1,720,952 research outputs found
Restructuring the existing medium voltage distribution grids using DC systems
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Bipolar DC grids on ships: possibilities and challenges
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
2021 Oregon seismic hazard database: purpose and methods
No full textReport. 2021 Oregon seismic hazard database : purpose and methods -- Plate 1. Perceived shaking and damage potential, probabilistic earthquake model -- Plate 2. Perceived shaking and damage potential, Cascadia subduction earthquake model -- Plate 3. Probability of damaging shaking.by Ian P. Madin, Jon J. Francyzk, John M. Bauer, and Carlie J.M. Azzopardi.Title from PDF cover (viewed on June 24, 2021).This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references (pages 44-47).Mode of access: Internet from the Oregon Government Publications Collection.Text in English
Optimal Battery Energy Storage System Sizing for Demand Charge Management in EV Fast Charging Stations
No full textThe high pulsating demand of fast charging stations (FCS) may cause monthly demand charges to account for a significant fraction of a station's electric bill. To reduce these costs, demand charge management can be applied to suppress peak power demands at FCSs, also using battery energy storage systems (BESS). This paper proposes a multi-objective approach for the optimal BESS and grid-tie sizing in FCS designs using genetic algorithms. With demand data from a FCS in the Netherlands, numerical studies are conducted in the Mosaik and Pymoo environments to assess the effectiveness of the proposed formulation.Accepted author manuscriptDC systems, Energy conversion & Storag
Comparison of system architecture and converter topology for a solar powered electric vehicle charging station
No full textAccepted Author ManuscriptOld - EWI-ESE-DC&S DC systems & StoragePhotovoltaic Materials and Device
Defining indigenous plants: some problematic species from Norfolk Island
No full textDefining indigenous species may at first appear straight forward; most botanical texts provide similar definitions. The consistent requirement of such definitions is the lack of human intervention in the occurrence of the species within the area under consideration. Islands around the world have been invaded by plant species brought to their shores by humans. They are also places where self-introduced species can be continually arriving, as they have done for millennia. Scrutiny of the situation on Norfolk Island (1200 km east of Australia) finds that the distinction between indigenous and introduced taxa is sometimes unclear. There is also inconsistency regarding the acceptance of self-introduced species as indigenous. This paper explores these issues and notes that they are more important than idle botanical curiosity, because control of introduced (weed) species is a major area of activity in managing protected natural areas
Revisiting the Partial Power Processing Concept: Case Study of a 5-kW 99.11% Efficient Flyback Converter-Based Battery Charger
No full textThis article proposes an analytical methodology to evaluate the performance of the main partial power processing (PPP) architectures in terms of the improvements in the system's conversion efficiency. This analysis considers the influence of the system's voltage gain, the auxiliary dc/dc converter's efficiency, and the possibility of bidirectional power flow. Herein, the key PPP architectures are, thus, modeled and benchmarked. The presented results attest to the series configuration as the most efficient PPP circuit solution, with no limits on the system voltage gain, contrary to the generalized results found in today's literature. To assess these results and the significance of the proposed analysis, a well-known, simple, and cost-effective flyback topology has been designed and tested for a series PPP circuit solution able to effectively interface a 5-kW battery energy storage system (BESS) to a 700-V dc grid. A relatively high power conversion efficiency and compact hardware are achieved due to the reduced size requirements on the input and output filtering stages. Above all, while explaining the PPP concept, this study shows that even converter circuits known for their low power efficiency can be used to derive highly efficient systems. A design approach is, thus, provided to facilitate the design of the presented PPP circuit, and measurements are, finally, carried out to compare the obtained results with the expected ones derived from the developed analytical models. Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Flexible Power Transfer Network
No full textThe flexible power transfer network is a conceptual transfer network for residential areas. The main advantage of the proposed concept is the increased safety and flexibility compared to currently used AC network. The core idea is to incorporate wireless power transfer into the network which leads to inherently safer and more flexible network compared to 50 Hz AC network. The networkmust be able to supply enough power to several loads without any means of communication between the source and the load side. Furthermore, with introduction of distributed energy sources (eg. PV), the network must also be able to operate several sources at one time. Themain challenge tackled in this thesis was a design of a controller that is able to control several sources simultaneously, independently and efficiently. The controller is the same for each source, which means that there is nomaster and no slave source and each source has the same priority. The solution provided in this thesis is based on the sliding mode control theory and the physics of series loaded resonant converter. The proposed controller is suitable to be used in applications like PV clusters, or other applications with distributed sources. The derivation of the controller proposed in this thesis starts with the energy-balance equation. However, it is realized that in order to control multiple sources with possibly different voltage levels it is important to utilize the reactive power. Therefore, the controller proposed emphasizes the power-balance equation. The dynamic stability of the power-balance controller is studied in the framework of sliding mode control theory.Electrical Engineering, Mathematics and Computer ScienceDC systems, Energy conversion & Storag
A Series Resonant Balancing Converter for Bipolar DC Grids on Ships
No full textBalancing converters are an integral part of a bipolar dc grid. In this paper, we propose a balancing converter based on a series resonant converter topology. The converter operates in the capacitive region with phase shift between the upper and lower H-bridges. The converter operation is analyzed and verified with LTSpice simulation. A prototype is developed to verify the operation.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
Cases of Soft Switching in a Series Resonant Balancing Converter for Bipolar DC Grids
No full textBalancing converters are an integral part of a bipolar dc grid. Resonant converter topologies are interesting for power electronics engineers due to their soft switching capabilities. A series resonant converter topology is promising as a balancing converter in a bipolar dc grid. The series resonant converter is usually a non-inverting topology. However, in the balancing converter application, the converter is used as an inverting type, like a buck-boost converter topology. In this paper, the soft switching capabilities of this converter are shown and analyzed for four distinct converter modulation schemes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.DC systems, Energy conversion & Storag
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