Magazine Volume 2 Issue 1

Experience with Regulation of Network Quality in Italy, the UK and The Netherlands

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Virendra Ajodhia, Konstantin Petrov, Gian Carlo Scarsi, Bart Franken

Both theory and practice suggest that incentive price regulation, without additional quality measures, eventually leads to quality degradation: the strong cost reduction incentives (driven by the profit incentive) have the perverse effect of inducing sub-standard quality levels. Thus, under economic regulation models using incentive schemes, quality regulation becomes imperative.

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Classification Methodologies for Power Quality

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J.F.G. Cobben, Jasper F.L. van Casteren

Ongoing processes of restructuring and regulation are taking place in the electricity sectors of all European countries. These processes are targeting towards more transparent competition in the generation and retail of electrical energy. The physical transmission and distribution of electricity is thereby considered to be a natural monopoly that is to be unbundled from generation and retail and which needs to be regulated. New performance based regulatory frameworks are discussed, such as price caps or revenue caps.

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Effect of PQ-Monitor Connection on Voltage Dip Indices: PN vs PP Voltages

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Roberto Chouhy Leborgne, Gabriel Olgiun, Jose M. Carvalho Filho, Math H.J. Bollen

This work addresses the influence of the PQ-monitor connection on the estimation of voltage dip site and system indices. Voltage dip indices are estimated for a set of events obtained from simulation and measurement of voltage dips. The simulated dips are obtained applying the method of fault positions on a large transmission network and the measured dips come from a one-year survey realized on three buses of a sub-transmission and distribution network.

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Low Voltage Fault Detection and Localisation Using the TOPAS 1000 Disturbance Recorders

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Stephanie L. Horton, Nico G. van Luijk

During the past 20 years an increasingly competitive power industry has recognised the importance of addressing the issue of power quality. Many companies now take an active roll in addressing the problems associated with power quality. They are investing in the research and development of equipment to overcome power dips, surges and interruptions, and offering the customer a wide and varied choice of solutions and services to their power quality needs.

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Analysis of a TSC Failure in a Steel Mill Industry

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Hossein Mokhtari, Abolfazl Zebardast, Mostafa Parniani

This paper presents the results of a thorough analysis of failure of TSC modules in a steel mill plant. The TSCs are used to reduce the flicker level caused by the arc furnace loads used in the plant. The plant is modeled and Harmonic analysis is carried out. Statistical analysis is performed and the results are compared with IEEE 18 standard limits. The system is analyzed and the resonance modes are extracted. Site measurements are carried out, and the results, which verify those obtained by the simulations are also presented.

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New Fault Detection Techniques for Induction Motors

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Jordi Cusido, Javier Rosero, Emiliano Aldabas, Juan Antonio Ortega, Luis Romeral

Double frequency tests are used for evaluating stator windings analyzing the temperature. Likewise, signal injection on induction machines is a well-known technique on sensorless motor control fields to find out the rotor’s position. Motor Current Signature Analysis (MCSA) is the most widely used method for identifying faults in Induction Motors. MCSA focuses its efforts on the spectral analysis of stator current.

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Conducted EMI Propagation in Inverter-Fed AC Motor

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Jarosław Łuszcz, Krzysztof Iwan

Conducted EMI generated by an inverter-fed induction motor drive systems with the pulse with modulation (PWM) are one of the most difficult current technical problem which limits power electronics drive’s evolution. The conducted and radiated emission of PWM drives is essentially related also to the electric behaviour of the frequency converter’s load which is AC motor and motor cable. Detailed analysis of the impedance characteristics of the converters load (motor and cable) is fundamental to interpret the common and differential mode of emission spectra of the converter.

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Impact of Multi-Cycle Symmetrical Control on Power System

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Roger Bergeron

Multi-Cycle symmetrical control (MCSC) for application above 1.2 kW fails compliance tests once IEC 61000-4-7 edition 2 introduced a new assessment method which groups inter-harmonic into the harmonic levels. MCSC-driven apparatus up to 3 kW may succeed the compliance test if IEC 61000-4-7 neglects interharmonic components at frequencies below the second harmonic order. Upon the power level, MCSC-driven apparatus could disturb the ripple-control system needed for communication.

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Harmonic Analyses and Mitigation in Large Industrial Steel Plants - A Case Study

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Walter T.J. Hulshorst, Aart L. Keet, Johan H.R. Enslin

At its plant in the Dutch town of IJmuiden, steel-producer Corus has its own electricity network. For steel making electrical energy is needed, specially for the mill section, due to older techniques these installations produces more voltage distortion on the Corus network. This can cause equipment outages, and thus halt production. This paper presents an innovative solution to these problems, thereby limiting production losses and system mal operation and without exceeding of harmonic limits at the connection to the grid- operators network.

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Predicting Harmonics by Simulations - A Case Study for High Power Adjustable Speed Drives

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Lucian Asiminoaei, Steffan Hansen, Frede Blaabjerg

This paper describes the measurements and simulations of harmonics from adjustable speed drives in a 1.2 MVA Heat Power Station application. The simulations are done in two ways, one by Pspice circuit simulator and the other by a custom developed harmonic toolbox. It is proven that Pspice is more flexible and offers a better precision in estimation, but in turn the developed toolbox is more practical and relatively accurate for many useful evaluations. Both harmonic simulations are validated by real measurements for the given plant, within an error of 5 % between the measured and the simulated data.

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