Superconducting magnetic energy storage in power systems with renewable energy sources

Superconducting magnetic energy
storage in power systems with
renewable energy sources
Knut Erik Nielsen
Master of Science in Energy and Environment
June 2010
Norwegian University of Science and Technology
Department of Electric Power Engineering

LINK FULL THESIS
http://daim.idi.ntnu.no/masteroppgaver/005/5460/masteroppgave.pdf

Power Quality Improvement and Uninterruptible Power Supply Using a Power Conditioning System with Energy Storage Capability

 

Power Quality Improvement and Uninterruptible Power Supply Using a Power Conditioning System with Energy Storage Capability D. Casadei, Member, IEEE, G. Grandi, Member, G. Serra, Member IEEE, C. Rossi Department of Electrical Engineering, University of Bologna, via Risorgimento, 2 I-40136 Bologna ITALY, email: domenico.casadei@unibo.it, gabriele.grandi@unibo.it, claudio.rossi@unibo.it
Abstract-- A power conditioning system with energy storage capability is proposed as a viable solution for improving the quality and the reliability of the electric energy supply. Several tasks can be performed at the same time, such as reactive power compensation, current harmonic reduction, and smoothing of pulsating loads. Moreover, the power conditioning system can operate as an uninterruptible power supply during short time interruptions of the grid supply. The proposed system is a flexible structure that can be coupled to several energy storage devices like batteries, flywheels, supercapacitors, superconductive magnetic energy storage systems. In order to show the power conditioning system performance, experimental tests have been carried out using a flywheel as storage device. The effectiveness of the proposed control system has been successfully verified in several operating conditions of the grid supply and of the load.
LINK
http://www.die.ing.unibo.it/pers/grandi/papers/PTech2005.pdf

A Versatile Method for MOSFET Commutation Analysis in Switching Power Converter Design

A Versatile Method for MOSFET Commutation
Analysis in Switching Power Converter Design
Giulia Di Capua, Student Member, IEEE, and Nicola Femia, Senior Member, IEEE
Abstract—This paper discusses a novel method for the analysis
of MOSFET commutations and the investigation of related losses
and spike current issues in the switching power converter (SPC)
design. The synchronous rectification switching cell (SRSC) configuration
is considered for the investigation, which is used in the
high-frequency high-efficiency (H2 EF) SPC design. The proposed
method is aimed at providing an effective tool for quick feasibility
investigations and comparative evaluations among design solutions
using different MOSFET combinations for the design of
H2EF SPCs. The method allows us to use nonlinear models of
interelectrode MOSFET capacitances and adopts a novel numerical
technique specifically developed to solve the SRSC model ensuring
robust and fast simulations. Capacitive pulsating currents
circulating through the MOSFETs and the SPC during commutations
can be analyzed in detail by using the proposed method.
Different examples are discussed to show how MOSFETs characteristics
and operating conditions may affect switching losses,
because of the pulsing currents circulation through the SPC.

IMPACT OF INNOVATION TECHNOLOGY ON COMPLEX SYSTEMS: THE ELECTRIFIED RAILWAY SUPPLY SYSTEM

UNIVERSITÀ DEGLI STUDI DI NAPOLI “FEDERICO II”
POLO DELLE SCIENZE E DELLE TECNOLOGIE
FACOLTÀ DI INGEGNERIA
DIPARTIMENTO DI INGEGNERIA ELETTRICA
IMPACT OF INNOVATION TECHNOLOGY
ON COMPLEX SYSTEMS:
THE ELECTRIFIED RAILWAY SUPPLY SYSTEM
di
Daniela Proto
TESI DI DOTTORATO DI RICERCA IN INGEGNERIA ELETTRICA
XVII CICLO
(coordinatore: prof. Giovanni Miano)
LINK
http://www.fedoa.unina.it/405/1/Proto.pdf

EVALUATION OF AN EFFICIENCENT TRANSFORMER CORE DESIGN HEXATRANSFORMER

EVALUATION OF AN EFFICIENCENT TRANSFORMER
CORE DESIGN
Poonam Lutchman
A Dissertation submitted to the Faculty of Engineering and the Built
Environment, University of the Witwatersrand, in fulfilment of the requirements
of the degree of Master of Science in Engineering.

The hexa-transformer is a three-phase transformer with a symmetrical core. The
transformer core consists of nine rolls of laminated steel bands, with the core legs
having a cross sectional shape of a hexagon.
 Abstract

Distribution transformers have inherently high efficiencies of up to 99%, however they are in continuous operation and have a long lifespan, hence their power loss cost is still significant. A small efficiency improvement can lead to a considerable amount of energy savings over the lifetime of the transformer. Symmetric core design has the potential to improve transformer efficiency. The aim of this dissertation is to evaluate a relatively new symmetrical triangular core transformer for use in the Eskom Distribution network in South Africa. The transformer is called the hexa-transformer. A three phase 100 kVA hexa-transformer unit has been purchased from Hexaformer AB in Sweden. The unit has been routinely tested. A 50% no-load loss reduction has been achieved. The transformer was also opened and examined. The results indicated sound manufacturing quality. The economic analysis indicated a life cycle saving of R 2 727.41 per transformer over a 25 year period when compared to a conventional E-core transformer of the same rating. It is recommended that Eskom consider these units for future implementation in their Distribution network. LINKS THESIS
LINK1
http://wiredspace.wits.ac.za/handle/10539/12390
LINK2
http://www.mediafire.com/view/xw4x00cs9qyot73/Evaluation_of_an_efficient_transformer_core_design.pdf