18,408 research outputs found
Power quality and electromagnetic compatibility: special report, session 2
The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems.
Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages).
The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks:
Block 1: Electric and Magnetic Fields, EMC, Earthing systems
Block 2: Harmonics
Block 3: Voltage Variation
Block 4: Power Quality Monitoring
Two Round Tables will be organised:
- Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13)
- Reliability Benchmarking - why we should do it? What should be done in future? (RT 15
Multilevel Converters: An Enabling Technology for High-Power Applications
| Multilevel converters are considered today as the
state-of-the-art power-conversion systems for high-power and
power-quality demanding applications. This paper presents a
tutorial on this technology, covering the operating principle and
the different power circuit topologies, modulation methods,
technical issues and industry applications. Special attention is
given to established technology already found in industry with
more in-depth and self-contained information, while recent
advances and state-of-the-art contributions are addressed with
useful references. This paper serves as an introduction to the
subject for the not-familiarized reader, as well as an update or
reference for academics and practicing engineers working in
the field of industrial and power electronics.Ministerio de Ciencia y Tecnología DPI2001-3089Ministerio de Eduación y Ciencia d TEC2006-0386
Power Flow Modelling of Dynamic Systems - Introduction to Modern Teaching Tools
As tools for dynamic system modelling both conventional methods such as
transfer function or state space representation and modern power flow based
methods are available. The latter methods do not depend on energy domain, are
able to preserve physical system structures, visualize power conversion or
coupling or split, identify power losses or storage, run on conventional
software and emphasize the relevance of energy as basic principle of known
physical domains. Nevertheless common control structures as well as analysis
and design tools may still be applied. Furthermore the generalization of power
flow methods as pseudo-power flow provides with a universal tool for any
dynamic modelling. The phenomenon of power flow constitutes an up to date
education methodology. Thus the paper summarizes fundamentals of selected power
flow oriented modelling methods, presents a Bond Graph block library for
teaching power oriented modelling as compact menu-driven freeware, introduces
selected examples and discusses special features.Comment: 12 pages, 9 figures, 4 table
Two-stage optimization method for efficient power converter design including light load operation
Power converter efficiency is always a hot topic for switch mode power supplies. Nowadays, high efficiency is required over a wide load range, e.g., 20%, 50% and 100% load. Computer-aided design optimization is developed in this research work, to optimize off-line power converter efficiency from light load to full load. A two-stage optimization method to optimize power converter
efficiency from light load to full load is proposed. The optimization procedure first breaks the converter design variables into many switching frequency loops. In each fixed switching frequency loop, the optimal designs for 20%, 50% and 100% load are derived separately in the first stage, and an objective function using the optimization results in the first stage is formed in the second stage to consider optimizing efficiency at 20%, 50% and 100% load. Component efficiency models are also established to serve as the objective functions of optimizations. Prototypes 400V to 12V/25A 300W two-FET forward converters
are built to verify the optimization results
Bond Graph Based Stability Analysis of a Railway Traction System
This paper emphasises the interest of the Bond Graph approach for analysis and system design of heterogeneous and multi-field devices. In particular, the local stability analysis of non linear systems can be directly derived from the linearised Causal Bond Graph. This method is applied to a typical electrical engineering system: a railway traction device involving electromechanical couplings. Validity, usefulness and originality of this approach are displaye
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An Assessment of PIER Electric Grid Research 2003-2014 White Paper
This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of California’s California Institute for Energy and the Environment, from 2003-2014
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