Desenvolvimento de uma máquina síncrona trifásica com ímãs de Nd-Fe-B e núcleo do rotor a partir de ferro sinterizado para aplicação em aerogeradores de 7,5 kW, verificando a viabilidade do protótipo. Partindo de um projeto anteriormente desenvolvido, foi realizada alteração no ângulo das chapas do estator em 10º, com o intuito de minimizar o efeito de correntes parasitas, sendo esse um dos fatores que influenciam os resultados. Para avaliação de desempenho, foi utilizada uma bancada de testes composta de analisador de energia, sensor de torque e instrumentos de medição, sendo o acionamento do protótipo realizado através de um motor de indução controlado por um inversor de frequência. Entre os resultados encontrados, foi constatada a presença de harmônicas que impactam sobre os valores obtidos do protótipo. Os testes realizados, de simulação e parâmetros elétricos, indicaram resultados apropriados ao desempenho de uma máquina elétrica trifásica, porém mostram-se necessárias alterações para um melhor desempenho do protótipo. / Development of a three-phase synchronous machine with Nd-Fe-B magnets and rotor core from sintered iron for application in 7.5 kW wind turbines, verifying the feasibility of the prototype. Starting from a previously developed design, a change in the angle of the stator plates was made in 10º, in order to minimize the effect of the parasite currents, being one of the factors that influence the results. For performance evaluation, a test bench composed of energy analyzer, torque sensor and measuring instruments was used, and the drive of the prototype was carried out through an induction motor controlled by a frequency inverter. Among the results found, it was verified the presence of harmonics that impact on the values obtained from the prototype. The tests performed, simulation and electrical parameters, indicated results appropriate to the performance of a three-phase electric machine, however changes are needed for a better performance of the prototype.

Desenvolvimento de uma máquina síncrona trifásica com ímãs de Nd-Fe-B e núcleo do rotor a partir de ferro sinterizado para aplicação em aerogeradores de 7,5 kW, verificando a viabilidade do protótipo. Partindo de um projeto anteriormente desenvolvido, foi realizada alteração no ângulo das chapas do estator em 10º, com o intuito de minimizar o efeito de correntes parasitas, sendo esse um dos fatores que influenciam os resultados. Para avaliação de desempenho, foi utilizada uma bancada de testes composta de analisador de energia, sensor de torque e instrumentos de medição, sendo o acionamento do protótipo realizado através de um motor de indução controlado por um inversor de frequência. Entre os resultados encontrados, foi constatada a presença de harmônicas que impactam sobre os valores obtidos do protótipo. Os testes realizados, de simulação e parâmetros elétricos, indicaram resultados apropriados ao desempenho de uma máquina elétrica trifásica, porém mostram-se necessárias alterações para um melhor desempenho do protótipo. / Development of a three-phase synchronous machine with Nd-Fe-B magnets and rotor core from sintered iron for application in 7.5 kW wind turbines, verifying the feasibility of the prototype. Starting from a previously developed design, a change in the angle of the stator plates was made in 10º, in order to minimize the effect of the parasite currents, being one of the factors that influence the results. For performance evaluation, a test bench composed of energy analyzer, torque sensor and measuring instruments was used, and the drive of the prototype was carried out through an induction motor controlled by a frequency inverter. Among the results found, it was verified the presence of harmonics that impact on the values obtained from the prototype. The tests performed, simulation and electrical parameters, indicated results appropriate to the performance of a three-phase electric machine, however changes are needed for a better performance of the prototype.

Desenvolvimento de uma máquina síncrona trifásica com ímãs de Nd-Fe-B e núcleo do rotor a partir de ferro sinterizado para aplicação em aerogeradores de 7,5 kW, verificando a viabilidade do protótipo. Partindo de um projeto anteriormente desenvolvido, foi realizada alteração no ângulo das chapas do estator em 10º, com o intuito de minimizar o efeito de correntes parasitas, sendo esse um dos fatores que influenciam os resultados. Para avaliação de desempenho, foi utilizada uma bancada de testes composta de analisador de energia, sensor de torque e instrumentos de medição, sendo o acionamento do protótipo realizado através de um motor de indução controlado por um inversor de frequência. Entre os resultados encontrados, foi constatada a presença de harmônicas que impactam sobre os valores obtidos do protótipo. Os testes realizados, de simulação e parâmetros elétricos, indicaram resultados apropriados ao desempenho de uma máquina elétrica trifásica, porém mostram-se necessárias alterações para um melhor desempenho do protótipo. / Development of a three-phase synchronous machine with Nd-Fe-B magnets and rotor core from sintered iron for application in 7.5 kW wind turbines, verifying the feasibility of the prototype. Starting from a previously developed design, a change in the angle of the stator plates was made in 10º, in order to minimize the effect of the parasite currents, being one of the factors that influence the results. For performance evaluation, a test bench composed of energy analyzer, torque sensor and measuring instruments was used, and the drive of the prototype was carried out through an induction motor controlled by a frequency inverter. Among the results found, it was verified the presence of harmonics that impact on the values obtained from the prototype. The tests performed, simulation and electrical parameters, indicated results appropriate to the performance of a three-phase electric machine, however changes are needed for a better performance of the prototype.

Radio frequency (RF) receivers are inherently non-linear due to non-linear components contained within the RF front-end such as the low noise amplifier (LNA) and mixer. When receivers operate in the non-linear region, this will affect the system performance due to intermodulation products, and cross-modulation, to name a few. Intermodulation products are the result of adjacent channel signals that combine and create intermodulation distortion of the received signal. We call these adjacent channel signals blockers. Receiving blockers are unavoidable in wideband receivers and their effect must be analyzed and properly addressed. This M.S. Thesis studies the effect of blockers on system performance, specifically the symbol error rate (SER), as a function of the receiver non-linearity figure and the blocking signal power and modulation format. There have been numerous studies on the effect of non-linearity in the probability of true and false detections in spectrum sensing when blockers are present. There has also been research showing the optimal modulation scheme for effective jamming. However, we are not aware of work analyzing the effect of modulated adjacent channel blockers on communication system performance. The approach taken in this paper is a theoretical derivation followed by numerical analysis aimed to quantify the effect of receiver nonlinearity on communication system performance as a function of (1) receiver characteristics, (2) blocking signal powers, (3) signal and blocker modulation format, and (4) phase-synchronized/non-synchronized blocker reception. The work focuses on M-PSK modulation schemes. For high blocker powers and non-linearity, the Es/No (Eb/No) performance loss can be as high as 4.7 dB for BPSK modulated signal and BPSK modulated blockers when received in sync with the desired signal. When blockers have a random phase offset with respect to the desired signal, the performance degradation is about 2 dB for BPSK modulated desired and blocker signals. It was found that for an BPSK transmitted signal with phase-synchronous blockers, the SER (BER) deteriorates the most when the blocking signals are of the same modulation. The effect is reduced, but still significant, as the modulation order of the signal of interest or the blockers, or both increases. / Master of Science / This thesis analyzes the effect of non-linear components in wireless receivers on communication system performance. We consider that two strong radio frequency signals adjacent in frequency to the desired signal enter the receiver and cause signal distortion known as 3rd order intermodulation distortion. We analyze the effect on the symbol error rate (SER) in the presence of two modulated blockers. SER defines the ratio of erroneously detected symbols to the total number of transmitted symbols and is a function of the modulation scheme and radio channel conditions. The SER analysis is done for Phase Shift Keying (PSK) modulated signals and blockers for different receiver types and blocker power levels. This thesis derives the theoretical SER expressions followed by numerical analysis aimed to quantify the effect of receiver non-linearity on communication system performance as a function of (1) receiver characteristics, (2) blocking signal powers, (3) signal and blocker modulation formats, and (4) phase-synchronized/non-synchronized reception of blockers. We justify the need for these new SER expressions and verify them via simulations. The thesis shows that modulated blockers can significantly impact communication system performance if the blockers are strong with respect to the signal of interest and if the device is highly non-linear. The work also shows that the performance degradation is a function of the blocker signal characteristics, but there are ways to overcome this loss by design or management. This has important implications on the management of spectrum in the new shared spectrum bands, where heterogeneous systems and devices will coexist with strong signals coming from nearby transmitters, radars or TV stations, among others.

The number of flights have increased by 80% between 1990 and 2014, and the demand for air travel continues to increase. Even though the aviation sector contributes to economical and social benefits, it still affects the climate change [1]. A first step to minimize the environmental impact is to develop more electric aircraft (MEA), where the idea is to maximize the use of electricity and improve the overall energy effciency [2]. In most of today's aircraft, large mechanical transmission shafts with a lot of components are driven by central power units, termed centralized drive systems. By the use of electromechanical actuators (EMAs), a distributed drive systems can be used instead, which increases functionality, reduces mass, maintenance and energy consumption, as well as improves manufacturing and assembly [3].  When designing electromechanical actuators, one must take into account a lot of parameters that affect each other in various ways. It is often a time-consuming job to find the most optimal choice of architecture. Parameters such as temperature, load, lifetime and effciency to mention a few. This master thesis offers a new analytical tool for EMAs of primary and secondary flight control systems for Saab Avionics Systems. The aim of the analytical tool is to characterize the parts of the system and identify important parameters in order to find the most optimal choice of architecture. The tool focus on the main mechanical components such as the three-phase synchronous permanent magnet motor, power-off brake, two-stage planetary gearbox and ball screw. The tool developed in this project generates an initial design of the EMA with optimized dimensions in order to minimize both mass and energy consumption. It functions by identifying three main groups of parameters: The input parameters: fixed values defined by the customer demands The design parameters: variables that the user can change to find the optimal choice of architecture The output parameters: resulting values of either performance or dimensions By defining few design parameters for each component, and implementing multidisciplinary design optimization (MDO), the analytical tool can find an optimized solution for each specific project in a time-efficient way. The final values of the parameters characterize the performance of the EMA.