This diploma thesis is focused on synthetic loads, especially electronically controlled loads. The thesis analyse principles of mechanically and electronically controlled loads and theirs operation modes. The paper also carried out a search of AC loads available on the market. The parameters of the AC load were based on the requirements provided by client. The functionality of the designed load is verified by simulation. The thesis continues with realization of the designed schematics and bringing the load to function. At the last section of the thesis are detail parameters of the designed load verified by measurement.

In hydropower plants, a local load, also known as a dump load, could be installed to balance theelectrical grid by consuming excessive power. This enhances the dam safety. A design for asmall-scaled three-phase dump load is presented in this thesis. The designed model is built andevaluated through simulations and experiments. The results show that the system is purelyresistive. The per phase resistance of the model can be calculated with geometrical analysis ofthe design.

Master of Science / Department of Electrical and Computer Engineering / Dwight D. Day / Micro-hydro turbines generate power for small villages and industries in Afghanistan. They usually produce less than 100 kW of power. Currently the flow into the turbine is controlled manually and the voltage is controlled automatically with an electronic load controller. Excess power not used by the village is dumped into a community water heater. For larger sites that have a reservoir and/or large variable load throughout the day and night, the turbine needs to be fitted with an automatic flow control system to conserve water in the reservoir or deal with the variable loads. Large turbines usually use hydraulic governors that automatically adjust the flow of water into the turbine. For micro-hydro sized plants this method would be too expensive and be difficult to build and maintain locally. For this reason, a 3 phase AC induction motor will be used to move the internal flow control valve of the turbine. Because a sudden change in load is possible (30 – 40%) for micro-hydro plants, the electronic load controller will also be needed to respond to quick changes in load so that the village voltage does not exceed 220V. This report documents the process of building a test system comprising of a dynamic resistive load, microcontroller controlled resistive load, a three phase AC generator and a DC Motor. Where the dynamic resistive load represents the load of the village, the computer controlled resistive load would represent the community water heater, the three phase AC generator represents the Generator on site and the DC Motor together with its DC input voltage would emulate the turbine and its water flow respectively. The DC input voltage would be also controlled with a PWM signal through a delay loop to represent the water gate delay effects on the turbine as close as possible. With this, it would be possible to completely build and test a control system that emulates the dynamics of a water turbine generator.

Objetivos: Avaliar a percepção da dispneia em pacientes com fibrose cística (FC) comparando com indivíduos normais, durante teste com cargas resistivas inspiratórias e durante teste de caminhada de seis minutos (TC6M). Secundariamente, avaliar a correlação entre os escores de dispneia induzida pelas cargas resistivas e os escores de dispneia provocada pelo TC6M. Métodos: estudo transversal em pacientes com FC (≥15 anos) e indivíduos normais. Os voluntários foram submetidos a teste com cargas resistivas inspiratórias, medida das pressões respiratórias máximas, espirometria, avaliação nutricional e TC6M. Resultados: Foram incluídos no estudo 31 pacientes com FC pareados com 31 indivíduos normais. À medida que a magnitude das cargas resistivas inspiratórias aumentou, os escores de dispneia aumentaram (p<0,001), porém não houve diferença entre grupos quanto ao escore de dispneia (p=0,654) e não houve efeito de interação (p=0,654). SpO2 foi menor em pacientes com FC (p<0,001) e aumentou à medida que a magnitude das cargas aumentou (p<0,001), sem ocorrer efeito de interação (p=,364). Vinte e seis (84%) indivíduos normais completaram o teste com cargas resistivas, comparado com apenas 12 (39%) dos pacientes com FC (p<0,001). Os escores de dispneia foram maiores ao final do TC6M do que no repouso (p<0,001), mas não houve diferença entre os grupos (p=0,080) e não houve efeito de interação (p=0,091). SpO2 foi menor nos pacientes com FC (p<0,001) e diminuiu do repouso ao final do TC6M nos pacientes com FC (p<0,001) com efeito de interação (p=0,004). Os escores de dispneia ao final do TC6M correlacionaram-se significativamente com os escores de dispneia induzidos pelo teste com cargas resistivas. Conclusão: a percepção da dispneia em pacientes com FC induzidos por teste com cargas resistivas inspiratórias e pelo TC6M não diferiu dos indivíduos normais. Contudo, os pacientes com FC descontinuaram o teste com cargas resistivas inspiratórias mais frequentemente. Além disso, houve correlação significativa entre o escore de percepção da dispneia induzida pelas cargas resistivas inspiratórias e pelo TC6M. / Objectives: To evaluate dyspnea perception in cystic fibrosis (CF) patients compared with normal subjects, during inspiratory resistive loading and the six-minute walk test (6MWT). Secondarily, to assess the correlation between dyspnea scores induced by resistive loads and those induced by the 6MWT. Methods: cross-sectional study in patients with CF (≥15 years old) and normal subjects. Volunteers underwent inspiratory resistive loading, measurement of maximal respiratory pressures, spirometry, nutritional evaluation, and the 6MWT. Results: Thirty-one CF patients and 31 paired normal subjects were included in the study. As the magnitude of the inspiratory loads increased, dyspnea scores increased (p<.001), but there was no difference between groups in dyspnea score (p=.654) and no group interaction effect (p=.654). SpO2 was lower in CF patients (p<.001) and increased as the magnitude of the loads increased (p<.001), with no interaction effect (p=.364). Twenty-six (84%) normal subjects completed the whole test, compared to only 12 (39%) CF patients (p<.001). Dyspnea scores were higher post-6MWT than at rest (p<.001), but did not differ between groups (p=.080) with no interaction effect (p=.091). SpO2 was lower in CF patients (p<.001) and decreased from resting to post-6MWT in CF patients (p<.001) with an interaction effect (p=.004). Post-6MWT dyspnea scores were significantly correlated with dyspnea scores induced by resistive loads. Conclusion: dyspnea perception in CF patients induced by inspiratory resistive loading and by 6MWT did not differ from normal subjects. However, CF patients discontinued inspiratory resistive loading more frequently. In addition, there were significant correlations between dyspnea perception score induced by inspiratory resistance loading and by the 6MWT.

Objetivos: Avaliar a percepção da dispneia em pacientes com fibrose cística (FC) comparando com indivíduos normais, durante teste com cargas resistivas inspiratórias e durante teste de caminhada de seis minutos (TC6M). Secundariamente, avaliar a correlação entre os escores de dispneia induzida pelas cargas resistivas e os escores de dispneia provocada pelo TC6M. Métodos: estudo transversal em pacientes com FC (≥15 anos) e indivíduos normais. Os voluntários foram submetidos a teste com cargas resistivas inspiratórias, medida das pressões respiratórias máximas, espirometria, avaliação nutricional e TC6M. Resultados: Foram incluídos no estudo 31 pacientes com FC pareados com 31 indivíduos normais. À medida que a magnitude das cargas resistivas inspiratórias aumentou, os escores de dispneia aumentaram (p<0,001), porém não houve diferença entre grupos quanto ao escore de dispneia (p=0,654) e não houve efeito de interação (p=0,654). SpO2 foi menor em pacientes com FC (p<0,001) e aumentou à medida que a magnitude das cargas aumentou (p<0,001), sem ocorrer efeito de interação (p=,364). Vinte e seis (84%) indivíduos normais completaram o teste com cargas resistivas, comparado com apenas 12 (39%) dos pacientes com FC (p<0,001). Os escores de dispneia foram maiores ao final do TC6M do que no repouso (p<0,001), mas não houve diferença entre os grupos (p=0,080) e não houve efeito de interação (p=0,091). SpO2 foi menor nos pacientes com FC (p<0,001) e diminuiu do repouso ao final do TC6M nos pacientes com FC (p<0,001) com efeito de interação (p=0,004). Os escores de dispneia ao final do TC6M correlacionaram-se significativamente com os escores de dispneia induzidos pelo teste com cargas resistivas. Conclusão: a percepção da dispneia em pacientes com FC induzidos por teste com cargas resistivas inspiratórias e pelo TC6M não diferiu dos indivíduos normais. Contudo, os pacientes com FC descontinuaram o teste com cargas resistivas inspiratórias mais frequentemente. Além disso, houve correlação significativa entre o escore de percepção da dispneia induzida pelas cargas resistivas inspiratórias e pelo TC6M. / Objectives: To evaluate dyspnea perception in cystic fibrosis (CF) patients compared with normal subjects, during inspiratory resistive loading and the six-minute walk test (6MWT). Secondarily, to assess the correlation between dyspnea scores induced by resistive loads and those induced by the 6MWT. Methods: cross-sectional study in patients with CF (≥15 years old) and normal subjects. Volunteers underwent inspiratory resistive loading, measurement of maximal respiratory pressures, spirometry, nutritional evaluation, and the 6MWT. Results: Thirty-one CF patients and 31 paired normal subjects were included in the study. As the magnitude of the inspiratory loads increased, dyspnea scores increased (p<.001), but there was no difference between groups in dyspnea score (p=.654) and no group interaction effect (p=.654). SpO2 was lower in CF patients (p<.001) and increased as the magnitude of the loads increased (p<.001), with no interaction effect (p=.364). Twenty-six (84%) normal subjects completed the whole test, compared to only 12 (39%) CF patients (p<.001). Dyspnea scores were higher post-6MWT than at rest (p<.001), but did not differ between groups (p=.080) with no interaction effect (p=.091). SpO2 was lower in CF patients (p<.001) and decreased from resting to post-6MWT in CF patients (p<.001) with an interaction effect (p=.004). Post-6MWT dyspnea scores were significantly correlated with dyspnea scores induced by resistive loads. Conclusion: dyspnea perception in CF patients induced by inspiratory resistive loading and by 6MWT did not differ from normal subjects. However, CF patients discontinued inspiratory resistive loading more frequently. In addition, there were significant correlations between dyspnea perception score induced by inspiratory resistance loading and by the 6MWT.

Objetivos: Avaliar a percepção da dispneia em pacientes com fibrose cística (FC) comparando com indivíduos normais, durante teste com cargas resistivas inspiratórias e durante teste de caminhada de seis minutos (TC6M). Secundariamente, avaliar a correlação entre os escores de dispneia induzida pelas cargas resistivas e os escores de dispneia provocada pelo TC6M. Métodos: estudo transversal em pacientes com FC (≥15 anos) e indivíduos normais. Os voluntários foram submetidos a teste com cargas resistivas inspiratórias, medida das pressões respiratórias máximas, espirometria, avaliação nutricional e TC6M. Resultados: Foram incluídos no estudo 31 pacientes com FC pareados com 31 indivíduos normais. À medida que a magnitude das cargas resistivas inspiratórias aumentou, os escores de dispneia aumentaram (p<0,001), porém não houve diferença entre grupos quanto ao escore de dispneia (p=0,654) e não houve efeito de interação (p=0,654). SpO2 foi menor em pacientes com FC (p<0,001) e aumentou à medida que a magnitude das cargas aumentou (p<0,001), sem ocorrer efeito de interação (p=,364). Vinte e seis (84%) indivíduos normais completaram o teste com cargas resistivas, comparado com apenas 12 (39%) dos pacientes com FC (p<0,001). Os escores de dispneia foram maiores ao final do TC6M do que no repouso (p<0,001), mas não houve diferença entre os grupos (p=0,080) e não houve efeito de interação (p=0,091). SpO2 foi menor nos pacientes com FC (p<0,001) e diminuiu do repouso ao final do TC6M nos pacientes com FC (p<0,001) com efeito de interação (p=0,004). Os escores de dispneia ao final do TC6M correlacionaram-se significativamente com os escores de dispneia induzidos pelo teste com cargas resistivas. Conclusão: a percepção da dispneia em pacientes com FC induzidos por teste com cargas resistivas inspiratórias e pelo TC6M não diferiu dos indivíduos normais. Contudo, os pacientes com FC descontinuaram o teste com cargas resistivas inspiratórias mais frequentemente. Além disso, houve correlação significativa entre o escore de percepção da dispneia induzida pelas cargas resistivas inspiratórias e pelo TC6M. / Objectives: To evaluate dyspnea perception in cystic fibrosis (CF) patients compared with normal subjects, during inspiratory resistive loading and the six-minute walk test (6MWT). Secondarily, to assess the correlation between dyspnea scores induced by resistive loads and those induced by the 6MWT. Methods: cross-sectional study in patients with CF (≥15 years old) and normal subjects. Volunteers underwent inspiratory resistive loading, measurement of maximal respiratory pressures, spirometry, nutritional evaluation, and the 6MWT. Results: Thirty-one CF patients and 31 paired normal subjects were included in the study. As the magnitude of the inspiratory loads increased, dyspnea scores increased (p<.001), but there was no difference between groups in dyspnea score (p=.654) and no group interaction effect (p=.654). SpO2 was lower in CF patients (p<.001) and increased as the magnitude of the loads increased (p<.001), with no interaction effect (p=.364). Twenty-six (84%) normal subjects completed the whole test, compared to only 12 (39%) CF patients (p<.001). Dyspnea scores were higher post-6MWT than at rest (p<.001), but did not differ between groups (p=.080) with no interaction effect (p=.091). SpO2 was lower in CF patients (p<.001) and decreased from resting to post-6MWT in CF patients (p<.001) with an interaction effect (p=.004). Post-6MWT dyspnea scores were significantly correlated with dyspnea scores induced by resistive loads. Conclusion: dyspnea perception in CF patients induced by inspiratory resistive loading and by 6MWT did not differ from normal subjects. However, CF patients discontinued inspiratory resistive loading more frequently. In addition, there were significant correlations between dyspnea perception score induced by inspiratory resistance loading and by the 6MWT.