Search results for "YBA"
showing 10 items of 116 documents
The new course of FITs mechanism for PV systems in Italy: novelties, strong points and criticalities
2011
The paper deals with the new course of the Feed-in Tariffs mechanism for photovoltaic systems that will start from January 1, 2011 in Italy with the actuation of the Government Decree DM 06/08/2010. After a short introduction on Feed-in Tariffs and Net-metering in Italy, the paper focuses the attention on an economical comparison between the incentives established by the Government Decree DM 19/02/07, ended on December 31, 2010 and those introduced by the DM 06/08/2010. The economical comparison is based on three indexes: the Pay Back Period, the Net Present Value and the Internal Rate of Return, characterizing the investments done for the realization of the photovoltaic systems. In particu…
The Road to Parnassus. Artist Strategies in Contemporary Art. Rise and Success of Glasgow artist Douglas Gordon and of the wider YBA generation
2015
How can one become a successful artist? Where should one start a career in the art world? What are useful strategies to achieve recognition in the art system? Such questions hoard in students' minds ever since entering art school and they probably chase every kind of art professional who is at an early career stage. “The Road to Parnassus” tries to understand what makes a good start in today's art world, who are influential players in the field and which strategies might apply. The swift career ascension of Glasgow artist Douglas Gordon – one of today's leading visual artists – and of the broader YBA generation that rose into worldwide prominence in the 1990s – Damien Hirst and Sarah Lucas …
Measurements of magnetic flux density in rotating machines : development of a calibrated and portable measurement system
2014
Masteroppgave i fornybar energi ENE 500 Universitetet i Agder 2014 Diagnostics of generator poles has traditionally been done by measuring the impedancein each pole and assume that the magnetic ux density is proportional to the impedance.With Hall-sensors it is possible to measure the actual magnetic ux density in each poledirectly. It is also possible to measure the ux density while the machine is runningwhich is not possible with impedance tests. In this project a complete system for makingmeasurements with Hall-sensors has been developed and tested on three generators. Twoof the generators were hydropower generators of 50 and 90 MVA. The measurementsystem is comprised of hall-sensors, po…
A DC current transformer for large bandwidth and high common-mode rejection
1999
A review of known magnetic-coupled current-sensing techniques is presented, Subsequently, a novel technique is introduced, based on a configuration discussed in a previous paper. The previous technique made use of a galvanomagnetic device (Hall effect sensor) to sense the magnetization of a current transformer core, so that the sum of the Hall voltage and the voltage across the secondary shunt resistor would yield a faithful copy of the input current. The technique described in this paper makes use of the same principle to obtain a high bandwidth (from DC to 1 MHz) and very high common-mode rejection current transformer, without the need for a Hall effect probe. This is achieved by subtract…
A novel solar-geothermal trigeneration system integrating water desalination: Design, dynamic simulation and economic assessment
2016
Abstract In this paper, an innovative solar-geothermal polygeneration system is investigated. The system supplies a small community with electricity, desalinated water and space heating and cooling through a district network. The hybrid multi-purpose plant, based on an Organic Rankine Cycle (ORC) supplied by medium-enthalpy geothermal energy and by solar energy; this latter is provided by Parabolic Trough Collectors (PTC). The geothermal brine is first used to drive the ORC loop, then to provide space heating at around 85÷90 °C (in the winter), or cooling (in the summer, by means of a single-effect absorption chiller). Finally, the geothermal brine drives a Multi-Effect Distillation (MED) s…
Life cycle assessment of a solar thermal collector: sensitivity analysis, energy and environmental balances
2005
Abstract Starting from the results of a life cycle assessment of solar thermal collector for sanitary warm water, an energy balance between the employed energy during the collector life cycle and the energy saved thanks to the collector use has been investigated. A sensitivity analysis for estimating the effects of the chosen methods and data on the outcome of the study was carried out. Uncertainties due to the eco-profile of input materials and the initial assumptions have been analysed. Since the study is concerned with a renewable energy system, attention has been focused on the energy indexes and in particular the “global energy consumption”. Following the principles of Kyoto Protocol, …
Life Cycle Assessment of Solar Technologies
2015
This chapter analyses the most common solar technologies and assesses their energy and environmental performance, based on a life cycle perspective. After a preliminary description of the main technologies, the chapter presents a review of studies on solar plants, as published in scientific journals in the past decade. Successively, the chapter assesses solar plants in comparison to other renewable and non-renewable based technologies, including a discussion of uncertainties and criticalities in the assessment
A new current-mode control for DC/DC converter
2005
Current-sensing is used widely in smart power chips, especially in DC/DC converter for voltage regulator modules (VRM), implemented with interleaved synchronous rectifier buck converters. The interleaved technique main difficulty is due to its current-sharing control between the several modules. Besides, if the used control technique is current-mode type, it is necessary create a ramp signal proportional to current on the inductor. In this paper, a lossless current-sensing method, solving the major disadvantages of the current-mode control and implementing a current-sharing technique, is proposed. This innovative technique is tested in a two-module interleaved buck converter.
A topology for multiple generation system with doubly fed induction machines and indirect matrix converter.
2008
In this paper, a new topology for a grid connected generation system based on two double fed induction generators is presented The scheme uses an indirect matrix converter consisting on an input rectifier, a three-to-two matrix converter which provides a DC voltage, and two voltage fed output converters. The input converter is connected to the grid and each of the output converters is connected to the rotor of the corresponding machine. The rotor currents of each generator are vector controlled and unity power factor operation at the indirect matrix converter input is considered. The duty cycles for the input converter are chosen in order to obtain maximum DC link voltage. The duty cycles f…
Stability improvement of isolated multiple-output DC/DC converter using coupled inductors
2016
Coupling output inductors is a very popular solution when designing a multiple-output DC/DC system. Space-borne circuits are one of the areas where a custom DC/DC converter design with coupled inductors could be preferred to have a detailed design of all variables. Output voltage regulation can be improved using coupled output inductors on a multiple-output DC/DC converter, and, as demonstrated in this paper, it provides an enhanced stability. This paper presents the small signal analysis of a push-pull converter with seven outputs having all its output inductors coupled together and compares it theoretically to the uncoupled version to demonstrate the stability improvement. The theoretical…