Search results for "Energy engineering"
showing 10 items of 1099 documents
Modeling the Sequential Switching Shunt Series Regulator
2005
This letter characterizes, in terms of the bandwidth and limit cycle frequency of its constituent subsystems, the sequential switching shunt series regulator -S/sup 4/R, a high-efficiency, low-mass and volume power cell devised to power the next generation of regulated power buses in telecommunication spacecrafts. Transconductance power source modeling is used to obtain linear and nonlinear models. These are used to establish a design control strategy which involves the dynamic response in large load requirements or at the end of the satellite life. Simulations and experimental results are also given to demonstrate the validity of the model.
Interior permanent magnet synchronous motors: Impact of the variability of the parameters on their efficiency
2016
In the scientific literature, various authors presented different control strategies aimed to increase the efficiency of the interior permanent magnet synchronous motors. These strategies, starting from a well-known mathematical model of the dynamic behaviour of the motor, are able to reduce the power losses acting on the magnetizing component of the stator current. However, none of the proposed approaches takes into account that, varying the working conditions of the motor, also the values of the parameters, which have an impact on the power losses, can vary. In this paper, therefore, starting from an accurate measurement of the motor characteristics for various values of speed and load, w…
Optimized design of high power density EMI filters for power electronic converters
2016
Nowadays, power density of power converters and related EMI filters is gaining more and more attention. This severely impacts on the design constraints in several application domains. A conventional design of the EMI filter does not guarantee the selection of components/configuration leading to the best power density. For this reason, an optimized design procedure of discrete EMI filters in terms of power density is proposed in this paper. It is based on a previously developed rule-based design procedure, introducing here additional features to obtain a more effective optimization of EMI filter's power density. The proposed approach has been validated in terms of EMI filter's performance an…
Electrical characterization of CIGSSe photovoltaic modules
2017
This work describes the electrical characterization of CIG(S,Se) 2 sub-modules in order to compare the related performances with those obtained from traditional silicon photovoltaic modules. This characterization has been performed through means of a test bench, mainly composed by a solar simulator equipment, allowing the determination of the parameters of the prototypes under test at different irradiances and temperatures.
Experimental characterization of a wind generator prototype for sustainable small wind farms
2016
This paper presents the experimental characterization of a wind turbine prototype used for micro wind farms. The proposed prototype, whose advantages can be summarized in versatility of application, low noise and compactness, can generate 1 kW of rated power for a wind speed equal to 4 m/s. The tests here reported and carried out by means of an experimental test bench confirm that the prototype is well designed and adequate for the purpose of its application.
Optimization of a thermoelectric system for power generation realized by ‘‘hidden’’ components
2014
Abstract Today the utilization of renewable energy sources is very important to support the traditional ones, and also in order to reach the objectives fixed by the Kyoto Protocol. In this context, also well-known technologies related to the electric energy production, formerly not suitable – due to the poor technological level of the components or due to the high costs linked to the system efficiency – may now find a suitable collocation. Among these technologies, the thermoelectric effect may be very advantageous in some particular applications of small power. A power generation system utilizing this technology has been studied by the authors. This system utilizes the thermal difference b…
Guidelines for the design and implementation of the ARPCC control applied to grid-connected converters
2013
Abstract This paper presents implementation details of the adaptive robust predictive current control (ARPCC) applied to a grid-connected converter, such as feed-forward cancellation protocol, the selection of the observer gain and adaptive parameters or the sampling options, needed to get the best performance of this control. The feed-forward term cancellation permits to achieve a very low harmonic distortion in current waveforms when the voltage sensing circuits are well calibrated. A detailed gain adjustment protocol of the voltage sensing circuits is presented in this paper. Moreover, a control design procedure based on the observer gain L o boundaries and the adaptive parameters has be…
A New Measurement Method for the Detection of Harmonic Sources in Power Systems Based on the Approach of the IEEE Std. 1459–2000
2010
In this paper, a novel single-point strategy is proposed for the detection of the harmonic sources in power systems. The method is an improvement of a strategy previously proposed by the authors; it is developed from the IEEE Std 1459-2000 approach and it can be entirely implemented in the time domain, thus simplifying the measurement system. The effectiveness of the proposed method is evaluated by introducing simple decision-making rules and by taking the presence of the measurement transducers into account. Several simulations and experimental tests are presented, showing that the enhanced strategy is able to give an useful information on the detection of the dominant harmonic source upst…
Eletric vehicles impact using renewable energy
2015
In this moment, the principle topics for the modern world are the reduction of environmental pollution and the production of energy from renewable sources (for example photovoltaic system, wind farm, hydroelectric plants, etc.). This particular attention is determined by different reasons, in particular from the Kyoto Protocol, and from different problems as greenhouse effect, acid rain and climate change. The scope of this work is to study, for different years (1997-2013) in Italy, the production of electric energy from renewable and non-renewable. At a later stage, the attention will be on the consumption of the electric energy divided for different sectors. In particular, we study the po…
Assessing the gasification potential of five woodchips species by employing a lab-scale fixed-bed downdraft reactor
2015
Abstract This paper is aimed to assess the performance of air blown fixed-bed downdraft gasification of local lignocellulosic biomasses which in perspective of Southern Norway are both available and sustainable. Long rotation forest crops birch, oak and spruce, coupled with energy crops poplar and willow were used as feedstocks. The gasification conditions undertaken were widely varied in-terms of air (∼3.20–4.20 N m3/h) and fuel flow (∼1.70–2.10 kg/h) so that the corresponding equivalence ratio (ER) differed (0.19–0.80) and ultimately reflected to other operational parameters such as bed temperature (∼550–760 °C maximum), producer gas yield (∼1.50–2.30 N m3/kg, wet base), cold gas efficien…