Enhancing the environmental sustainability of IT

Emerging technologies for learning report - Article exploring green I

Systems study for an Integrated Digital-Electric Aircraft (IDEA)

The results of the Integrated Digital/Electric Aircraft (IDEA) Study are presented. Airplanes with advanced systems were, defined and evaluated, as a means of identifying potential high payoff research tasks. A baseline airplane was defined for comparison, typical of a 1990's airplane with advanced active controls, propulsion, aerodynamics, and structures technology. Trade studies led to definition of an IDEA airplane, with extensive digital systems and electric secondary power distribution. This airplane showed an improvement of 3% in fuel use and 1.8% in DOC relative to the baseline configuration. An alternate configuration, an advanced technology turboprop, was also evaluated, with greater improvement supported by digital electric systems. Recommended research programs were defined for high risk, high payoff areas appropriate for implementation under NASA leadership

Electrical Loads and Power Systems for the DEMO Nuclear Fusion Project

EU-DEMO is a European project, having the ambitious goal to be the first demonstrative power plant based on nuclear fusion. The electrical power that is expected to be produced is in the order of 700–800 MW, to be delivered via a connection to the European High Voltage electrical grid. The initiation and control of fusion processes, besides the problems related to the nuclear physics, need very complex electrical systems. Moreover, also the conversion of the output power is not trivial, especially because of the inherent discontinuity in the EU-DEMO operations. The present article concerns preliminary studies for the feasibility and realization of the nuclear fusion power plant EU-DEMO, with a special focus on the power electrical systems. In particular, the first stage of the study deals with the survey and analysis of the electrical loads, starting from the steady-state loads. Their impact is so relevant that could jeopardy the efficiency and the convenience of the plant itself. Afterwards, the loads are inserted into a preliminary internal distribution grid, sizing the main electrical components to carry out the power flow analysis, which is based on simulation models implemented in the DIgSILENT PowerFactory software

Remote real-time monitoring of subsurface landfill gas migration

The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months

The presentation of sustainable power source assets in the field of intensity age assumes an imperative job

DC to DC converters to interface lesser-voltage higher-control supply to the essential stock shows the most raised proficiency was practiced in the full-connect converter. Non-separated converters bury unified inductor help converters with essential voltage gain and furthermore converters hold lesser profitability, yet they huge in structure, even the quantity of latent parts is diminished. In like manner gives proficient utilization of semiconductor switches, have higher voltage yield and are prepared to work in lesser estimation of D interestingly with every single disconnected converter. High addition topologies are regularly outfitted with high voltage security structures. Few non-disengaged topologies gives voltage hang security circuits are pointless since capacitive fragments and circuit plan are progressed to work under higher information voltage and low power. That requires lesser qualities for convincing RAC obstruction and entomb partnered inductance dispersal to achieve more prominent adequacy of intensity change. Larger supply current needs extensive region of core area inter allied inductors

A Two Stage Stand Alone Solar PV System

Stand-alone systems based on solar photovoltaic (PV) have developed as a sustainable alternative pertaining to issue of electrification in areas particularly where the grid is not present. Main challenges in scheming this kind of systems are 1) Maximum power extraction from PV array 2) Dc to ac conversion 3) Protecting battery from over discharging and overcharging and 4) Facilitating satisfactory stepping up of voltage. As many objectives are needed to be met, schemes hitherto for standalone systems need a minimum of three converter stages, resulting in significant decline in efficiency and reliability of system. To tackle this problem, a two stage stand-alone topology comprising a novel transformer coupled dual input converter (TCDIC) is connected to a normal full bridge inverter is discussed in this thesis. Discussed TCDIC can facilitate charge control of battery while tracking maximum power point and keeping proper voltage level at load terminal. Mathematical model of TCDIC through small signal based approach is also included. A suitable control strategy for TCDIC is also presented to generate pulses. The operational efficiency of this topology is verified by performing simulation studies in detail

Low-power switched capacitor voltage reference

Low-power analog design represents a developing technological trend as it emerges from a rather limited range of applications to a much wider arena affecting mainstream market segments. It especially affects portable electronics with respect to battery life, performance, and physical size. Meanwhile, low-power analog design enables technologies such as sensor networks and RFID. Research opportunities abound to exploit the potential of low power analog design, apply low-power to established fields, and explore new applications. The goal of this effort is to design a low-power reference circuit that delivers an accurate reference with very minimal power consumption. The circuit and device level low-power design techniques are suitable for a wide range of applications. To meet this goal, switched capacitor bandgap architecture was chosen. It is the most suitable for developing a systematic, and groundup, low-power design approach. In addition, the low-power analog cell library developed would facilitate building a more complex low-power system. A low-power switched capacitor bandgap was designed, fabricated, and fully tested. The bandgap generates a stable 0.6-V reference voltage, in both the discrete-time and continuous-time domain. The system was thoroughly tested and individual building blocks were characterized. The reference voltage is temperature stable, with less than a 100 ppm/°C drift, over a --60 dB power supply rejection, and below a 1 [Mu]A total supply current (excluding optional track-and-hold). Besides using it as a voltage reference, potential applications are also described using derivatives of this switched capacitor bandgap, specifically supply supervisory and on-chip thermal regulation

Power Management Electronics

Accepted versio

Power extraction circuits for piezoelectric energy harvesters and time series data in water supply systems

This thesis investigates two fundamental technological challenges that prevent water utilities from deploying infrastructure monitoring apparatus with high spatial and temporal resolution: providing sufficient power for sensor nodes by increasing the power output from a vibration-driven energy harvester based on piezoelectric transduction, and the processing and storage of large volumes of data resulting from the increased level of pressure and flow rate monitoring. Piezoelectric energy harvesting from flow-induced vibrations within a water main represents a potential source of power to supply a sensor node capable of taking high- frequency measurements. A main factor limiting the amount of power from a piezoelectric device is the damping force that can be achieved. Electronic interface circuits can modify this damping in order to increase the power output to a reasonable level. A unified analytical framework was developed to compare circuits able to do this in terms of their power output. A new circuit is presented that out-performs existing circuits by a factor of 2, which is verified experimentally. The second problem concerns the management of large data sets arising from resolving challenges with the provision of power to sensor devices. The ability to process large data volumes is limited by the throughput of storage devices. For scientists to execute queries in a timely manner, query execution must be performant. The large volume of data that must be gathered to extract information from historic trends mandates a scalable approach. A scalable, durable storage and query execution framework is presented that is able to significantly improve the execution time of user-defined queries. A prototype database was implemented and validated on a cluster of commodity servers using live data gathered from a London pumping station and transmission mains. Benchmark results and reliability tests are included that demonstrate a significant improvement in performance over a traditional database architecture for a range of frequently-used operations, with many queries returning results near-instantaneously