpočty parametrů stroje. Poznatky získané z prvního prototypu stroje pak sloužily k představení možností, jak zjednodušit výrobu a montáž stroje v příští generaci. Tato práce zaznamenává jednotlivé kroky během všech fází vývoje elektrického stroje s axiálním tokem, počínaje výběrem konceptu stroje, konče sumarizací zkušeností získaných z první generace prototypu tohoto stroje.This thesis deals with a design of a novel Axial-Flux Permanent Magnet Motor-Generator for a hybrid electric bus application. Thus, the design specification represents a set of requirements, which leads toward a concept of a unique topology meeting performance, efficiency and dimensional targets. The particular topology of the Axial-Flux Permanent Magnet Motor-Generator discussed in this work is an outcome of deep literature survey, followed by the concept selection stage with the layout of the machine as an outcome of this processes. The design approach behind this so-called Spoke Axial-Flux Machine follows an idea of multiphysics iterations, including electromagnetic, thermal, mechanical and controls design. Such a process behind the eventually proposed design ensured a right balance in between all of these engineering disciplines. A set of bespoke design and analysis tools was developed for that reason, and was backed up by extensive use of Finite-Element Analysis and Computational Fluid Dynamics. Therefore, the actual machine design gained higher level of confidence and fidelity. Modelling of the machine and its drive provided understanding of performance and efficiency of the whole subsystem at various operational conditions. Moreover, it has illustrated an optimization potential for the controls design, so that efficiency of the machine and power electronics might be maximized. Several prototypes of this machine have been built and passed through extensive testing both on the subsystem and system level. Actual test results are discussed, and compared to analytical predictions in terms of the machine's parameters. As a lesson learned from the first prototype of this machine, a set of redesign proposals aiming for simplification of manufacturing and assembly processes, are introduced. This work records steps behind all phases of development of the Axial Flux Machine from a basic idea as an outcome of concept selection stage, up to testing and wrap-up of experience gained from the first generation of the machine.

Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

A scalable life cycle inventory of an electrical automotive traction machine—part I: design and composition

Purpose: A scalable life cycle inventory (LCI) model of a permanent magnet electrical machine, containing both design and production data, has been established. The purpose is to contribute with new and easy-to-use data for LCA of electric vehicles by providing a scalable mass estimation and manufacturing inventory for a typical electrical automotive traction machine. The aim of this article (part I of two publications) is to present the machine design, the model structure, and an evaluation of the models’ mass estimations. Methods: Data for design and production of electrical machines has been compiled from books, scientific papers, benchmarking literature, expert interviews, various specifications, factory records, and a factory site visit. For the design part, one small and one large reference machine were constructed in a software tool, which linked the machines’ maximum ability to deliver torque to the mass of its electromagnetically active parts. Additional data for remaining parts was then gathered separately to make the design complete. The two datasets were combined into one model, which calculates the mass of all motor subparts from an input of maximum power and torque. The range of the model is 20–200 kW and 48–477 Nm. The validity of the model was evaluated through comparison with seven permanent magnet electrical traction machines from established brands. Results and discussion: The LCI model was successfully implemented to calculate the mass content of 20 different materials in the motor. The models’ mass estimations deviate up to 21% from the examples of real motors, which still falls within expectations for a good result, considering a noticeable variability in design, even for the same machine type and similar requirements. The model results form a rough and reasonable median in comparison to the pattern created by all data points. Also, the reference motors were assessed for performance, showing that the electromagnetic efficiency reaches 96–97%. Conclusions: The LCI model relies on thorough design data collection and fundamental electromagnetic theory. The selected design has a high efficiency, and the motor is suitable for electric propulsion of vehicles. Furthermore, the LCI model generates representative mass estimations when compared with recently published data for electrical traction machines. Hence, for permanent magnet-type machines, the LCI model may be used as a generic component estimation for LCA of electric vehicles, when specific data is lacking

A scalable life cycle inventory of an electrical automotive traction machine—part I: design and composition

Purpose: A scalable life cycle inventory (LCI) model of a permanent magnet electrical machine, containing both design and production data, has been established. The purpose is to contribute with new and easy-to-use data for LCA of electric vehicles by providing a scalable mass estimation and manufacturing inventory for a typical electrical automotive traction machine. The aim of this article (part I of two publications) is to present the machine design, the model structure, and an evaluation of the models’ mass estimations. Methods: Data for design and production of electrical machines has been compiled from books, scientific papers, benchmarking literature, expert interviews, various specifications, factory records, and a factory site visit. For the design part, one small and one large reference machine were constructed in a software tool, which linked the machines’ maximum ability to deliver torque to the mass of its electromagnetically active parts. Additional data for remaining parts was then gathered separately to make the design complete. The two datasets were combined into one model, which calculates the mass of all motor subparts from an input of maximum power and torque. The range of the model is 20–200 kW and 48–477 Nm. The validity of the model was evaluated through comparison with seven permanent magnet electrical traction machines from established brands. Results and discussion: The LCI model was successfully implemented to calculate the mass content of 20 different materials in the motor. The models’ mass estimations deviate up to 21% from the examples of real motors, which still falls within expectations for a good result, considering a noticeable variability in design, even for the same machine type and similar requirements. The model results form a rough and reasonable median in comparison to the pattern created by all data points. Also, the reference motors were assessed for performance, showing that the electromagnetic efficiency reaches 96–97%. Conclusions: The LCI model relies on thorough design data collection and fundamental electromagnetic theory. The selected design has a high efficiency, and the motor is suitable for electric propulsion of vehicles. Furthermore, the LCI model generates representative mass estimations when compared with recently published data for electrical traction machines. Hence, for permanent magnet-type machines, the LCI model may be used as a generic component estimation for LCA of electric vehicles, when specific data is lacking

Development of Aluminim/Steel hybrid structures by semisolid forming

Weight reduction is the most cost-effective mean to improve fuel economy and greenhouse gas emissions from the transportation sector. Combining steel and aluminum in a hybrid structure will implement the integrated load-supporting of steel with the advantages of aluminum in weight reduction. However, due to the highly differing physical and mechanical properties, metallurgical bonds between these materials are difficult to achieve with traditional welding methods. These differences in properties lead to the formation of hard and brittle intermetallic compounds along the transition line which will significantly decrease the mechanical properties of the joining area. Production of hybrid components by thixoformig of aluminum on steel is a promising method to manufacture near net shape components with good mechanical properties in a single process step. This process allows joining dissimilar materials in semisolid state at lower temperatures than traditional welding methods, causing a decrease in thickness of the intermetallic layer. In this work, the mount of the front cradle of the car was manufactured in different aluminum alloys and joined to a S355JH2 quality steel tube by thixo transverse forging method. The first part of the dissertation focuses on design and simulation of an automotive hybrid structure and the development of a semi-industrial thixoforming cell. Influence of the main processing parameters such as, solid fraction, mold temperature, compaction time and punch speed are studied. In order to determine the optimum process parameters a thorough mechanical and metallographic analysis of the manufactured components is carried out. The second part of the dissertation deals with fundamental research on the formation and evolution of intermetallic phases when joining of AlSiMg alloys to raw and coated steel, at different joining temperatures in the semisolid range. The results reveal that quality hybrid components can be achieved with this forming method.La reducción de peso es lo más rentable para mejorar la economía de combustible y reducir las emisiones de gases de efecto invernadero procedentes del sector transporte. La unión de ambos materiales permite la creación de nuevas estructuras híbridas que combinan la dureza y resistencia al desgaste de los aceros con la baja densidad de las aleaciones de aluminio. Sin embargo, debido a las propiedades físicas y mecánicas dispares de estos metales, es difícil obtener uniones metalúrgicas con métodos de soldadura tradicionales. Estas diferencias en las propiedades conducen a la formación de compuestos intermetálicos en la intercara que por su naturaleza dura y frágil resultan perjudiciales para su aplicación final. La producción de estructuras híbridas mediante tixoconformado de aluminio sobre acero en un único paso es un proceso prometedor para la fabricación de componentes funcionales con buenas propiedades mecánicas. Este proceso permite unir materiales disimilares en estado semisólido, de forma que la unión de los materiales ocurre a una temperatura inferior que en los métodos tradicionales de soldadura, provocando una disminución del espesor de la capa intermetálica. En el presente trabajo, se ha fabricado un componente real de automoción llamado brazo de la cuna delantera en diferentes aleaciones de aluminio y unido a un tubo de acero de calidad S355JH2. La primera parte de la tesis se centra en el diseño y simulación de una estructura híbrida de automoción y el desarrollo de una célula de tixoconformado semi-industrial. También, se estudia la influencia de los principales parámetros de proceso tales como, fracción sólida, la temperatura del molde, el tiempo de compactación y la velocidad de conformado. Con el fin de determinar los parámetros de proceso óptimos se ha llevado a cabo un exhaustivo análisis mecánico y metalográfico de los componentes fabricados. La segunda parte de la tesis se ocupa de la investigación fundamental de la formación y evolución de las fases intermetálicas que surgen cuando se unen aleaciones AlSiMg con acero en bruto y revestido, a diferentes temperaturas de unión del rango semisólido. Los resultados revelan que es posible obtener componentes híbridos de calidad mediante este proceso de conformado.Ibilgailuen pisua murrizteak eragin nabarmena du erregai-ekonomian eta garraioaren sektoreko berotegi-efektuko emisioak gutxitzean. Bi material horien elkarteak egitura hibrido berriak sortzeko aukera ematen du, zeinak konbinatzen baitituzte altzairuen gogortasuna eta higadurarekiko erresistentzia aluminio-aleazioen dentsitate txikiarekin. Nolanahi ere, konplexua da material desberdinen arteko elkarteak sortzea, ezaugarri desberdinak baitituzte. Ohiko aluminio-altzairu soldaduren kasuan, aluminiotan aberatsak diren metal arteko konposatuak sortzen dira; baina gogorrak eta hauskorrak direnez, kaltegarriak dira azken aplikaziorako. Bestalde, halako elkarte-teknologiek muga handiak dituzte egitura mistoaren geometriari dagokionez. Altzairuaren gaineko aluminiozko egitura hibridoak tixokonformazio bidez urrats bakarrean ekoiztea etorkizun handiko prozesua da propietate mekaniko onak dituzten osagarriak lortzeko. Prozesu honen bidez, material desberdinak elkartu daitezke bestelako soldadura-prozezuetan baino tenperatura baxuagoan eta, horrela, sortutako metalen arteko geruzaren lodiera murrizten da. Lan honetan, aluminiozko aleazio ezberdinen eta 355JH2 kalitatezko altzairuen arteko forja inguruko erdisolidoaren lotura-prozesuaren teknologia garatu da, automobil-industriarako prestazio handiko segurtasun-osagaien ekoizpenean erabili ahal izateko helburuarekin. Tesiaren lehen atalaren ardatza izan da ibilgailuetarako egitura hibrido bat diseinatzea eta simulatzea, eta tixokonformazio erdiindustrialeko zelda bat garatzea. Halaber, prozesuko parametro nagusien eragina aztertu da; besteak beste, hauena: frakzio solidoa, moldearen tenperatura, trinkotze-denbora eta konformazio-abiadura. Prozesuko parametro optimoak zein diren zehazteko, ekoitzitako osagaien analisi mekaniko eta metalografiko sakona egin da. Tesiaren bigarren atalean, bestalde, AlSiMg aleazioak altzairu gordinarekin eta estalduradunarekin elkartzean sortzen diren fase intermetalikoen formazioaren eta eboluzioaren oinarrizko ikerketa egin da. Emaitzek agerian utzi dute posible dela kalitateko osagai hibridoak lortzea konformazio-prozesu honen bitartez

Definition and verification of a set of reusable reference architectures for hybrid vehicle development

Current concerns regarding climate change and energy security have resulted in an increasing demand for low carbon vehicles, including: more efficient internal combustion engine vehicles, alternative fuel vehicles, electric vehicles and hybrid vehicles. Unlike traditional internal combustion engine vehicles and electric vehicles, hybrid vehicles contain a minimum of two energy storage systems. These are required to deliver power through a complex powertrain which must combine these power flows electrically or mechanically (or both), before torque can be delivered to the wheel. Three distinct types of hybrid vehicles exist, series hybrids, parallel hybrids and compound hybrids. Each type of hybrid presents a unique engineering challenge. Also, within each hybrid type there exists a wide range of configurations of components, in size and type. The emergence of this new family of hybrid vehicles has necessitated a new component to vehicle development, the Vehicle Supervisory Controller (VSC). The VSC must determine and deliver driver torque demand, dividing the delivery of that demand from the multiple energy storage systems as a function of efficiencies and capacities. This control component is not commonly a standalone entity in traditional internal combustion vehicles and therefore presents an opportunity to apply a systems engineering approach to hybrid vehicle systems and VSC control system development. A key non-­‐functional requirement in systems engineering is reusability. A common method for maximising system reusability is a Reference Architecture (RA). This is an abstraction of the minimum set of shared system features (structure, functions, interactions and behaviour) that can be applied to a number of similar but distinct system deployments. It is argued that the employment of RAs in hybrid vehicle development would reduce VSC development time and cost. This Thesis expands this research to determine if one RA is extendable to all hybrid vehicle types and combines the scientific method with the scenario testing method to verify the reusability of RAs by demonstration. A set of hypotheses are posed: Can one RA represent all hybrid types? If not, can a minimum number of RAs be defined which represents all hybrid types? These hypotheses are tested by a set of scenarios. The RA is used as a template for a vehicle deployment (a scenario), which is then tested numerically, thereby verifying that the RA is valid for this type of vehicle. This Thesis determines that two RAs are required to represent the three hybrid vehicle types. One RA is needed for series hybrids, and the second RA covers parallel and compound hybrids. This is done at a level of abstraction which is high enough to avoid system specific features but low enough to incorporate detailed control functionality. One series hybrid is deployed using the series RA into simulation, hardware and onto a vehicle for testing. This verifies that the series RA is valid for this type of vehicle. The parallel RA is used to develop two sub-­‐types of parallel hybrids and one compound hybrid. This research has been conducted with industrial partners who value, and are employing, the findings of this research in their hybrid vehicle development programs

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs