Search results for "Energy engineering"
showing 10 items of 1099 documents
Electrodeposited nickel–zinc alloy nanostructured electrodes for alkaline electrolyzer
2022
Abstract Over the last decade, as a consequence of the global decarbonization process, the interest towards green hydrogen production has drastically increased. In particular a substantial research effort has focused on the efficient and affordable production of carbon-free hydrogen production processes. In this context, the development of more efficient electrolyzers with low-cost electrode/electrocatalyst materials can play a key role. This work, investigates the fabrication of electrodes of nickel-zinc alloys with nanowires morphology cathode for alkaline electrolyzers. Electrodes are obtained by the simple method of template electrosynthesis that is also inexpensive and easily scalable.…
Design and performance evaluation of a high power density EMI filter for PWM inverter-fed induction motor drives
2015
This paper presents the design of an electromagnetic interference (EMI) filter for a low voltage high current induction motor drives supplied by DC power grids, such as those used in several vehicle applications. In order to effectively design the EMI filter a suitable Common Mode/Differential Mode (CM/DM) separation technique has been used. In consideration of the high operating currents, a software based separation technique using time domain measurements has been applied. The proposed technique allows the CM and DM sections of the EMI filter to be properly selected in a more economical way, i.e. without the need of dedicated hardware or costly radio frequency (RF) instrumentation. The de…
Power dispatching techniques as a finite state machine for a standalone photovoltaic system with a hybrid energy storage
2020
Standalone photovoltaic system (SPVS) is usually embedded with an energy storage unit to overcome the intermittency of photovoltaic (PV) generation as well as to address load variations in off-grid operation. In SPVS energy systems, batteries can serve as the long term energy storage and contributing to the large portion of the energy demand but to overcome the load intermittency, it necessitates a fast response energy storage embedded with the battery as a hybrid energy storage (HES) for dynamic loads (e.g., Electric Vehicle loads, emergency power management). In this work, Lead-Acid (LA) battery and supper capacitor (SC) array are used as the HES. HES helps not only in increasing more uti…
Green Data Centres integration in smart grids: New frontiers for ancillary service provision
2017
Abstract The paper presents a study, conceived within the GEYSER FP7 co-funded European research project, on the ancillary services that Green Data Centres (GDCs) can provide, focusing, in particular, on spinning reserve. More in detail, the main contribution of the paper is to show how GDCs can be involved in the secondary frequency regulation process of a smart distribution grid, for contrasting the disturbing effects of unexpected variation of the energy production. With this aim, a real data centre, owned by Engineering S.p.A., is simulated as connected to the Medium Voltage IEEE 14-bus test grid where some RES-based generators are supposed to exist. Simulations are carried out in order…
A distributed minimum losses optimal power flow for islanded microgrids
2017
Abstract In this work, the minimum losses optimal power dispatch problem for islanded microgrids with distributed energy resources (DER) is solved by means of a distributed heuristic approach. Optimal power management is performed almost in real time, with a predefined schedule, i.e. every 5 min, and the solution is applied to generators when the current operating solution violates voltage or current constraints or when the current configuration produces too large power losses. The operating point of both inverter-interfaced generation units as well as rotating production systems can be modified simply using local information. The latter are voltage measurements and power injections or load…
A review of fuel cell based hybrid power supply architectures and algorithms for household appliances
2014
Abstract Nowadays, renewable power system solutions are widely investigated for residential applications. Grid-connected systems including energy storage elements are designed. Advanced research is actually focused on improving the reliability and energy density of renewable systems reducing the whole utility cost. Source and load modeling, power architectures and algorithms are only a few topics to be addressed. Designers have to carefully deal with each subtopic prior to design efficient renewable energy systems. In the literature, each topic is separately discussed and the lack of a unique reference guide is clear to power electronics designers. In this paper, each design step including …
Ev charging station at university campus
2017
This paper faces the technical and economic challenges related to the design of a green recharge area for electric vehicles at the Campus of Palermo, Italy, with the aim of reduce both costs and pollution connected to the charging process. Based on the behaviour of the student population, the electrical load is identified and two possible solutions are evaluated to manage the peak load: an orientation of the panels increasing the power at defined time and the use of a storage system. The main strength and weakness points of two systems are investigated by taking into account the Levelized Cost of Energy (LCOE), which reaches 75.3 â¬/MWh for the orientation of panel and 103 â¬/MWh for stor…
Hydrogen and methane yields of untreated, water-extracted and acid (HCl) treated maize in one- and two-stage batch assays
2011
Abstract In the present study, two-stage H 2 and CH 4 production was compared with one-stage CH 4 production from maize subjected to water extraction and acid (HCl) treatment. In addition, the effect of duration (2 and 14 days) of the first-stage H 2 process on the H 2 yields and subsequent CH 4 yields from the second-stage was also investigated. Results showed that the average H 2 yields from untreated maize were 5.6 and 9.9 ml/g volatile solids added (VS added ) after 2 and 14 days, respectively. On the other hand, H 2 yields from water-extracted and HCl-treated maize were 18.0 and 20.5 ml/gVS added (14 d), respectively. On comparison to one-stage CH 4 assays, the average increase in CH 4…
Comparison between Different Dynamic Reconfigurations of Electrical Connections for partially shaded PV Modules
2018
This paper presents an economical investigation on the benefits related to the employment of reconfiguration systems for photovoltaic plants. More in detail, different structures of reconfigurators are proposed and, in order to evaluate the economical convenience on their installation, the Net Present Value is used as a validation element. Significant results are carried out from the proposed analysis.
Two-phase flow of liquid–liquid mixture in the range of the water droplet pattern
2002
Abstract Phenomena accompanying flow of water–oil mixture during droplet flow of water in oil have been described. Aims used in the determination of characteristic parameters in two-phase liquid–liquid flow have been presented. The method for calculating the equivalent viscosity and pressure drop during flow of liquid–liquid mixture in the range of the water droplet pattern has been given.