Performance Evaluation of Lighting Fixtures and Installations for Renewable Energy Applications

Energy efficiency has been viewed as the most accessible and cost effective form of alternative energy. While lighting occupies only a percentage in the total electric loads in homes, technological advances in Light Emitting Diodes (LED) are becoming more convincing in their power consumption and lumens output. This paper evaluates the percentage lighting occupied in the total load spectrum on the two main buildings in Osun State University, verifies the light level in the library reading rooms (a place where adequate lighting is imperative) with recommended standards and comparison between the output of Compact Fluorescent Lamps (CFL) and the LEDs. Walk-through Energy audit approach was used to evaluate the percentage lightning occupies which involves identification and grouping of all electrical loads with their respective power rating in Watts. Similarly, illumination level verification campaign was conducted with the use of a digital light meter (sensor based device) connected to a Personal Computer for logging illumination level real time along the aisles and reading cubicles. The same light meter was used for comparing the output of installed CFL and proposed LED. Results indicate that lighting fixtures occupy 12.2% of the load spectrum. The lighting installations also do not conform to global illumination standards for the facility accessed while the output of the LED tested is still low. It is therefore recommended that better LED light sources be considered for efficient energy, reduction in environmental pollution associated with power generation, reduction in power needed to maintain a cooling effect and cost economy. Keywords: CFL, LEDs, lumens, illumination level verification, power sector, environmental pollution

Analysis and design considerations of a high-power density, dual air gap, axial-field, brushless, permanent magnet motor

Until recently, brush dc motors have been the dominant drive system because they provide easily controlled motor speed over a wide range, rapid acceleration and deceleration, convenient control of position, and lower product cost. Despite these capabilities, the brush dc motor configuration does not satisfy the design requirements for the U.S. Navy\u27s underwater propulsion applications. Technical advances in rare-earth permanent magnet materials, in high-power semiconductor transistor technology, and in various rotor position-sensing devices have made using brushless permanent magnet motors a viable alternative. This research investigates brushless permanent magnet motor technology, studying the merits of dual-air gap, axial-field, brushless, permanent magnet motor configuration in terms of power density, efficiency, and noise/vibration levels. Because the design objectives for underwater motor applications include high-power density, high-performance, and low-noise/vibration, the traditional, simplified equivalent circuit analysis methods to assist in meeting these goals were inadequate. This study presents the development and verification of detailed finite element analysis (FEA) models and lumped parameter circuit models that can calculate back electromotive force waveforms, inductance, cogging torque, energized torque, and eddy current power losses. It is the first thorough quantification of dual air-gap, axial-field, brushless, permanent magnet motor parameters and performance characteristics. The new methodology introduced in this research not only facilitates the design process of an axial field, brushless, permanent magnet motor but reinforces the idea that the high-power density, high-efficiency, and low-noise/vibration motor is attainable

Perspectives on energy storage wheels for space station application

Several of the issues of the workshop are addressed from the perspective of a potential Space Station developer and energy wheel user. Systems' considerations are emphasized rather than component technology. The potential of energy storage wheel (ESW) concept is discussed. The current status of the technology base is described. Justification for advanced technology development is also discussed. The study concludes that energy storage in wheels is an attractive concept for immediate technology development and future Space Station application

Compressed sensing using sparse binary measurements: a rateless coding perspective

Compressed Sensing (CS) methods using sparse binary measurement matrices and iterative message-passing re- covery procedures have been recently investigated due to their low computational complexity and excellent performance. Drawing much of inspiration from sparse-graph codes such as Low-Density Parity-Check (LDPC) codes, these studies use analytical tools from modern coding theory to analyze CS solutions. In this paper, we consider and systematically analyze the CS setup inspired by a class of efficient, popular and flexible sparse-graph codes called rateless codes. The proposed rateless CS setup is asymptotically analyzed using tools such as Density Evolution and EXIT charts and fine-tuned using degree distribution optimization techniques

Reconfigurable Mobile Multimedia Systems

This paper discusses reconfigurability issues in lowpower hand-held multimedia systems, with particular emphasis on energy conservation. We claim that a radical new approach has to be taken in order to fulfill the requirements - in terms of processing power and energy consumption - of future mobile applications. A reconfigurable systems-architecture in combination with a QoS driven operating system is introduced that can deal with the inherent dynamics of a mobile system. We present the preliminary results of studies we have done on reconfiguration in hand-held mobile computers: by having reconfigurable media streams, by using reconfigurable processing modules and by migrating functions