ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / This paper presents a practical implementation of a hardware design for transmission of data over aircraft power lines. The intent of such hardware is to significantly reduce the wiring in the aircraft instrumentation system. The potential usages of this technology include pulse code modulation (PCM), Ethernet and other forms data communications. Details of the fieldprogrammable gate array (FPGA) and printed circuit board (PCB) designs of the digital and analog front end will be discussed. The power line is not designed for data transmission. It contains considerable noise, multipath effects, and time varying impedance. Spectral analysis data of an aircraft is presented to indicate the difficulty of the problem at hand. A robust modulation is required to overcome the harsh environment and to provide reliable transmission. Orthogonal frequency division multiplexing (OFDM) has been used in power line communication industry with a great deal of success. OFDM has been deemed the most appropriate technology for high-speed data transmission on aircraft power lines. Additionally, forward error correction (FEC) techniques are discussed.

O presente trabalho tem como objetivo propor uma metodologia para avaliar o impacto das diversas técnicas de repotenciação no desempenho de linhas de transmissão em regime permanente, visto que na atual literatura não existe uma análise abrangente que possa ser aplicada em qualquer linha de transmissão carente de repotenciação. A metodologia busca fornecer subsídios para escolha da técnica mais vantajosa para repotenciar uma linha, utilizando de forma extensiva, os fatores de desempenho, e de forma sintetizada, os índices de mérito agregado, que, avaliados individualmente e/ou em conjunto, propiciam informações qualificadas para as conclusões técnicas. Destaca-se que a proposição dos fatores de desempenho e dos índices de mérito são as principais contribuições deste trabalho. Para complementar a metodologia, uma análise de curtos-circuitos foi proposta. Os resultados da utilização da metodologia foram positivos, possibilitando verificar os ganhos de potência na transmissão de energia. Vale destacar a eficiência dos índices de mérito agregado, que identificaram a melhor técnica de repotenciação de forma sintetizada, resguardando a qualidade e enquadramento dos resultados nas normas regulamentadoras. / This work aims at proposing a methodology to assessing the impact of power upgrade techniques on the steady-state performance of transmission lines, since there is not anything similar to this in the technical literature. The proposed methodology aims at providing technical information to subside the choice of the best power line upgrade technique, by the extensive application of the performance factors and of the aggregate merit indices. It must be pointed out that the proposition of the performance factors and of the aggregate merit indices are the main contributions of this work. Additionally, a short circuit analysis was also proposed to assess the power upgrade techniques. The results after the method application were satisfactory and allowed verifying the surplus of power related to each upgrade technique. The contribution of the aggregate merit indices was very important to identifying the most favorable upgrade technique in a simple way, so that all statutory technical limits were not violated.

O presente trabalho tem como objetivo propor uma metodologia para avaliar o impacto das diversas técnicas de repotenciação no desempenho de linhas de transmissão em regime permanente, visto que na atual literatura não existe uma análise abrangente que possa ser aplicada em qualquer linha de transmissão carente de repotenciação. A metodologia busca fornecer subsídios para escolha da técnica mais vantajosa para repotenciar uma linha, utilizando de forma extensiva, os fatores de desempenho, e de forma sintetizada, os índices de mérito agregado, que, avaliados individualmente e/ou em conjunto, propiciam informações qualificadas para as conclusões técnicas. Destaca-se que a proposição dos fatores de desempenho e dos índices de mérito são as principais contribuições deste trabalho. Para complementar a metodologia, uma análise de curtos-circuitos foi proposta. Os resultados da utilização da metodologia foram positivos, possibilitando verificar os ganhos de potência na transmissão de energia. Vale destacar a eficiência dos índices de mérito agregado, que identificaram a melhor técnica de repotenciação de forma sintetizada, resguardando a qualidade e enquadramento dos resultados nas normas regulamentadoras. / This work aims at proposing a methodology to assessing the impact of power upgrade techniques on the steady-state performance of transmission lines, since there is not anything similar to this in the technical literature. The proposed methodology aims at providing technical information to subside the choice of the best power line upgrade technique, by the extensive application of the performance factors and of the aggregate merit indices. It must be pointed out that the proposition of the performance factors and of the aggregate merit indices are the main contributions of this work. Additionally, a short circuit analysis was also proposed to assess the power upgrade techniques. The results after the method application were satisfactory and allowed verifying the surplus of power related to each upgrade technique. The contribution of the aggregate merit indices was very important to identifying the most favorable upgrade technique in a simple way, so that all statutory technical limits were not violated.

Wearable systems continue to gain new markets by addressing improved performance and lower size, weight and cost. Both civilian and military markets have incorporated wearable technologies to enhance and facilitate user's tasks and activities. A wearable system is a heterogeneous system composed of diverse electronic modules: data processing, input and output modules. The system is constructed to be body-borne and therefore, several constraints are put on wearable systems regarding wearability (size, weight, placement, etc.) and robustness rendering the task of designing wearable systems challenging. In this thesis, an overview of wearable systems was given by discussing definition, technology challenges, market analysis and design methodologies. Main research targeted at network architectures and robustness to environmental stresses and electromagnetic interference (EMI). The network architecture designated the data communication on the intermodule level - topology and infrastructure. A deeper analysis of wearable requirements on the network architecture was made and a new architecture is proposed based on DC power line communication network (DC-PLC). In addition, wired data communication was compared to wireless data communication by introducing statistical communication model and looking at multiple design attributes: power efficiency, scalability, and wearability. The included papers focused on wearable systems related issues including analysis of present situation, environmental and electrical robustness studies, theoretical and computer aided modelling, and experimental testing to demonstrate new wearable architectural concepts. A roadmap was given by examining the past and predicting the future of wearable systems in terms of technology, market, and architecture. However, the roadmap was updated within this thesis to include new market growth figures that proved to be far less than was predicted in 2004. User and application environmental requirements to be applied on future wearable systems were identified. A procedure is presented to address EMI and evaluated solutions in wearable application through modelling and simulation. Environmental robustness and wearability of wearable systems in general, and washability and conductive textile in particular are investigated. A measurement-based methodology to model electrical properties of conductive textile when subjected to washing was given. Employing a wired data communication network was found to be more appropriate for wearable systems than wireless networks when prioritizing power efficiency. The wearability and scalability of the wired networks was enhanced through conductive textile and DC-PLC, respectively. A basic wearable application was built to demonstrate the suitability of DC-PLC communication with conductive textile as infrastructure. The conductive textile based on metal filament showed better mechanical robustness than metal plated conductive textile. A more advanced wearable demonstrator, where DC-PLC network was implemented using transceivers, further strengthened the proposed wearable architecture. Based on the overview, the theoretical, modelling and experimental work, a possible approach of designing wearable systems that met several contradicting requirements was given.

This dissertation describes the role played by bird streamers in transmission line faults under HVDC conditions. The research was initiated due to the lack of knowledge of these faults under HVDC conditions. An explanation as to what bird streamers faults are, the role they play in the breakdown of air-gaps and a means of preventing bird streamer caused faults from occurring is made Experimental work has been carried out in order to gain an understanding of these faults under HVDC conditions. The overall aim of the experiments was to find a horizontal distance (protected zone) on an HVDC tower top, in order to prevent birds from perching around the centre of the tower. This will lead to a reduction of bird streamer caused faults. A brass rod was used as the artificial streamer in the experiments, under both negative and positive polarity (voltages in the range 0 to 220 kV DC were applied). Later in the experimental phase, a string soaked in a saline solution was used as a more realistic simulation of a bird streamer. QuickField™, an FEM package, was used to simulate the electric field in the region of the live conductor fitting and the tip of the bird streamer, to assess the degree of distortion of the electric field caused by the introduction of the bird streamer. These simulations served as means of verifying the laboratory experiments. This dissertation has proposed a relationship between the breakdown voltage and the protected zone length, based on the air-gap breakdown voltages for both I-String and V-String insulator configurations in the air-gap range 0 to 350 mm. These curves can be used in the design of transmission lines, as a means of reducing bird streamer faults. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2007.

Hydraulic manipulators commonly interact with environments that are highly unstructured, and thus rely on the intelligence of human operators to provide proper commands. Typically, operators use visual information, directly or through cameras, to perform a task. Providing haptic or touch sensation about the task environment to the operator, enhances her/his ability to perform telemanipulation. The focus of this thesis is on haptic teleoperation of hydraulic manipulators. The application is directed at live transmission line maintenance tasks. In this thesis, both unilateral and bilateral haptic teleoperation of hydraulic manipulators are investigated. On the unilateral telemanipulation front, position error is shown to be an important issue in performing repetitive tasks. The most important sources of inaccuracy in position are sensors, robot controller performance, and the operator. To reduce the human operator’s errors, the concept of virtual fixtures is adopted in this research. It is shown that virtual fixtures can help operators perform routine tasks related to live line maintenance. Stability and telepresence are the main issues in reference to bilateral control. Three stable bilateral control schemes are designed for haptic teleoperation of hydraulic actuators considering nonlinear dynamics of hydraulic actuation, haptic device, and the operator. For each control scheme, stability of the entire control system is proven theoretically by constructing a proper Lyapunov function. Due to the discontinuity originating from a sign function in the control laws, the proposed control systems are non-smooth. Thus, the existence, continuation, and uniqueness of Filippov’s solution to the system are first proven for each control system. Next, the extensions of Lyapunov’s stability theory to non-smooth systems and LaSalle’s invariant set theorems are employed to prove the asymptotic stability of the control systems. In terms of telepresence, two types of haptic sensation are provided to the operator: (i) haptic based on the reflected interaction force, and (ii) haptic based on the position error. Performances of all proposed controllers are validated by experimental results on a hydraulic actuator controlled by a haptic device. It is shown that besides stability, the hydraulic actuator performs well in terms of position tracking while the haptic device provides telepresence for the operator.

Hydraulic manipulators commonly interact with environments that are highly unstructured, and thus rely on the intelligence of human operators to provide proper commands. Typically, operators use visual information, directly or through cameras, to perform a task. Providing haptic or touch sensation about the task environment to the operator, enhances her/his ability to perform telemanipulation. The focus of this thesis is on haptic teleoperation of hydraulic manipulators. The application is directed at live transmission line maintenance tasks. In this thesis, both unilateral and bilateral haptic teleoperation of hydraulic manipulators are investigated. On the unilateral telemanipulation front, position error is shown to be an important issue in performing repetitive tasks. The most important sources of inaccuracy in position are sensors, robot controller performance, and the operator. To reduce the human operator’s errors, the concept of virtual fixtures is adopted in this research. It is shown that virtual fixtures can help operators perform routine tasks related to live line maintenance. Stability and telepresence are the main issues in reference to bilateral control. Three stable bilateral control schemes are designed for haptic teleoperation of hydraulic actuators considering nonlinear dynamics of hydraulic actuation, haptic device, and the operator. For each control scheme, stability of the entire control system is proven theoretically by constructing a proper Lyapunov function. Due to the discontinuity originating from a sign function in the control laws, the proposed control systems are non-smooth. Thus, the existence, continuation, and uniqueness of Filippov’s solution to the system are first proven for each control system. Next, the extensions of Lyapunov’s stability theory to non-smooth systems and LaSalle’s invariant set theorems are employed to prove the asymptotic stability of the control systems. In terms of telepresence, two types of haptic sensation are provided to the operator: (i) haptic based on the reflected interaction force, and (ii) haptic based on the position error. Performances of all proposed controllers are validated by experimental results on a hydraulic actuator controlled by a haptic device. It is shown that besides stability, the hydraulic actuator performs well in terms of position tracking while the haptic device provides telepresence for the operator.

Examensarbetet kommer att göra en jämförande analys av driftsäkerhet med trådade signaler till en Remote Terminal Unit (RTU) och en Programmable Logic Controller (PLC) med busstyrning. Rapporten genomfördes som ett uppdrag av Skellefteå Kraft AB för att se om det möjligt att byta till PLC- med busstyrning. Rapporten redogör för grundläggande beskrivning för skillnaden mellan de här två system och kommer att undersöka vilken som är driftsäkrare och lönsammare med hänsyn till krav enligt Svenska Kraftföretagens riktlinjer för dammsäkerhet (Ridas).Med hjälp av kurslitteratur, ABB handboken, internet websidor samt intervjuar med Skellefteå Kraft AB:s personal har arbetets resultat visat att busstyrning med PLC kommer att fungera driftsäkert samt kommer att bli lönsamt jämfört med trådade signaler till RTU. Resultat visat även att det finns ingenting som hindrar att installera busstyrning enligt Ridas men vissa funktioner bör installeras. Rapporten är avgränsat genom att inte ta upp eventuella krav från miljöbalken. / This thesis will make a comparative analysis of the operation safety of the wire connection to Remote Terminal Unit (RTU) and Programmable Logic Controller (PLC) with bus-controller. The report describes the basic description of the difference between these two systems and will explore which is safer and more economic with consideration to qualification according to Swedish energy companies' guidelines for dam safety (Ridas).Through course literature, ABB Bok, internet web sits and interviews with Skellefteå Kraft AB staff the result of this report have been created.The report results prove that PLC with bus-controller will operate operationally safe and profitable compared to wire connection to RTU. Results also showed that there is nothing which prevents to install bus-controller according to RIDAS but certain features should be installed.

The diploma´s thesis is focussed on principles and characteristics of Powerline Communication. Powerline communication is a technology using powerlines for transmitting information. Its narrowband variant is developing in the field of remote data reading nowadays. There is a lot of solutions that need to be tested and simulated prior ro putting into practice. This thesis deals with preparing the OMNeT++ simulation enviroment for purposes of simulating the narrowband service PLC.

This master's thesis deals with a narrowband power line communication technology (PLC) and focuses on the potential use in the sensor networks. This thesis addresses both the structure and basic properties of PLC standard and possible use of this application in practice. The main part of this work is implementation of the PLC networks with IC ST7570 of STMicroelectronics. As an example of practical use of PLC technology, this network is connected to the computer where the data from the sensor (meter) connected to a PLC modem, stored in a database using a PHP script as presented by the Internet. Problem solving in this thesis focuses primarily on the simplicity and universality of the resulting applications.