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The thermal management of electric machines is investigated with the application of techniques to a Switched Reluctance Machine and a high-speed Switched Reluctance Machine. Two novel concepts for said management of a Switched Reluctance Machine are proposed and developed: Inter-Laminate Cooling and a Continuous Toroidal Winding. The Inter-Laminate Cooling concept is developed with application to an iron core inductor which serves as a proxy for the electric machine. The experimental results confirmed the capability of the method, expressed by the effectiveness, which defines the performance measure of the applied cooling method; a concept which itself is equally applicable to other cooling methods that may be applied to any electric machine. The effectiveness also describes the gain in allowable input power to the machine which is realized to reach the same thermal limit versus the case without Inter-Laminate Cooling. The Inter-Laminate Cooling was not applied in experimental test to a Switched Reluctance Machine due to the present economic and fabrication limitations. The Continuous Toroidal Winding concept, originally conceived to permit the consideration of a fluid capillary core type of winding to enhance machine cooling, is developed to allow for peripheral cooling of the machine windings and end windings. The Continuous Toroidal Winding version of the Switched Reluctance Machine is investigated for both its thermal and electrical performance in the context of a machine that is equivalent electromagnetically to its conventional counterpart. The Continuous Toroidal Winding Switched Reluctance Machine was found to perform thermally as tested, in a manner superior to that of the conventional machine where the Toroidal machine was simulated and researched at an equivalent level of operation to the conventional machine. The electrical performance of the Toroidal Switched Reluctance Machine although supportive of the simulation analysis used to develop the machine, was not fully conclusive. This may have been due to problematic iron cores used in the construction of the experimental machines. The application of the Inter-Laminate Cooling method to a Switched Reluctance Machine is considered on an analytical basis for the special case of a High Speed Switched Reluctance Machine and found to be of net positive benefit as the machine’s iron losses are dominant over its copper losses. Application of the Inter-Laminate Cooling method to a lower speed machine, whilst beneficial, is not sufficient to significantly impact the temperature of the machine’s windings such that it would offset the loss of specific torque and power. As such, Inter-Laminate Cooling is only applicable where the net benefit is positive overall; in that the gain in input power realized is sufficient to overcome the loss of specific power and torque which will occur due to the increased machine volume. The “effectiveness” and “gain” approach for the evaluation of cooling methods applied to electric machines is a concept which should be adopted to aid in the comparative understanding of the performance of myriad different cooling methods being applied to electric machines both in research and practice, of which there is only minimal understanding. / Thesis / Doctor of Philosophy (PhD)

With the unstable cost and supply of rare earth materials used in permanent magnet electric machines, many alternative machine types are being studied which are suitable for different applications. The focus of this thesis is the design of a novel 6/14 switched reluctance machine which can be fitted in a residential heating, ventilation, and air-conditioning (HVAC) application based on measured performance characteristics of an existing surface mount permanent-magnet synchronous (SMPS) machine. Residential electric motor applications are reviewed and in particular - furnace blower motor appliances. The fundamentals of switched reluctance machines are discussed, including the mechanism, operation, and control strategy. A SMPS motor which is commercially available for retrofitting into residential HVAC systems is analyzed to find its performance characteristics through disassembly, inspection, and dynamometer bench testing. The design of a novel 6/14 SRM optimization process is outlined to investigate the effect of changing the geometry values within the motor on the performance characteristics, while keeping within the size constraints of the original motor. A novel 6/14 SRM design is presented which is capable of achieving the target goals in the desired operating conditions. Further suitability testing is performed in terms of thermal analysis of the motor in the peak and continuous operating condition and mechanical stress analysis of the rotor under various rotational speeds. The full CAD assembly of the motor is designed including components from the original SMPS motor to allow for fitting in the same HVAC application. / Thesis / Master of Applied Science (MASc) / With the unstable cost and supply of rare earth materials used in permanent magnet electric motors, many alternative machine types are being studied which are suitable for different applications. The focus of this thesis is the design of a novel 6/14 switched reluctance machine which can be fitted in a residential heating, ventilation, and air-conditioning (HVAC) application based on measured performance characteristics of an existing surface mount permanent-magnet synchronous (SMPS) machine. Switched reluctance machines have a number of benefits over permanent magnet machines including that they do not have permanent magnets, are less sensitive to high heat scenarios, have lower manufacturing costs, are more robust, and are generally capable of higher operating speeds. Residential electric motor applications are reviewed and in particular - furnace blower motor appliances. The fundamentals of switched reluctance machines are discussed, including the mechanism, operation, and control strategy. A SMPS motor which is commercially available for retrofitting into residential furnace systems is analyzed to find its performance characteristics through disassembly, inspection, and dynamometer bench testing. The design of a novel 6/14 SRM optimization process is outlined to investigate the effect of changing the geometry values within the motor on the performance characteristics, while keeping within the size constraints of the original motor. A novel 6/14 SRM design is presented which is capable of achieving the target goals in the desired operating conditions. Further suitability testing is performed in terms of thermal analysis of the motor in the peak and continuous operating condition and mechanical stress analysis of the rotor under various rotational speeds. The full 3D CAD assembly model of the motor is designed including components from the original SMPS motor to allow for fitting in the same HVAC application.

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Yes / This paper introduces a hybrid dynamic modelling approach for the prediction of NOx emissions for a Diesel engine, based on a multi-physics simulation platform coupling a 1-D air path model (GT-Suite) with in-cylinder combustion model (CMCL Stochastic Reactor Model Engine Suite). The key motivation for this research was the requirement to establish a real time stochastic simulation capability for emissions predictions early in engine development, which required the replacement of the slow combustion chemistry solver (SRM) with an appropriate surrogate model. The novelty of the approach in this research is the introduction of a hybrid approach to metamodeling that combines dynamic experiments for the gas path model with a zonal optimal space-filling design of experiments (DoEs) for the combustion model. The dynamic experiments run on the virtual Diesel engine model (GT- Suite) was used to fit a dynamic model for the parameters required as input to the SRM. Optimal Latin Hypercubes (OLH) DoE run on the SRM model was used to fit a response surface model for the NOx emissions. This surrogate NOx model was then used to replace the computationally expensive SRM simulation, enabling real time simulations of transient drive cycles to be executed. The performance of the proposed approach was validated on a simulated NEDC drive cycle against experimental data collected for the engine case study, which proved the capability of methodology to capture the transient trends for the NOx emissions. The significance of this work is that it provided an efficient approach to the development of a global model with real time transient modelling capability based on the integration of dynamic and local DoE metamodeling experiments.

Switched Reluctance Machines (SRMs) are receiving significant attention from industries in the last decade. They are extremely inexpensive, reliable and weigh less than other machines of comparable power outputs. Although the design principles of the machine are available as a concatenation of many different sources, the need for a unified, step-by-step design procedure from first principles of electromagnetics is an absolute requirement. This dissertation discusses a procedure that can be applied by engineers with a basic background in electromagnetics. Subsequent to the design of the machine, existing finite element software can do the analysis of the machine. However, this is a laborious process and the need for an analytical method is preferable to verify the design procedure before the final verification by finite elements. The analytical procedure as well as a procedure to calculate iron losses is also developed in this dissertation. A prototype machine has been developed as an example of the design process and an existing prototype is analyzed to verify the analysis procedure. The similarities between the SRM and the Permanent Magnet Brushless DC Machine (PMDBC) beg the consideration of the development of a converter that can be used to drive either machine. One such converter has been developed in this dissertation. The design of the drive for both the machines is seen to be very similar. As a consequence, a universal controller that can be used to operate both machines has been developed and implemented with a DSP. Simulations and experimental correlation for both drives have been presented. / Ph. D.

As traditional control schemes, open-loop Hysteresis and closed-loop pulse-width-modulation (PWM) have been used for the switched reluctance motor (SRM) current controller. The Hysteresis controller induces large unpleasant audible noises because it needs to vary the switching frequency to maintain constant Hysteresis current band. In contract, the PWM controller is very quiet but difficult to design proper gains and control bandwidth due to the nonlinear nature of the SRM. In this thesis, the ac small signal modeling technique is proposed for linearization of the SRM model such that a conventional PI controller can be designed accordingly for the PWM current controller. With the linearized SRM model, the duty-cycle to output transfer function can be derived, and the controller can be designed with sufficient stability margins. The proposed PWM controller has been simulated to compare the performance against the conventional Hysteresis controller based system. It was found that through the frequency spectrum analysis, the noise spectra in audible range disappeared with the fixed switching frequency PWM controller, but was pronounced with the conventional Hysteresis controller. A hardware prototype is then implemented with digital signal processor to verify the quiet nature of the PWM controller when running at 20 kHz switching frequency. The experimental results also indicate a stable current loop operation. / Master of Science

One of the most important attribute a cloud service provider (CSP) offers their customers through their cloud services is scalability. Scalability gives customers the ability to vary the amount of capacity when required. A cloud service can be divided in three service layers, Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). Scalability of a certain service depends on software licenses on these layers. When a customer wants to increase the capacity it will be determined by the CSP's licenses bought from its suppliers in advance. If a CSP scales up more than what was agreed on, then there is a risk that the CSP needs to pay a penalty fee to the supplier. If the CSP invests in too many licenses that does not get utilized, then it will be an investment loss. A second challenge with software licensing is when a customer outsources their applications to the CSP’s platform. As each application comes with a set of licenses, there is a certain level of scalability that cannot be exceeded. If a customer wants the CSP scale up more than usual for an application then the customer need to inform the vendors. However, a common misunderstanding is that the customer expects the CSP to notify the vendor. Then there is a risk that the vendor never gets notified and the customer is in danger of paying a penalty fee. This in turn hurts the CSP’s relationship with the customer. The recommendation to the CSP under study is to create a successful customer relationship management (CRM) and a supplier relationship management (SRM). By creating a CRM with the customer will minimize the occurring misunderstandings and highlight the responsibilities when a customer outsources an application to the CSP. By creating a SRM with the supplier will help the CSP to maintain a flexible paying method that they have with a certain supplier. Furthermore, it will set an example to the remaining suppliers to change their inflexible paying method. By achieving a flexible payment method with the suppliers will make it easier for the CSP to find equilibrium between scalability and licenses. / Ett av de viktigaste attributen en molnleverantör (CSP) erbjuder sina kunder genom sina molntjänster är skalbarhet. Skalbarheten ger kunden möjligheten att variera mängden kapacitet efter behov. En molntjänst kan delas in i tre serviceskikter, Infrastruktur-as-a-Service (IaaS), Platform-as-a-Service (PaaS) och Software-as-a-Service (SaaS). Skalbarheten av en viss service beror på mjukvarulicenser på dessa skikt. När en kund vill öka kapaciteten bestäms detta av CSP:s förhandsköpta licenser från sina leverantörer. Om en CSP skalar upp mer än vad som avtalats, finns det en risk att CSP:n måste betala en straffavgift till leverantören. Investerar CSP i alltför många licenser som inte utnyttjas, blir det en investeringsförlust. En annan utmaning med mjukvarulicenser uppstår när en kund lägger ut sina applikationer på CSP:s plattform. Eftersom varje applikation levereras med en uppsättning av licenser, finns det en bestämd nivå av skalbarhet som inte kan överskridas. Om en kund vill att CSP:n ska skala upp mer än vanligt för en applikation, måste kunden informera applikationsförsäljaren själv. Dock sker det en missuppfattning då kunden förväntar sig att CSP:n ska meddela säljaren om detta. Det finns en risk att säljaren aldrig blir informerad och kunden hamnar i stor risk för att betala en straffavgift. Detta i sin tur skadar CSP:s relation med kunden. Rekommendationen till CSP:n är att skapa en framgångsrik kundrelationshantering (CRM) och leverantörrelationshantering (SRM). Genom att skapa en CRM med kunden kan förekommande missförstånd minimeras och belysa ansvarsområden som råder när en kund lägger ut sin applikation hos CSP:n. Genom att skapa en SRM med leverantörerna kommer det att hjälpa CSP:n att upprätthålla en flexibel betalmetod som de har med en viss leverantör. Dessutom kommer det att vara ett föredöme för de övriga leverantörerna att ändra sin icke flexibla betalningsmetod. Genom att uppnå en mer flexibel betalningsmetod med leverantörerna kommer det att bli enklare för en CSP att hitta en balans mellan skalbarhet och licenser.

Neural networks have become increasingly adopted in society over the last few years. As neural networks consume a lot of energy to train, reducing the energy consumption of these networks is desirable from an environmental perspective. Spiking neural network is a type of neural network inspired by the human brain which is significantly more energy efficient than traditional neural networks. However, there is little research about how the hyper parameters of these networks affect the relationship between accuracy and energy. The aim of this report is therefore to analyse this relationship. To do this, we measure the energy usage of training several different spiking network models. The results of this study shows that the choice of hyper-parameters in a neural network does affect the efficiency of the network. While correlation between any individual factors and energy consumption is inconclusive, this work could be used as a springboard for further research in this area. / Under de senaste åren har neuronnät blivit allt vanligare i samhället. Eftersom neuronnät förbrukar mycket energi för att träna dem är det önskvärt ur miljösynpunkt att minska energiförbrukningen för dessa nätverk. Spikande neuronnät är en typ av neuronnät inspirerade av den mänskliga hjärnan som är betydligt mer energieffektivt än traditionella neuronnät. Det finns dock lite forskning om hur hyperparametrarna i dessa nätverk påverkar sambandet mellan noggrannhet och energi. Syftet med denna rapport är därför att analysera detta samband. För att göra detta mäter vi energiförbrukningen vid träning av flera olika modeller av spikande neuronnät-modeller. Resultaten av denna studie visar att valet av hyperparametrar i ett neuronnät påverkar nätverkets effektivitet. Även om korrelationen mellan enskilda faktorer och energiförbrukning inte är entydig kan detta arbete användas som en startpunkt för ytterligare forskning inom detta område.