Hybrid behavioral-analytical loss model for a high frequency and low load DC/DC buck converter

This work presents a behavioral-analytical hybrid loss model for a buck converter. The model has been designed for a wide operating frequency range up to 4MHz and a low power range (below 20W). It is focused on the switching losses obtained in the power MOSFETs. Main advantages of the model are the fast calculation time (below 8.5 seconds) and a good accuracy, which makes this model suitable for the optimization process of the losses in the design of a converter. It has been validated by simulation and experimentally with one GaN power transistor and three Si MOSFETs. Results show good agreement between measurements and the model

Envelope Amplifier Based on a Hybrid Series Converter With The Slow-envelope Technique

High frequency dc-dc switching converters are used as envelope amplifiers in RF transmitters. The dc-dc converter should operate at very high frequency to track an envelope in the MHz range to supply the power amplifier. One of the circuits suitable for this application is a hybrid topology composed of a switched converter and a linear regulator in series that work together to adjust the output voltage to track the envelope with accuracy. This topology can take advantage of the reduced slew-rate technique where switching dc-dc converter provides the RF envelope with limited slew rate in order to avoid high switching frequency and high power losses, while the linear regulator performs fine adjustment in order to obtain the exact replica of the RF envelope. The combination of this control technique with this topology is proposed in this paper. Envelopes with different bandwidth will be considered to optimize the efficiency of the dc-dc converter. The calculations and experiments have been done to track a 2MHz envelope in the range 0-12V for an EER RF transmitter.

Energy consumption and intensity of toll highway transport in Spain

We estimate the energy consumption of toll highway transport on a number of Spanish roads. Regression parameters are balanced according to coefficients from an empirical analysis based on survey data by vehicle type. The mean energy consumption and subsequent CO2 emissions on the toll highway sections are estimated as 1895 MJ/h/lane-km and 0.15 tCO2 eq./h/lane-km, values that increase to 2644 and 0.22 when energy and carbon emissions of transport infrastructure are considered based on the life cycle energy consumption for toll highway construction and use. If the energy intensity of infrastructure construction is allocated to the users according to traffic, it is much higher for motorcycles than for cars, and is significantly lower for articulated trucks than for vans.

Evaluation of the Magnetic Field Generated by the Inverter of an Electric Vehicle

In hybrid and electric vehicles, passengers sit very close to an electric system of significant power, which means that they may be subjected to high electromagnetic fields. The hazards of long-term exposure to these fields must be taken into account when designing electric vehicles and their components. Among all the electric devices present in the power train, the electronic converter is the most difficult to analyze, given that it works with different frequencies. In this paper, a methodology to evaluate the magnetic field created by a power electronics converter is proposed. After a brief overview of the recommendations of electromagnetic fields exposure, the magnetic field produced by an inverter is analyzed using finite element techniques. The results obtained are compared to laboratory measurements, taken from a real inverter, in order to validate the model. Finally, results are used to draw some conclusions regarding vehicle design criteria and magnetic shielding efficiency.

Nationwide impact and vehicle to grid application of electric vehicles mobility using an activity based model

This paper describes the impact of electric mobility on the transmission grid in Flanders region (Belgium), using a micro-simulation activity based models. These models are used to provide temporal and spatial estimation of energy and power demanded by electric vehicles (EVs) in different mobility zones. The increment in the load demand due to electric mobility is added to the background load demand in these mobility areas and the effects over the transmission substations are analyzed. From this information, the total storage capacity per zone is evaluated and some strategies for EV aggregator are proposed, allowing the aggregator to fulfill bids on the electricity markets.

Evaluation of the utilization of electric vehicles for building energy management in hotels

Governments are working in new policies to slow down total energy consumption and greenhouse gases (GHG) emissions, promoting the deployment of electric vehicles (EVs) in all countries. In order to facilitate this deployment and help to reduce the final costs of their batteries, additional utilization of EVs when those are parked has been proposed. EVs can be used to minimize the total electricity cost of buildings (named vehicle to building applications, V2B). In this paper an economic evaluation of EVs in the Building Energy Management System is shown. The optimal storage capacity and its equivalent number of EVs are determined. This value is then used for determining the optimal charging schedule to be applied to the batteries. From this schedule, the total expected profit is derived for the case of a real hotel in Spain.

Mechanical behavior and failure micromechanisms of hybrid 3D woven composites in tension

The deformation and failure micromechanisms of a hybrid 3D woven composite were studied in tension. Plain and open-hole composite coupons were tested in tension until failure in the fill and warp directions, as well as fiber tows extracted from the dry fabric and impregnated with the matrix. The macroscopic evolution of damage in the composite coupons was assessed by means of periodic unloading���reloading (to obtain the elastic modulus and the residual strain), whereas the microscopic mechanism were established by means of X-ray computed microtomography. To this end, specimens were periodically removed from the mechanical testing machine and infiltrated with ZnI-containing liquid to assess the main damage modes as a function of the applied strain. The experimental observations and the predictions of an isostrain model were used to understand the key factors controlling the elastic modulus, strength and notch sensitivity of hybrid 3D woven composites in tension. It was found that the full contribution of the glass fibers to the composite strength was not employed, due to the premature fracture of the carbon fibers, but their presence increased the fracture strain and the energy dissipated during fracture. Thus, hybridization of the 3D woven composite led to a notch-insensitive behavior as demonstrated by open-hole tests

Conceptual design of offshore platform supply vessel based on hybrid diesel generator-fuel cell power plant

Nowadays increasing fuel prices and upcoming pollutant emission regulations are becoming a growing concern for the shipping industry worldwide. While fuel prices will keep rising in future years, the new International Convention for the Prevention of Pollution from Ships (MARPOL) and Sulphur Emissions Control Areas (SECA) regulations will forbid ships to use heavy fuel oils at certain situations. To fulfil with these regulations, the next step in the marine shipping business will comprise the use of cleaner fuels on board as well as developing new propulsion concept. In this work a new conceptual marine propulsion system is developed, based on the integration of diesel generators with fuel cells in a 2850 metric tonne of deadweight platform supply vessel. The efficiency of the two 250 kW methanol-fed Solid Oxide Fuel Cell (SOFC) system installed on board combined with the hydro dynamically optimized design of the hull of the ship will allow the ship to successfully operate at certain modes of operation while notably reduce the pollutant emissions to the atmosphere. Besides the cogeneration heat obtained from the fuel cell system will be used to answer different heating needs on board the vessel

Towards energy sustainability in ecolodges for latin America: a case in the bolivian Amazon

This project, funded by the Programa Iberoam��ricano de Ciencia y Tecnolog��a para el Desarrollo (CYTED), analyses the energy service requirements in sustainable tourism and will spread knowledge about renewable energies among the ecotourism stakeholders of Latin America. The target groups are local communities in protected areas, because they are the less up to date groups and, frequently, they are living in the most fragile ecosystems, but also the most fertile in biodiversity; their living standard is very low and the ecotourism can be a successful economic resource. The regions considered are ecosystems in Latin America, which have some protection degree, and are managed by local communities. The selected countries to implement renewable energy infrastructures in ecolodges are: Bolivia, Ecuador and Peru. Also low cost telecommunications infrastructures will be installed to improve the diffusion among potential clients of the ecolodges, in order to permit direct reservation of the services.

Reducing the impact of EV charging on the electric grid

One of the main objectives of European Commission related to climate and energy is the well-known 20-20-20 targets to be achieved in 2020: Europe has to reduce greenhouse gas emissions of at least 20% below 1990 levels, 20% of EU energy consumption has to come from renewable resources and, finally, a 20% reduction in primary energy use compared with projected levels, has to be achieved by improving energy efficiency. In order to reach these objectives, it is necessary to reduce the overall emissions, mainly in transport (reducing CO2, NOx and other pollutants), and to increase the penetration of the intermittent renewable energy. A high deployment of battery electric (BEVs) and plug-in hybrid electric vehicles (PHEVs), with a low-cost source of energy storage, could help to achieve both targets. Hybrid electric vehicles (HEVs) use a combination of a conventional internal combustion engine (ICE) with one (or more) electric motor. There are different grades of hybridation from micro-hybrids with start-stop capability, mild hybrids (with kinetic energy recovery), medium hybrids (mild hybrids plus energy assist) and full hybrids (medium hybrids plus electric launch capability). These last types of vehicles use a typical battery capacity around 1-2 kWh. Plug in hybrid electric vehicles (PHEVs) use larger battery capacities to achieve limited electric-only driving range. These vehicles are charged by on-board electricity generation or either plugging into electric outlets. Typical battery capacity is around 10 kWh. Battery Electric Vehicles (BEVs) are only driven by electric power and their typical battery capacity is around 15-20 kWh. One type of PHEV, the Extended Range Electric Vehicle (EREV), operates as a BEV until its plug-in battery capacity is depleted; at which point its gasoline engine powers an electric generator to extend the vehicle's range. The charging of PHEVs (including EREVs) and BEVs will have different impacts to the electric grid, depending on the number of vehicles and the start time for charging. Initially, the lecture will start analyzing the electrical power requirements for charging PHEVs-BEVs in Flanders region (Belgium) under different charging scenarios. Secondly and based on an activity-based microsimulation mobility model, an efficient method to reduce this impact will be presented.

Development of a full hybrid lighting-CPV prototype and savings in a real case operation

A full Hybrid lighting-CPV prototype has been assembled. This new concept mixes a classical CPV module with the production of light for illumination without a double conversion (solar energy to electricity and electricity to light) allowing a higher efficiency to the whole system. The present prototype is based on a commercial CPV module that has been adapted in order to be hybrid, adjusting the receivers to pass the fibers into the module, inserting a holder to adjust x,y and z position of the fibers and changing the original parquet of lenses by a bifocal one composed most of the original lenses and the inclusion of other lenses in the position of the corners. Results show that with a minimal loss in the CPV part, a luminous flux is obtained that can be used to illuminate. Adding an additional electrical lamp and a light sensor that enables this lamp when no light from the sun is received, a 38% saving on lighting electricity is expected in Madrid during a year.

Hybrid wind-diesel power plant valuation and optimization using real option theory and dynamic programming

El sistema de energ��a e��lica-diesel h��brido tiene un gran potencial en la prestaci��n de suministro de energ��a a comunidades remotas. En comparaci��n con los sistemas tradicionales de diesel, las plantas de energ��a h��bridas ofrecen grandes ventajas tales como el suministro de capacidad de energ��a extra para "microgrids", reducci��n de los contaminantes y emisiones de gases de efecto invernadero, y la cobertura del riesgo de aumento inesperado del precio del combustible. El principal objetivo de la presente tesis es proporcionar nuevos conocimientos para la evaluaci��n y optimizaci��n de los sistemas de energ��a h��brido e��lico-diesel considerando las incertidumbres. Dado que la energ��a e��lica es una variable estoc��stica, ��sta no puede ser controlada ni predecirse con exactitud. La naturaleza incierta del viento como fuente de energ��a produce serios problemas tanto para la operaci��n como para la evaluaci��n del valor del sistema de energ��a e��lica-diesel h��brido. Por un lado, la regulaci��n de la potencia inyectada desde las turbinas de viento es una dif��cil tarea cuando opera el sistema h��brido. Por otro lado, el bene.cio econ��mico de un sistema e��lico-diesel h��brido se logra directamente a trav��s de la energ��a entregada a la red de alimentaci��n de la energ��a e��lica. Consecuentemente, la incertidumbre de los recursos e��licos incrementa la dificultad de estimar los beneficios globales en la etapa de planificaci��n. La principal preocupaci��n del modelo tradicional determinista es no tener en cuenta la incertidumbre futura a la hora de tomar la decisi��n de operaci��n. Con lo cual, no se prev�� las acciones operativas flexibles en respuesta a los escenarios futuros. El an��lisis del rendimiento y simulaci��n por ordenador en el Proyecto E��lico San Crist��bal demuestra que la incertidumbre sobre la energ��a e��lica, las estrategias de control, almacenamiento de energ��a, y la curva de potencia de aerogeneradores tienen un impacto significativo sobre el rendimiento del sistema. En la presente tesis, se analiza la relaci��n entre la teor��a de valoraci��n de opciones y el proceso de toma de decisiones. La opci��n real se desarrolla con un modelo y se presenta a trav��s de ejemplos pr��cticos para evaluar el valor de los sistemas de energ��a e��lica-diesel h��bridos. Los resultados muestran que las opciones operacionales pueden aportar un valor adicional para el sistema de energ��a h��brida, cuando esta flexibilidad operativa se utiliza correctamente. Este marco se puede aplicar en la optimizaci��n de la operaci��n a corto plazo teniendo en cuenta la naturaleza dependiente de la trayectoria de la pol��tica ��ptima de despacho, dadas las plausibles futuras realizaciones de la producci��n de energ��a e��lica. En comparaci��n con los m��todos de valoraci��n y optimizaci��n existentes, el resultado del caso de estudio num��rico muestra que la pol��tica de operaci��n resultante del modelo de optimizaci��n propuesto presenta una notable actuaci��n en la reducci��n del con- sumo total de combustible del sistema e��lico-diesel. Con el .n de tomar decisiones ��ptimas, los operadores de plantas de energ��a y los gestores de ��stas no deben centrarse s��lo en el resultado directo de cada acci��n operativa, tampoco deber��an tomar decisiones deterministas. La forma correcta es gestionar din��micamente el sistema de energ��a teniendo en cuenta el valor futuro condicionado en cada opci��n frente a la incertidumbre. ABSTRACT Hybrid wind-diesel power systems have a great potential in providing energy supply to remote communities. Compared with the traditional diesel systems, hybrid power plants are providing many advantages such as providing extra energy capacity to the micro-grid, reducing pollution and greenhouse-gas emissions, and hedging the risk of unexpected fuel price increases. This dissertation aims at providing novel insights for assessing and optimizing hybrid wind-diesel power systems considering the related uncertainties. Since wind power can neither be controlled nor accurately predicted, the energy harvested from a wind turbine may be considered a stochastic variable. This uncertain nature of wind energy source results in serious problems for both the operation and value assessment of the hybrid wind-diesel power system. On the one hand, regulating the uncertain power injected from wind turbines is a difficult task when operating the hybrid system. On the other hand, the economic profit of a hybrid wind-diesel system is achieved directly through the energy delivered to the power grid from the wind energy. Therefore, the uncertainty of wind resources has increased the difficulty in estimating the total benefits in the planning stage. The main concern of the traditional deterministic model is that it does not consider the future uncertainty when making the dispatch decision. Thus, it does not provide flexible operational actions in response to the uncertain future scenarios. Performance analysis and computer simulation on the San Cristobal Wind Project demonstrate that the wind power uncertainty, control strategies, energy storage, and the wind turbine power curve have a significant impact on the performance of the system. In this dissertation, the relationship between option pricing theory and decision making process is discussed. A real option model is developed and presented through practical examples for assessing the value of hybrid wind-diesel power systems. Results show that operational options can provide additional value to the hybrid power system when this operational flexibility is correctly utilized. This framework can be applied in optimizing short term dispatch decisions considering the path-dependent nature of the optimal dispatch policy, given the plausible future realizations of the wind power production. Comparing with the existing valuation and optimization methods, result from numerical example shows that the dispatch policy resulting from the proposed optimization model exhibits a remarkable performance in minimizing the total fuel consumption of the wind-diesel system. In order to make optimal decisions, power plant operators and managers should not just focus on the direct outcome of each operational action; neither should they make deterministic decisions. The correct way is to dynamically manage the power system by taking into consideration the conditional future value in each option in response to the uncertainty.

Adapting micro-economy of energy corporations to macroeconomy policies aiming at a sustainable economy

Esta Tesis surgi�� ante la intensidad y verosimilitud de varias se��ales o ���warnings��� asociadas a pol��ticas dirigidas a reducir el peso del petr��leo en el sector energ��tico, tanto por razones econ��micas, como geopol��ticas, como ambientales. Como tal Tesis se consolid�� al ir incorporando elementos novedosos pero esenciales en el mundo petrol��fero, particularmente las ���tecnolog��as habilitantes���, tanto de incidencia directa, como el ���fracking��� como indirecta, del cual es un gran ejemplo el Veh��culo El��ctrico (puro). La Tesis se defini�� y estructur�� para elaborar una serie de indagaciones y disquisiciones, que comportaran un conjunto de conclusiones que fueran ��tiles para las corporaciones energ��ticas. Tambi��n para la comprensi��n de la propia evoluci��n del sector y de sus prestaciones t��cnicas y econ��micas, de cara a dar el servicio que los usuarios finales piden. Dentro de las tareas anal��ticas y reflexivas de la Tesis, se acu��aron ciertos t��rminos conceptuales para explicar m��s certeramente la realidad del sector, y tal es el caso del ���Investment burden���, que pondera la inversi��n espec��fica (���/W) requerida por una instalaci��n, con la duraci��n del per��odo de construcci��n y los riesgos tanto tangibles como regulatorios. Junto a ello la Tesis propone una herramienta de estudio y prognosis, denominada ���Market integrated energy efficiency���, especialmente aplicable a dicotom��as. Tal es el caso del coche t��rmico, versus coche el��ctrico. El objetivo es optimizar una determinada actividad energ��tica, o la productividad total del sector. Esta Tesis propone varias innovaciones, que se pueden agrupar en dos niveles: el primero dentro del campo de la Energ��a, y el segundo dentro del campo de las corporaciones, y de manera especial de las corporaciones del sector hidrocarburos. A nivel corporativo, la adaptaci��n a la nueva realidad ser�� funci��n directa de la capacidad de cada corporaci��n para desarrollar y/o comprar las tecnolog��as que permitan mantener o aumentar cuota de mercado. Las conclusiones de la Tesis apuntan a tres opciones principalmente para un replanteamiento corporativo: - Diversificaci��n energ��tica - Desplazamiento geogr��fico - Benefici��ndose de posibles nuevos nichos tecnol��gicos, como son: ��� En upstream: Recuperaci��n estimulada de petr��leo mediante uso de energ��as renovables ��� En downstream: Aditivos orientados a reducir emisiones ��� En gesti��n del cambio: Almacenamiento energ��tico con fines operativos Algunas pol��ticas energ��ticas siguen la tendencia de crecimiento cero de algunos pa��ses de la OCDE. No obstante, la realidad mundial es muy diferente a la de esos pa��ses. Por ejemplo, seg��n diversas estimaciones (basadas en bancos de datos solventes, referenciados en la Tesis) el n��mero de veh��culos aumentar�� desde aproximadamente mil millones en la actualidad hasta el doble en 2035; mientras que la producci��n de petr��leo s��lo aumentar�� de 95 a 145 millones de barriles al d��a. Un aumento del 50% frente a un aumento del 100%. Esto generar�� un curioso desajuste, que se empezar�� a sentir en unos pocos a��os. Las empresas y corporaciones del sector hidrocarburos pueden perder el monopolio que atesoran actualmente en el sector transporte frente a todas las dem��s fuentes energ��ticas. Esa p��rdida puede quedar compensada por una mejor gesti��n de todas sus capacidades y una participaci��n m��s integrada en el mundo de la energ��a, buscando sinergias donde hasta ahora no hab��a sino distanciamiento. Los productos petrol��feros pueden alimentar cualquier tipo de maquina t��rmica, como las turbinas Brayton, o alimentar reformadores para la producci��n masiva de H2 para su posterior uso en pilas combustible. El almacenamiento de productos derivados del petr��leo no es ning��n reto ni plantea problema alguno; y sin embargo este almacenamiento es la llave para resolver muchos problemas. Es posible que el comercio de petr��leo se haga menos vol��til debido a los efectos asociados al almacenamiento; pero lo que es seguro es que la eficiencia energ��tica de los usos de ese petr��leo ser�� m��s elevada. La Tesis part��a de ciertas amenazas sobre el futuro del petr��leo, pero tras el an��lisis realizado se puede vislumbrar un futuro prometedor en la fusi��n de pol��ticas medioambientales coercitivas y las nuevas tecnolog��as emergentes del actual portafolio de oportunidades t��cnicas. ABSTRACT This Thesis rises from the force and the credibility of a number of warning signs linked to policies aimed at reducing the role of petroleum in the energy industry due to economical, geopolitical and environmental drives. As such Thesis, it grew up based on aggregating new but essentials elements into the petroleum sector. This is the case of ���enabling technologies��� that have a direct impact on the petroleum industry (such as fracking), or an indirect but deep impact (such as the full electrical vehicle). The Thesis was defined and structured in such a way that could convey useful conclusions for energy corporations through a series of inquiries and treatises. In addition to this, the Thesis also aims at understating la evolution of the energy industry and its capabilities both technical and economical, towards delivering the services required by end users. Within the analytical task performed in the Thesis, new terms were coined. They depict concepts that aid at explaining the facts of the energy industry. This is the case for ���Investment burden���, it weights the specific capital investment (���/W) required to build a facility with the time that takes to build it, as well as other tangible risks as those posed by regulation. In addition to this, the Thesis puts forward an application designed for reviewing and predicting: the so called ���Market integrated energy efficiency���, especially well-suited for dichotomies, very appealing for the case of the thermal car versus the electric car. The aim is to optimize energy related activity; or even the overall productivity of the system. The innovations proposed in this Thesis can be classified in two tiers. Tier one, within the energy sector; and tier two, related to Energy Corporation in general, but with oil and gas corporations at heart. From a corporate level, the adaptation to new energy era will be linked with the corporation capability to develop or acquire those technologies that will yield to retaining or enhancing market share. The Thesis highlights three options for corporate evolution: - diversification within Energy - geographic displacement - profiting new technologies relevant to important niches of work for the future, as: o Upstream: enhanced oil recovery using renewable energy sources (for upstream companies in the petroleum business) o Downstream: additives for reducing combustion emissions o Management of Change: operational energy storage Some energy policies tend to follow the zero-growth of some OECD countries, but the real thing could be very different. For instance, and according to estimates the number of vehicles in use will grow from 1 billion to more than double this figure 2035; but oil production will only grow from 95 million barrel/day to 145 (a 50% rise of versus an intensification of over a 100%). Hydrocarbon Corporation can lose the monopoly they currently hold over the supply of energy to transportation. This lose can be mitigated through an enhanced used of their capabilities and a higher degree of integration in the world of energy, exploring for synergies in those places were gaps were present. Petroleum products can be used to feed any type of thermal machine, as Brayton turbines, or steam reformers to produce H2 to be exploited in fuel cells. Storing petroleum products does not present any problem, but very many problems can be solved with them. Petroleum trading will likely be less volatile because of the smoothing effects of distributed storage, and indeed the efficiency in petroleum consumption will be much higher. The Thesis kicked off with a menace on the future of petroleum. However, at the end of the analysis, a bright future can be foreseen in the merging between highly demanding environmental policies and the relevant technologies of the currently emerging technical portfolio.

Hybrid thermionic-photovoltaic converter

A conceptual device for the direct conversion of heat into electricity is presented. This concept hybridizes thermionic (TI) and thermophotovoltaic (TPV) energy conversion in a single thermionic-photovoltaic (TIPV) solid-state device. This device transforms into electricity both the electron and photon fluxes emitted by an incandescent surface. This letter presents an idealized analysis of this device in order to determine its theoretical potential. According to this analysis, the key advantage of this converter, with respect to either TPV or TI, is the higher power density in an extended temperature range. For low temperatures, TIPV performs like TPV due to the negligible electron flux. On the contrary, for high temperatures, TIPV performs like TI due to the great enhancement of the electron flux, which overshadows the photon flux contribution. At the intermediate temperatures, 1650K in the case of this particular study, I show that the power density potential of TIPV converter is twice as great as that of TPV and TI. The greatest impact concerns applications in which the temperature varies in a relatively wide range, for which averaged power density enhancement above 500% is attainable. (C) 2016 AIP Publishing LLC.

The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray showers detected by the Pierre Auger Observatory

In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10(17) and 10(19) eV and zenith angles up to 65 degrees. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.