Design, Construction and Evaluation of a Modified Tubular Linear Synchronous Motor

Student Number : 9306442N - PhD thesis - School of Electrical and Information Engineering - Faculty of Engineering and the Built EnvironmentThis thesis describes the design, construction and evaluation of a prototype modified tubular linear synchronous motor. The linear motor has a long static primary and a short permanent magnet mobile secondary. The design is unique in that a tubular topology has been modified to allow access to the moving secondary section. This modification means that this design can be used in long distance applications. The application for this research is the use of linear motors in rope-less vertical trans- portation systems in ultra deep level mines. The design of the linear motor has been analysed from an electrical, magnetic, mechanical and thermal perspective. Finite Element Analysis was used to predict the performance of the linear motor. The design of the secondary section has been optimised to produce the greatest possible thrust force while reducing the effects of the cogging forces. The linear motor has been tested extensively and the results correlate with theoretical predictions from the Finite Element Analysis. This project proves that the modified tubular lin- ear synchronous motor is a viable technology that can be used in rope-less vertical transportation systems

Machine generated vertical vibration in elevators

Vertical vibration deteriorates passenger comfort during an elevator travel. The drive system is a source of vertical vibration as well as the source of energy of the system. This report presents the results of a study of car vertical vibrations generated at the drive system in elevator installations. The elevator system can be considered as a translating assembly of inertia elements coupled and constrained by one-dimensional slender continua. The inertia elements are the car assembly, the counterweight, the traction sheave and other rotating components of the system. According to the roping arrangement and to the ratio of the tangential velocity of the traction sheave to the velocity of the car, the traction elevators can be classified as roped 1:1 or multiple reeving systems: the types examined in the present work are 1:1 and 2:1 traction elevators. Distributed- and lumped-parameter models (DPM and LPM respectively) are developed to calculate the natural frequencies and mode shapes of stationary elevator systems and their results compared. A non-stationary model of a 1:1 roping configuration elevator is developed as well to simulate the elevator acceleration response. The model accommodates the drive system dynamics: it includes the electric motor and the torque and velocity controllers, which ensure that the car follows a prescribed kinematic profile, so that good ride quality of the elevator is achieved. The machine parameters are computed by means of the Finite Element Method simulation software FLUX. With respect to the carcounterweight-sheave-ropes assembly, a LPM and a novel DPM are developed. The elevator dynamics represented by the DPM is described by a partial differential equation set that is discretised by expanding the vertical displacements in terms of the linear stationary mode shapes of a system composed of three masses constrained by the suspension rope. The models are implemented in the MATLAB/Simulink computational environment and the system response is determined through numerical simulation. It is shown that the LPM forms a good approximation of the DPM. Experimental tests are carried out on laboratory models. The elasticity modulus of the rope and the friction coefficients at the guide rail contact and at the machine are estimated. The acceleration response at the suspended masses and at the drive machine, the machine shaft velocity and the three phase current intensities supplied to the machine are measured during several travels. The machine torque is estimated from the current intensities. The computed and measured accelerations are compared either in time or frequency domain and it is demonstrated that the elevator car vibrates at frequencies generated at the machine, especially when they are close to the system natural frequencies. The proposed simulation models can be used as design and analysis tools in the development of high-performance elevator systems

Vibration characterisation for fault detection and isolation in linear synchronous motor based conveyor systems

Linear synchronous motor (LSM) based transport systems are increasingly deployed in automated manufacturing environments. The aim of the study is to establish the feasibility of employing low power and low-cost vibration sensing cyber physical systems to perform near real-time fault detection and isolation for passive LSM vehicles. Empirical data capture was conducted on an LSM test-bed where vehicle velocity was varied to determine how changes in velocity would impact the vibration profile of the LSM vehicle. The recorded data was analyzed, and peak accelerations were examined for each of the velocities under study. Frequency domain analysis was conducted on the collated accelerometer data and frequencies of interest were identified. The findings are shown to concur with the manufacturer's operating specifications (0-30 Hz). A relationship between LSM vehicle speed and vibration frequency was established. The results presented provide the basis for the establishment of low-cost condition based preventative maintenance, deployed to a LSM based transport system for high volume manufacturing

On the potential for Electromagnetic Energy Harvesting for a Linear Synchronous Motor based Transport System in Factory Automation

Transport systems incorporating linear synchronous motors (LSMs) enable linear motion at high speed for emerging factory automation applications. The goal of this work is to determine the feasibility of harvesting energy directly from an operational LSM transport system employed in high volume manufacturing. Microelectromechanical (MEMs) based sensor technology, deployed as part of a wireless cyber physical system (CPS), perform near real-time magnetic field measurement for a mobile LSM vehicle. The vehicle under study is purposed for mobile factory automation and is not wired for communications nor does it have an onboard power source. A series of experiments were designed and conducted to establish the magnetic profile of the system. Empirical data capture was conducted on a cycled LSM test-bed comprising of 2 shuttles and 2 x 3 meter lengths of LSM track (MagneMotion QuickStick®100). Varying vehicle speeds were incorporated in the experimental regime to determine how changes in velocity would impact the magnetic profile of the vehicle. The recorded magnetic field data was analysed and a relationship between LSM vehicle speed and magnetic field frequency was established. The study highlights the potential to employ a single receiving coil to enable energy recovery which in turn could power a cyber-physical system (CPS) tasked with performing condition based monitoring of the LSM transport vehicles. This in turn can form the basis for the development of a predictive maintenance system, deployed to an LSM based transport layer in high volume manufacturing environments

Linear Machines for Long Stroke Applications: a review

This document reviews the current state of the art in the linear machine technology. First,the recent advancements in linear induction, switched reluctance and permanent magnet machines arepresented. The ladder slit secondary configuration is identified as an interesting configuration for linearinduction machines. In the case of switched reluctance machines, the mutually-coupled configuration hasbeen found to equate the thrust capability of conventional permanent magnet machines. The capabilities ofthe so called linear primary permanent magnet, viz. switched-flux, flux-reversal, doubly-salient and verniermachines are presented afterwards. A guide of different options to enhance several characteristics of linearmachines is also listed. A qualitative comparison of the capabilities of linear primary permanent magnetmachines is given later, where linear vernier and switched-flux machines are identified as the most interestingconfigurations for long stroke applications. In order to demonstrate the validity of the presented comparison,three machines are selected from the literature, and their capabilities are compared under the same conditionsto a conventional linear permanent magnet machine. It is found that the flux-reversal machines suffer froma very poor power factor, whereas the thrust capability of both vernier and switched-flux machines isconfirmed. However, the overload capability of these machines is found to be substantially lower than theone from the conventional machine. Finally, some different research topics are identified and suggested foreach type of machine

Feasibility and Energy Efficiency of Frequency Converter Driven Synchronous Reluctance Machine in Crane Application

Cranes can use frequency converter driven electrical machines to realize variable speed operations. This thesis discusses if industry favourite induction machine could be replaced by synchronous reluctance machine. Comparative tests have proposed that synchronous reluctance machine is more energy efficient than induction machine. Feasibility of this electrical machine for crane applications needs to be reviewed if this replacement is to be considered. Feasibility and energy efficiency is examined by presenting the operational principles of the compared electrical machines and conducting practical tests with synchronous reluctance machine against a load machine. Presented theory and comparative tests presented no objections against synchronous reluctance machine used for crane application. Practical tests display that synchronous reluctance machine can produce enough torque for crane applications. Tested motor handled zero-speed test cases remarkably well. The motor followed speed commands satisfactorily. Efficiency test results were too low with the tested motor. Efficiency tests faced difficulties, due to which the results are not accurate, but the results can be used to give an indicative view of the efficiency of the tested machine. Synchronous reluctance machine could be used instead of induction machine in cranes, but feasibility requires further research

Implementation of an Automated Vacuum Elevator System

في السنوات الأخيرة أصبح مَصعَد الفراغ الهوائي هو خِياراً شائعاً في بيوتِنا والبنايات المنخفظة. يمثّل مَصعَد الفراغ الهوائي مَفهوم جَديد مُطوّر عن فِكرة استبدال الهواء المضغوط بالهواء المُفرّغ. إنّ مَصعَد الفراغ الهوائي قادر على نقل الأشخاص بين طوابق بناية بدون إستعمال لأيّ أحبال، أو أوزان، أو بكرات. في البحث الحالي تَمّ تركيب وتنفيذ نموذج لمنظومة مَصعَد فراغي كهرو هوائي بسيط ومُنخفض الكُلفة. نموذج نظام المصعَد يتألف من ثلاثة طوابق ويَرفع حُمولة 6 كيلوغرام. تَمّ تَوظيف المُسيطر المنطِقي القابل للبرمجة (PLC)، من سلسلة (LS\GLOFA-G7M-DR30U) ذو (16) مَدخل و(12) مَخرج ومُبرمج ببرامج المُخطط السُلمّي (Ladder)، للسيطرة المُؤتّمَتة الكامِلة على مَنظُومة المَصعَد. مِن المتوقع أن تَنتَشر فِكرة نِظام المَصعَد المُقترح على نحو واسع في البنايات السَكّنية الواطِئة.Pneumatic vacuum elevator (PVE) has become a popular choice for our homes and low-rise buildings in recent years. The Pneumatic vacuum elevator represents a new concept evolved from the idea of pressed air applied in the pneumatic elevator replaced by a vacuum air idea. The pneumatic vacuum elevator is able to transport people between building floors without using any cables, counterweight, or pulleys. A simple and low cost construction and implementation for an Electro-pneumatic vacuum elevator system prototype is presented in this paper. The elevator system prototype is constructed with three floors to elevate a maximum load of 6kg. Programmable Logic Controller (PLC) of (LS\GLOFA-G7M-DR30U) series with (16) inputs and (12) outputs programmed with Ladder diagram software is used for the fully automated the elevator system. The idea of the proposed elevator system may be predicted to be widely spread in the low-rise residential buildings

Monikoristen hissien kehityssuunnat

While the world’s population moves to cities and the height of the building base rises, the limitations of elevator technology become more significant. The greatest problem of the modern elevator is the required space. Related to this is the majority of the hoistway volume, which is not in active use on a traditional single-car elevator. This inefficiency results in a large loss of usable floor space, especially in high-rise buildings. This thesis discusses attempts to solve the inefficiency problem by installing multiple elevator cars into a single hoistway. The elevators with multiple cars have existed since the 19th century, and various development paths have been present, but currently only one product is commercially available. The thesis presents design challenges and solutions that are characteristic for multi-car elevator concepts. While the current elevators move only vertically, horizontal car movement can be considered to be a mandatory feature to achieve the expected capacity of a future multi-car elevator. The horizontal movement is required to enable possibility for cars to pass each other. Most patents on multi-car elevator concepts are based on conventional roped hoisting equipment. However, linear electric motors are considered to be a promising technology that could provide propulsion more easily in all directions. In theory, a “vertical train” –like elevator concept could have a flexible number of cars in the same hoistway. The additional cars would reduce the number of hoistways and enhance the usability of the system in different installation heights. Still today, only a few of the self-propelled elevator concepts have survived beyond the prototype stage. Three common challenges with the concepts include power-transfer, safety, and costs.Maailman väestön muuttaessa kaupunkeihin ja rakennuskannan kohotessa yhä korkeammaksi, ovat hissitekniikan rajoitukset käyneet entistä merkittävämmiksi. Nykyaikaisen hissin suurin ongelma on sen vaatima tila. Tilantarve on seurausta siitä, että tavanomaisessa köysihissikonstruktiossa vain pieni osa hissikuilun kokonaistilavuudesta on aktiivisessa käytössä. Erityisesti korkeissa kiinteistöissä mainittu tehottomuus aiheuttaa merkittäviä menetyksiä hyödynnettävässä lattiapinta-alassa. Tämä diplomityö käsittelee keinoja ratkaista edellä mainittu hissien tilankäytön tehottomuus asentamalla useita hissikoreja samaan hissikuiluun. Tällaisia hissejä on ollut olemassa jo 1800-luvulta lähtien, ja sen seurauksena on havaittavissa useita monikoriseen hissiin johtavia kehityspolkuja, mutta silti nykyisin saatavilla on vain yksi useampaa koria samassa kuilussa hyödyntävä kaupallinen tuote. Työ esittelee monikorisille hisseille ominaisia suunnittelun haasteita ja ratkaisuja. Siinä missä perinteinen hissi liikuttaa koria vain pystysuorasti, voidaan vaakasuuntaista liikkumista pitää lähes välttämättömänä ominaisuutena monikoriselle hissille halutun tehokkuuden saavuttamiseksi. Vaakaliike tarvitaan hissikorien keskinäisen ohittamisen mahdollistamiseksi. Suurin osa monikorisia hissejä käsittelevistä patenteista perustuu tavanomaisiin köydellisiin nostolaitteisiin, mutta siitä huolimatta lineaarinen sähkömoottori voidaan nähdä lupaavampana käyttölaitetekniikkana joka tarjoaisi yksinkertaisemmilla ratkaisulla työntövoimaa kaikkiin suuntiin. Teoriassa ”pystysuuntainen juna” –tyyppinen hissikonsepti voisi johtaa ratkaisuihin joissa hissikoreja saataisiin kuiluun tarpeen mukainen määrä. Lisätyt korit voisivat vähentää hissikuilujen lukumäärää ja parantaa järjestelmän käytettävyyttä erikorkuisissa rakennuksissa. Tähän asti vain muutama itsestään kulkeva hissikonsepti on selvinnyt prototyyppiastetta pidemmälle. Konseptien kolme yleisintä haastetta liittyvät energiansiirtoon, turvallisuuteen ja kustannuksiin

Electrified Powertrains for a Sustainable Mobility: Topologies, Design and Integrated Energy Management Strategies

This Special Issue was intended to contribute to the sustainable mobility agenda through enhanced scientific and multi-disciplinary knowledge to investigate concerns and real possibilities in the achievement of a greener mobility and to support the debate between industry and academic researchers, providing an interesting overview on new needs and investigation topics required for future developments