One of the goals of ABB AB is to develop highly efficient electric motors for traction application. The demand for traction motors is increasing due to the rise in electric vehicles sale and railway locomotive engines. Highly efficient traction motors will assist in reducing the pollution caused by fossil fuels and help make the earth a better place to live by leveraging sustainable energy. The electrical and mechanical characteristics of electric motors are measured and analyzed in the lab. The measured data of the electric motor in the lab are analyzed using the conventional way. One of the significant challenges in a conventional way is to isolate the system with various limitations, and it offers very few choices for measurement. The data management of measured observation readings is affected severely due to this, and it is then risky to determine and analyze the characteristics of electric motors. The first aim is to develop an automatic data processing algorithm for the measurement data collected from the specific setup of the electrical machine. The data processing is done using the MATLAB tool. Statistical methods such as mean, median, moving mean, moving median, Gaussian model for handling missing data, outliers, and data smoothing methods have been implemented to get accurately measured datasets as a part of this thesis. In addition, a study of vibrational analysis of the test bench assembly was performed for the traction motor. The natural frequency of test bench assembly is computed on the Finite Element Method (FEM) tool. All the natural frequencies of the test bench assembly with the traction motor are analyzed, and some of them were closed to the excitation frequency of the traction motor.  This study found that the resonance frequency of the test bench assembly has to be prevented while operating the traction motor during lab to strengthen the life of the test bench.

Within the framework of this thesis, the electron beam melting of pure copper for the purpose of producing electrical windings was examined. The conventional manufacturing process of copper windings was investigated, and the potential advantages offered by the design freedom inherent in the electron beam melting process were explored. A comprehensive parameter study was conducted to optimize the existing production parameters for the electron beam melting of pure copper, with a specific focus on achieving the desired material properties suitable for electric motor windings. Moreover, according to additive manufacturing possibilities, conceptual winding models were developed and subsequently were fabricated in a laboratory setting using electron beam melting. The investigation revealed a notable correlation between the achievable wall thickness and the focus offset. A focused electron beam, which was achieved with a focus offset of 17 mA, allowed for the production of thinner walls with reduced surface roughness. Additionally, the study highlighted that the density of the manufactured parts decreased as the hatch offset increased, particularly posing a more critical impact on smaller cross-sectional areas than larger ones. Furthermore, implementing a double-scanned contour for the hatch contributed to diminishing roughness while simultaneously increasing the maximum density to 99.6 %. Influencing the electrical conductivity of printed copper samples through heat treatment was successfully demonstrated, resulting in a conductivity of 91.7% ± 1.8% IACS post-heat treatment. / Inom ramen för denna avhandling undersöktes elektronstrålesmältningen av ren koppar i syfte att producera elektriska lindningar. Den konventionella tillverkningsprocessen av kopparlindningar undersöktes, och de potentiella fördelarna som erbjuds av designfriheten som är inneboende i elektronstrålesmältningsprocessen undersöktes. En omfattande parameterstudie genomfördes för att optimera befintliga produktionsparametrar för elektronstrålesmältning av ren koppar, med särskilt fokus på att uppnå önskade materialegenskaper lämpliga för elmotorlindningar. Dessutom, i enlighet med additiva tillverkningsmöjligheter, utvecklades konceptuella lindningsmodeller och tillverkades därefter i laboratoriemiljö med användning av elektronstrålesmältning. Undersökningen avslöjade en anmärkningsvärd korrelation mellan den möjliga väggtjockleken och fokusförskjutningen. En fokuserad elektronstråle, som uppnåddes med en fokusförskjutning på 17 mA, möjliggjorde produktion av tunnare väggar med minskad ytjämnhet. Dessutom visade studien att densiteten hos de tillverkade delarna minskade när avståndet mellan smältlinjerna ökade, vilket i synnerhet innebar en mer kritisk påverkan på mindre tvärsnittsareor än större. Dessutom bidrog implementeringen av en dubbelskannad kontur för luckan till att minska grovheten samtidigt som den maximala densiteten ökade till 99,6 %. Att påverka den elektriska ledningsförmågan hos tryckta kopparprover genom värmebehandling demonstrerades framgångsrikt, vilket resulterade i en ledningsförmåga på 91,7 % ± 1,8 % IACS efter värmebehandling.

Relevance of this research is conditioned by necessity of increasingmetalworking machines efficiency in modern machinery building. One of the main constructive elements of gear milling machines is mechanical gear train (speed gear train, feed gear train, dividing gear train, differential gear train). The adjustment of all these shaping moves is important objective. Though mechanical gear trains do not provide high tooling precision.That’s why precision can be increased by developing ways of replacing mechanical gear trains by hydraulic and electronic analogs. These ways were poorly considered before. Goal of the work: analyzing of existing principal gear milling machine schemes, analyzing of possible ways of shaping moves electronic adjustment, descrying of various frequent divisor structures. Calculation unevennessof impulses following for divisors, that work in different codes and improving schemes of machines with electric step motor and adjustable electric motor by way of increasing tooling precision. Master’s dissertation consists of 6 chapters: Chapter 1: Modern gear milling machines principal schemes. This chapter describes function of gear trains, structure of cutting moves in gear milling and schemes of existing gear milling machines with mechanical and electronic gear trains. Chapter 2: Analysis of ways and tools of electronic (“Non-gear-train”) adjustment of machine’s shaping moves. This chapter describes ways of coordinating an adjustable electronic motor and electronic step motor, ways of coordinating two adjustable electronic motors. Chapter 3: modern constructions of impulse frequency divisors. Schemes andfunctioning of divisors. This chapter analyze various schemes of frequency divisors, ways of divisor selecting for gear milling machine, calculating the unevenness of impulses, transferring with divisors for various codes. Chapter 4: Improvement of gear milling machines with electric step motor Suggestion of improved kinematic schemes for electric step motor milling machines. Chapter 5: Improvement in schemes of gear milling machines with adjustable electric motor. Suggestion of improved kinematic schemes for adjustable electric motor milling machines. Chapter 6: Work out of technical proposal for gear milling machine with adjustable electric motor. Chapter contains selection of electric motor for chosen kinematic scheme with electronic gear train, kinematic and robustness calculation, comparison of mechanical and electronic gears’ precision. Master’s dissertation consist of 128 pages, containing demonstrational materials, calculations and text description, and 17 graphic documents. / Актуальность темы исследования обусловлена необходимостью повышения эффективности металлорежущих станков в современном машиностроении. Одними из основных конструктивных элементов зубофрезерного станка являются механические гитары (скоростей, подач, деления, дифференциала). Важной задачей является согласовать всеэти формообразующие движения. Но механические гитары не обеспечивают высокой точности обработки. Поэтому были разработаны способы повышения точности путем замены механических гитар гидравлическими и электронными. Ранее эти способы были рассмотрены поверхностно. Цель работы: проведение анализа существующих принципиальных схем зубофрезерных станков, анализ возможных способов электронного согласования формообразующих движений, рассмотрение различных конструкций делителей частоты, расчет неравномерности следования импульсов для делителей, работающих в различных кодах, и совершенствование схем станков с шаговым и регулируемым электроприводами для повышения точности обработки. Магистерская диссертация состоит из 6 глав: Глава 1: Принципиальные схемы современных зубофрезерных станков В главе рассматривается назначение гитар, структура рабочего движения при зубофрезеровании, а также существующие кинематические схемы зубофрезерных станков с механическими и электронными гитарами. Глава 2: Анализ способов и средств электронного («безгитарного») согласования формообразующих движений в станке В главе описываются способы согласования работы регулируемого и шагового приводов, и согласование работы двух регулируемых приводов. Глава 3: Современные конструкции делителей частоты импульсов, их устройство и работа В главе анализируются различные конструкции делителей частоты, также производится выбор делителя, применительно к зубофрезерному станку. Производится расчет неравномерности следования импульсов, передаваемых через делители для различных кодов. Глава 4: Совершенствование зубофрезерных станков с шаговым электроприводом Предлагаются усовершенствованные кинематические схемы станков с шаговыми электроприводами. Глава 5: Совершенствование схем зубофрезерных станков с регулируемыми электроприводами Предлагаются усовершенствованные кинематические схемы станков с регулируемыми электроприводами. Глава 6: Разработка технического предложения зубофрезерного станка с регулируемыми электроприводами В главе выбирается электродвигатель для выбранной кинематической схемы с электронной гитарой, производится кинематический и прочностной расчет и сравниваются по точности механическая и электронная гитары. Магистерская диссертация выполнена на 128 страницах, содержащих демонстрационные материалы, расчеты и описание, и включает 17 графических документов.

MULTILEVEL inverters are the preferred choice of converters for electronic power conversion for high power applications. They are gaining popularity in variety of industrial applications including electric motor drives, transportation, energy management, transmission and distribution of power. A large portion of energy conversion systems comprises of multilevel inverter fed induction motor drives. The multilevel inverters are ideal for such applications, since the switching frequency of the devices can be kept low. In conventional two level inverters, to get nearly sinusoidal phase current waveform, the switching frequency of the inverter is increased and the harmonics in the currents are pushed higher in the frequency spectrum to reduce the size and cost of the filters. But higher switching frequency has its own drawbacks – in particular for medium voltage, high power applications. They cause large dv_/ dt stresses on the motor terminals and the switching devices, leading to increased electromagnetic interference (EMI) problems and higher switching losses. Harmonics in the motor currents can further be minimized by adopting dodecagonal voltage space vector (SV) switching (12-sided polygon). In case of dodecagonal SV switching, the fifth and seventh order (6n , 1, n = odd) harmonics are completely eliminated for the full modulation range including over modulation and twelve step operation in the motor phase voltages and currents. In addition to low order harmonic current suppression, the linear modulation range for dodecagonal SV switching is also more by 6% when compared to that of the conventional hexagonal SV switching. The dodecagonal voltage SV structure is made possible by connecting two inverters with DC-link voltages Vd and 0:366Vd on either side of an open-end winding induction motor. The dodecagonal space vector switching can be used to produce better quality phase voltage and current waveforms and overcome the problem of low order fifth and seventh harmonic currents and to improve the range for linear modulation while reducing the switching frequency of the inverters when compared to that of the conventional hexagonal space vector based inverters. This thesis focuses on three aspects of multilevel dodecagonal space vector structures (i) Two new power circuit topologies that generate a multilevel dodecagonal voltage space vector structure with symmetric triangles, (ii) A multilevel dodecagonal SV structure with nineteen concentric dodecagons, (iii) Pulse width modulation (PWM) timing calculation methods for a general N-level dodecagonal SV structure. (i) Two new power circuit topologies capable of generating multilevel dodecagonal voltage space vector structure with symmetric triangles with minimum number of DC link power supplies and floating capacitor H-bridges are proposed. The first power topology is composed of two hybrid cascaded five level inverters connected to either side of an open end winding induction machine. Each inverter consists of a three level neutral point clamped (NPC) inverter, cascaded with an isolated capacitor fed H-bridge making it a five level inverter. The second topology is a hybrid topology for a normal induction motor (star or delta connected), where the power is fed to the motor only from one side. The proposed scheme retains all the advantages of multilevel topologies as well the advantages of the dodecagonal voltage space vector structure. Both topologies have inherent capacitor balancing for floating H-bridges for all modulation indices including transient operations. The proposed topologies do not require any pre-charging circuitry for startup. PWM timing calculation method for space vector modulation is also explored in this chapter. Due to the symmetric arrangement of congruent triangles within the voltage space vector structure, the timing computation requires only the sampled reference values and does not require any iterative searching, off-line computation, look-up tables or angle estimation. Experimental results for steady state operation and transient operation are also presented to validate the proposed concept. (ii) A multilevel dodecagonal voltage space vector structure with nineteen concentric do-decagons is proposed for the first time. This space vector structure is achieved by connecting two sets of asymmetric hybrid five level inverters on either side of an open-end winding induction motor. The dodecagonal structure is made possible by proper selection of DC-link voltages and switching states of the inverters. In addition to that, a generic and simple method for calculation of PWM timings using only sampled reference values (v and v ) is proposed. This enables the scheme to be used for any closed loop application like vector control. Also, a new switching technique is proposed which ensures minimum switching while eliminating the fifth and seventh order harmonics and suppressing the eleventh and thirteenth harmonics, eliminating the need for bulky filters. The motor phase voltage is a 24-stepped waveform for the entire modulation range thereby reducing the number of switchings of the individual inverter modules. Experimental results for steady state operation, transient operation including start-up have been presented and the results of Fast Fourier Transform (FFT) analysis is also presented for validating the proposed concept. (iii) A method to obtain PWM timings for a general N-level dodecagonal voltage space vector structure using only sampled reference values is proposed. Typical methods that are used to find PWM timings for dodecagonal SV structures use modulation index and the reference vector angle, to get the timings T1 and T2 using trigonometric calculations. This method requires look-up tables and is difficult to implement in closed loop systems. The proposed method requires only two additions to compute these timings. For multilevel case, typical iterative methods need timing calculations (matrix multiplications) to be performed for each triangle. The proposed method is generic and can be extended to any number of levels with symmetric structures and does not require any iterative searching for locating the triangle in which the tip of the reference vector lies. The algorithm outputs the triangle number and the PWM timing values of T0, T1 and T2 which can be set as the compare values for any carrier based PWM module to obtain space vector PWM like switching sequences. Simulation and experimental results for steady state and transient conditions have been presented to validate the proposed method. A 3.7 kW, 415 V, 50 Hz, 4-pole open-end winding induction motor was used for the experimental studies. The semiconductor switches that were used to realize the power circuit for the experiment were 75 A, 1200 V insulated-gate bipolar transistor (IGBT) half-bridge modules (SKM75GB12T4). Opto-isolated gate drivers with desaturation protection (M57962L) were used to drive the IGBTs. For the speed control and PWM timing computation a digital signal processor (DSP-TMS320F28335) with a clock frequency of 150 MHz was used. For modulation frequencies 10 Hz and below, a constant sampling frequency of 1 kHz was used as the frequency modulation ratio is high. For modulation frequencies above 10 Hz, synchronous PWM strategy was used. The time duration Ts is the sampling interval for which the timings T1 , T2 and T0 are calculated. As in the case of any synchronous PWM method, the duration of sampling time (Ts) is a function of the fundamental frequency of the modulating signal. In this case, Ts = 1_.fm • 12n) sec. where fm is fundamental frequency in Hertz and ‘n’ is the number of samples per 30ý dodecagonal sector. The PWM timings and the triangle data (from the DSP) is fed to field programmable gate array (FPGA) (SPARTAN XC3S200) clocked at 50 MHz where the actual gating pulses are generated. The capacitor balancing algorithm and the dead-time modules were implemented within FPGA. No external hardware was used for generation of dead-time. The dead-time block generates a constant dead-time of 2 s for all the switches. Extensive testing was done for steady state operations and transient operations including quick acceleration and start-up to validate the proposed concepts. With the advantages like extension of linear modulation range, elimination of fifth and seventh harmonics in phase voltages and currents for the full modulation range, suppression of eleventh and thirteenth harmonics in phase voltages and currents, reduced device voltage ratings, lesser dv_dt stresses on devices and motor phase windings, lower switching frequency, inherent cascaded H-bridge (CHB) capacitor balancing, the proposed space vector structures, the inverter power circuit topologies, the switching techniques and the PWM timing calculation methods can be considered as viable schemes for medium voltage, high power motor drive applications.

I en tid kännetecknat av en strävan efter ett mer hållbart samhälle, med utformade långsiktiga klimatmål för förnyelsebara energikällor och minskade utsläpp, arbetar fordonsutvecklare med att ta fram alternativ till förbränningsmotorer. För att nå satta klimatmål och samtidigt förbättra arbetsmiljön med minskat buller anses en elektrisk drivlina som ett troligt alternativ. För tunga fordon såsom lastbilar som ofta utrustas med tillsatsutrustning som kranar, tippbara flak eller cementroterare är beroende av ett kraftuttag för att driva hydraulpumpar och generatorer. Vid en omställning till elektrisk drivlina är det inte längre säkert att möjligheten kvarstår att ta kraft från drivlinan. Detta har lett till en efterfrågan på elektriskt separat drivna kraftuttag uppstått på marknaden. Syftet med denna studie är att undersöka och få en förståelse för inom vilket effektområde och vilken typ av elektrisk motor som är bäst lämpad för att separat driva ett kraftuttag. Målet är att med denna kunskap utveckla en modell som förenklar valet av lämplig elektrisk motor för ett givet fall av kraftuttag. Modellen testas med en effekt på 60 kW vilket resulterade i att en lågvarvig axial flux BLDC-motor anses bäst lämpad. Detta då en lågvarvig elektrisk motor kräver lägre utväxling för att uppfylla krävt vridmoment, vilket ger en lägre totalvikt. Totalvikt för testad effekt hamnar på 78,6 kg, vilket är tre gånger det funktionella kravet. Studien ger en indikation på att det med givna krav enbart är försvarbart att driva kraftuttag med separata elektriska motorer vid låga effekter, runt 10 kW. / In a time characterized by an endeavor for a more sustainable society. With formulated long-term climate targets for renewable energy sources and reduced emissions, vehicle developers are working to develop alternatives to internal combustion engines. In order to achieve set climate targets and at the same time improve the working environment with reduced noise, an electric driveline is considered a likely alternative. For heavy vehicles such as trucks that are often equipped with auxiliary accessories such as cranes, tipper trucks or cement rotators are dependent on a power take-off to drive hydraulic pumps and generators. When switching to an electric driveline, it is no longer certain that the possibility remains to take power from the driveline. This has led to a demand for electrically driven power take-offs on the market. The purpose of this study is to investigate and gain an understanding of the power range and type of electric motor that is best suited to drive a power take-off separately. The goal is to use this knowledge to develop a model that simplifies the choice of a suitable electric motor for a given case of power take-off. The model is tested with an output of 60 kW, which resulted in a low-speed axial flux BLDC-motor being considered best suited. This is because a low-speed electrical motor requires a lower gear ratio to meet the required torque, which gives a lower total weight. The total weight for the tested effect ends up at 78,8 kg, which is three times the functional requirement. The study gives an indication that with given requirements it is only justified to operate power take-offs with separate electric motors at low powers, around 10 kW.

Model predictive control is a popular research focus in electric motor control as it allows designers to specify optimization goals and exhibits fast transient response. Availability of faster and more affordable computers makes it possible to implement these algorithms in real-time. Real-time implementation is not without challenges however as these algorithms exhibit high computational complexity. Field-programmable gate arrays are a potential solution to the high computational requirements. However, they can be time-consuming to develop for. In this thesis, we present a methodology that reduces the size and development time of field-programmable gate array based fixed-point model predictive motor controllers using automated numerical analysis, optimization and code generation. The methods can be applied to other domains where model predictive control is used. Here, we demonstrate the benefits of our methodology by using it to build a motor controller at various sampling rates for an interior permanent magnet synchronous motor, tested in simulation at up to 125 kHz. Performance is then evaluated on a physical test bench with sampling rates up to 35 kHz, limited by the inverter. Our results show that the low latency achievable in our design allows for the exclusion of delay compensation common in other implementations and that automated reduction of numerical precision can allow the controller design to be compacted. / Thesis / Master of Applied Science (MASc)

This master’s thesis deals with a new design of bar screens. The goal was to come up with an alternative design to already existing device by INKOS a. s. In the first part, there is a summary of various machines working in similiar conditions. The insights gained by this research influenced the design of the new device. It utilizes well proven solutions from previous projects, but some of these were reworked and a few new functions were added. Second part of the thesis describes the analytical solutions, which were used to determine the forces in the assembly during the operation of the device. Based on the results of these calculations, a strength analysis of important components was performed using the finite element method. The result of this thesis is the design and optimization of new bar screens, including engineering drawings and tools for its further development.