published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

Testing integrated circuits to verify their operating frequency, known as delay testing, is essential to achieve acceptable product quality. The high cost of functional testing has driven the industry to automatically-generated structural tests, applied by low-cost testers taking advantage of design-for-test (DFT) circuitry on the chip. Traditional at-speed functional testing of digital circuits is increasingly challenged by new defect types and the high cost of functional test development. This research addressed the problems of accurate delay testing in DSM circuits by targeting resistive open and short circuits, while taking into account manufacturing process variation, power dissipation and power supply noise. In this work, we developed a class of structural delay tests in which we extended traditional launch-on-capture delay testing to additional launch and capture cycles. We call these Pseudofunctional Tests (PFT). A test pattern is scanned into the circuit, and then multiple functional clock cycles are applied to it with at-speed launch and capture for the last two cycles. The circuit switching activity over an extended period allows the off-chip power supply noise transient to die down prior to the at-speed launch and capture, achieving better timing correlation with the functional mode of operation. In addition, we also proposed advanced compaction methodologies to compact the generated test patterns into a smaller test set in order to reduce the test application time. We modified our CodGen K longest paths per gate automatic test pattern generator to implement PFT pattern generation. Experimental results show that PFT test generation is practical in terms of test generation time.

Intrinsically safe (IS) active power supplies subjected to certain transient load conditions can deliver power to a circuit at significantly higher levels than indicated on their nameplate ratings. During a transient load such as an intermittent short-circuit, energy is transferred from the power supply to the short-circuit and an electrical arc may form when the short-circuit is applied or removed. This poses a spark ignition risk as energy is transferred from the arc to the surrounding atmosphere. Currently various International and Australian Standards define the performance requirements for IS electrical apparatus. A duly accredited laboratory is required to establish the intrinsic safety compliance of an apparatus with the Standards. It involves an assessment of the apparatus and may include testing. The assessment of the apparatus determines adequate segregation, separation, construction, and selection of components. The tests performed on the apparatus include a temperature rise test and in some cases, the sparking potential of the circuit is tested using the spark test apparatus (STA). Testing the sparking potential of active power supplies to establish compliance adds significantly to the time and costs involved in establishing compliance. A new alternative assessment method is proposed in this report to augment or replace the testing phase of the compliance certification process for active power supplies. The proposed alternative assessment method (PAAM) is derived from a determination of the steady-state and transient output characteristics of the active power supply under consideration. Parameters such as peak output current, time constant of peak current decay, and the output voltages at these times are measured from the circuit's output characteristics. These measurements can subsequently be used to derive the topology and component values of an equivalent circuit. The resulting equivalent circuit is then considered like a linear power supply and the sparking potential can be determined using existing assessment methods. This thesis investigates in detail the equivalent circuit of a number of direct current (DC) active power supplies whose transient output characteristics exhibit predominantly capacitive behaviour. The results of the PAAM using the equivalent circuit are then compared with results achieved using the current testing procedure with a STA. A small sample of active power supplies is used to generate data from which a relationship between the current testing procedure and the PAAM can be established. The PAAM developed in this research project can be used as a pre-compliance check by designers, manufacturers, or IS testing stations. A failure of this test would indicate that the active power supply's sparking energy is not low enough to be regarded as intrinsically safe. The PAAM requires fewer resources to establish a result than the STA. The benefits of a simplified spark ignition test would flow on from designers and manufacturers to end users.

Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2007. / La p. de t. porte en outre: Mémoire présenté comme exigence partielle de la maîtrise en ingénierie. CaQCU Bibliogr.: f. [121]-124. Document électronique également accessible en format PDF. CaQCU

In the current and next generation automotive telematic platforms, high demands are put on high efficiency power supplies. This thesis investigates different switch mode power converter solutions that operates with high efficiency for both low and high power loads. A market survey was conducted alongside meetings with ACTIA Nordic and their subcontractors. Three solutions from the market survey were selected for further investigation. One solution from the investigation was selected and implemented as a demonstration platform for further testing. The result shows a full test sequence for the designed power supply solution.

Sjukhus och flygplatser är precis som resten av samhället, beroende av el. Med dagens teknik är sjukhus och flygplatser högteknologiska ochväldigt störningskänsliga för elbortfall,vilket gör det viktigt att ha en stabil och säker kraftförsörjning utan avbrott. Ett avbrott i strömförsörjningen kan orsaka allvarliga,till och med livsfarliga konsekvenser. Att säkerställa ett bra och redundant reservkraftsystemär väsentligt för sjukhusen och flygplatserna. Syftet med studien var att undersöka samt ta fram reservkraftsystem med redundansförsjukhus och flygplatser. Under arbetets gång har litteraturstudie om generatorer och UPS-system (uninterruptible power supply) gjorts samt intervjuer med experter inom båda ämnena. Resultat visar de fundamentala delarna som är viktiga att ta hänsyn till vid dimensionering av reservkraftsystem. Men det visar också på att det finns många faktorersom spelar in vid dimensionering av systemen, vilket leder till att alla system ser olika ut och det finns inte riktigtnågon specifik mall att följa. / Hospitals and airports are just like the rest of society, dependent onelectricity. With today's technology, hospitals and airports are highly technological and highly sensitiveto electricity loss. Thatmakes it important to have stable and secure power supply without interruptions. An interruption of power supply can cause serious even fatal consequences. Ensuring a good and redundant reserve power system is essential for hospitals and airports. The purpose of the study was to investigate and provide good redundant solutions for reserve systems in hospitals and airports. During the course of the thesis, literature studies ofgenerators and UPS (uninterruptible power supply) systems have been conducted as well as interviews with experts in both subjects.Results show the fundamental aspects that should be taken into account when dimensioning reserve power systems. But it also shows that there are many aspects that affectthe system dimensioning, which means that all systems look different and there is no specific template to follow.

CAPES / Este trabalho tem como objetivo a análise, projeto e implementação de estratégias de controle repetitivo para aplicação em sistemas de alimentação ininterrupta de energia (UPS - Uninterruptible Power Supply). Inicialmente, a revisão da literatura aborda os controladores mais aplicados neste propósito. Uma visão geral sobre sistemas UPS é realizada, com foco em diferentes topologias e o projeto de um filtro indutivo capacitivo (LC), para reduzir o conteúdo harmônico proveniente das comutações do inversor, é discutido. Na sequência, uma estratégia de controle é proposta. Nesta estratégia um termo feedforward é utilizado para gerar a forma de onda da tensão de saída e um controlador do tipo proporcional derivativo (PD) é inserido para compensar distúrbios não cíclicos. Para compensação de distúrbios cíclicos, algumas técnicas de controle repetitivo são analisadas e implementadas. A adição destes controladores apresenta bom desempenho, porém, quando o sistema sofre interferências, as características dinâmicas destes controladores são afetadas. Modificações são realizadas para tornar o sistema menos suscetível a ruídos de alta frequência e a distúrbios aperiódicos. Ainda, é proposto um controlador repetitivo com adaptação do ganho que apresenta robustez suficiente para boa regulação de tensão mesmo na presença de distúrbios aperiódicos e interferências eletromagnéticas. Por fim, é descrita a implementação de uma plataforma flexível, baseado em um inversor PWM controlado por um processador digital de sinais com periféricos para aquisição de dados e geração de PWM, DSC TMS320F28335. A partir desta plataforma, foram obtidos resultados experimentais para um protótipo de uma UPS monofásica, os quais comprovam o desempenho das técnicas de controle apresentadas e propostas. / This work presents an analysis, design and implementation of repetitive control strategies applied to uninterruptible power supplies (UPS) systems. At the beginning, a literature review of the main controllers concerning this purpose is shown. A global vision of UPS systems with focus on different topologies is made and the project of an inductive capacitive filter (LC) is presented where the goal is to reduce harmonic content due to the inverter switching. After that, a control strategy is presented. In this strategy a feed forward term is used to generate the wave form shape of the output voltage and a Proportional Derivative (PD) controller is introduced to compensate non cyclic disturbances. For the compensation of cyclic disturbs some repetitive control techniques are analyzed and implemented. The inclusion of these controllers provides a good performance for the output system, however, when the system is exposed to interferences, the dynamic characteristics of these controllers are affected. Modifications are presented to make the system less susceptible for high frequencies noise and aperiodic disturbs. In addition, a repetitive controller with gain adaptation is proposed with sufficient robustness to obtain a good voltage regulation even in the presence of aperiodic disturbances and electromagnetic interferences. Finally, the implementation of a flexible platform is presented, based on PWM inverter controlled by a digital signal processor with data acquisition and generation PWM peripherals, DSP TMS320F28335. From this platform, experimental results for a monophasic UPS prototype was obtained, which ones prove the performance of the control techniques presented and proposed.

CAPES / Este trabalho traz um estudo da aplicação do conversor Full-Bridge bidirecional como um carregador de banco de baterias em um barramento CC de fontes de energia renováveis. O problema principal destas fontes é que são sazonais e não oferecem uma continuidade de fornecimento de potência. Assim, o uso de banco de baterias, conectado a um barramento CC compartilhado com outras fontes renováveis traz contribuições na continuidade do fornecimento de energia. O conversor proposto neste trabalho visa conectar o banco de baterias ao barramento CC e ao mesmo tempo que faz a integração dos modos de carga e descarga em um único conversor. Adicionalmente, para reduzir volume, é utilizado um transformador planar que oferece alta eficiência (máximo de 99,5%) e uma reduzida relação volume/potência. O conversor foi desenvolvido para carregar um banco de baterias de 192V. No modo de descarga, ele é suado para alimentar um barramento CC de 400V com uma potência máxima de 1,34kW. Apesar do uso do conversor full-bridge não ser novidade nestes tipos de aplicação, dois fatores serviram de motivação para este trabalho: o uso do transformador planar e a tendência mundial de integração de fontes renováveis. / This work presents a study of the application of the Full-bridge bidirectional DC converter as a battery bank charger in a DC bus of renewable energy sources. The main problem is that these sources are seasonal and do not offer a continuously power supply. Thus, the use of a battery bank connected to a DC bus shared with other renewable sources brings contributions in the continuity of power supply. The converter proposed in this work aims to connect the battery bank to the DC bus at the same time it integrates the charging and discharging modes into a single converter. Additionally, to reduce the volume, it is used a planar transformer that provides high efficiency (up to 99.5%) and a reduced volume/power ratio. The converter is designed to charge a bank of batteries of 192V. At the discharge mode, it is designed to feed a 400V DC bus with maximum power of 1.34 kW. Despite the use of the full-bridge converter is not new in these types of application, two factors served as motivation for this work: the use of planar transformer and the global trend of integration of renewable sources.

CAPES / Este trabalho tem como objetivo a análise, projeto e implementação de estratégias de controle repetitivo para aplicação em sistemas de alimentação ininterrupta de energia (UPS - Uninterruptible Power Supply). Inicialmente, a revisão da literatura aborda os controladores mais aplicados neste propósito. Uma visão geral sobre sistemas UPS é realizada, com foco em diferentes topologias e o projeto de um filtro indutivo capacitivo (LC), para reduzir o conteúdo harmônico proveniente das comutações do inversor, é discutido. Na sequência, uma estratégia de controle é proposta. Nesta estratégia um termo feedforward é utilizado para gerar a forma de onda da tensão de saída e um controlador do tipo proporcional derivativo (PD) é inserido para compensar distúrbios não cíclicos. Para compensação de distúrbios cíclicos, algumas técnicas de controle repetitivo são analisadas e implementadas. A adição destes controladores apresenta bom desempenho, porém, quando o sistema sofre interferências, as características dinâmicas destes controladores são afetadas. Modificações são realizadas para tornar o sistema menos suscetível a ruídos de alta frequência e a distúrbios aperiódicos. Ainda, é proposto um controlador repetitivo com adaptação do ganho que apresenta robustez suficiente para boa regulação de tensão mesmo na presença de distúrbios aperiódicos e interferências eletromagnéticas. Por fim, é descrita a implementação de uma plataforma flexível, baseado em um inversor PWM controlado por um processador digital de sinais com periféricos para aquisição de dados e geração de PWM, DSC TMS320F28335. A partir desta plataforma, foram obtidos resultados experimentais para um protótipo de uma UPS monofásica, os quais comprovam o desempenho das técnicas de controle apresentadas e propostas. / This work presents an analysis, design and implementation of repetitive control strategies applied to uninterruptible power supplies (UPS) systems. At the beginning, a literature review of the main controllers concerning this purpose is shown. A global vision of UPS systems with focus on different topologies is made and the project of an inductive capacitive filter (LC) is presented where the goal is to reduce harmonic content due to the inverter switching. After that, a control strategy is presented. In this strategy a feed forward term is used to generate the wave form shape of the output voltage and a Proportional Derivative (PD) controller is introduced to compensate non cyclic disturbances. For the compensation of cyclic disturbs some repetitive control techniques are analyzed and implemented. The inclusion of these controllers provides a good performance for the output system, however, when the system is exposed to interferences, the dynamic characteristics of these controllers are affected. Modifications are presented to make the system less susceptible for high frequencies noise and aperiodic disturbs. In addition, a repetitive controller with gain adaptation is proposed with sufficient robustness to obtain a good voltage regulation even in the presence of aperiodic disturbances and electromagnetic interferences. Finally, the implementation of a flexible platform is presented, based on PWM inverter controlled by a digital signal processor with data acquisition and generation PWM peripherals, DSP TMS320F28335. From this platform, experimental results for a monophasic UPS prototype was obtained, which ones prove the performance of the control techniques presented and proposed.

CAPES / Este trabalho traz um estudo da aplicação do conversor Full-Bridge bidirecional como um carregador de banco de baterias em um barramento CC de fontes de energia renováveis. O problema principal destas fontes é que são sazonais e não oferecem uma continuidade de fornecimento de potência. Assim, o uso de banco de baterias, conectado a um barramento CC compartilhado com outras fontes renováveis traz contribuições na continuidade do fornecimento de energia. O conversor proposto neste trabalho visa conectar o banco de baterias ao barramento CC e ao mesmo tempo que faz a integração dos modos de carga e descarga em um único conversor. Adicionalmente, para reduzir volume, é utilizado um transformador planar que oferece alta eficiência (máximo de 99,5%) e uma reduzida relação volume/potência. O conversor foi desenvolvido para carregar um banco de baterias de 192V. No modo de descarga, ele é suado para alimentar um barramento CC de 400V com uma potência máxima de 1,34kW. Apesar do uso do conversor full-bridge não ser novidade nestes tipos de aplicação, dois fatores serviram de motivação para este trabalho: o uso do transformador planar e a tendência mundial de integração de fontes renováveis. / This work presents a study of the application of the Full-bridge bidirectional DC converter as a battery bank charger in a DC bus of renewable energy sources. The main problem is that these sources are seasonal and do not offer a continuously power supply. Thus, the use of a battery bank connected to a DC bus shared with other renewable sources brings contributions in the continuity of power supply. The converter proposed in this work aims to connect the battery bank to the DC bus at the same time it integrates the charging and discharging modes into a single converter. Additionally, to reduce the volume, it is used a planar transformer that provides high efficiency (up to 99.5%) and a reduced volume/power ratio. The converter is designed to charge a bank of batteries of 192V. At the discharge mode, it is designed to feed a 400V DC bus with maximum power of 1.34 kW. Despite the use of the full-bridge converter is not new in these types of application, two factors served as motivation for this work: the use of planar transformer and the global trend of integration of renewable sources.