Estimation of Voltage and Current Distortions in the Power System Supplying the AC Arc Furnace

Published by Wiesław BROCIEK1, Robert WILANOWICZ2,Warsaw University of Technology (1) , Radom University of Technology (2) Abstract. The paper presents a circuit model of three phase arc arrangement, taking into account the nonlinearity of the arc appearing In the particular phases as well as the windings vector groups of a furnace transformer. This model wasContinue reading “Estimation of Voltage and Current Distortions in the Power System Supplying the AC Arc Furnace”

Electrical System

Published by Bureau of Energy Efficiency Syllabus Electrical system: Electricity billing, Electrical load management and maximum demand control, Power factor improvement and its benefit, Selection and location of capacitors, Performance assessment of PF capacitors, Distribution and transformer losses. 1.1 Introduction to Electric Power Supply Systems Electric power supply system in a country comprises of generatingContinue reading “Electrical System”

Energy Efficient Distribution Transformers

Published by Mariusz NAJGEBAUER, Krzysztof CHWASTEK, Jan SZCZYGŁOWSKI,Institute of Power Engineering, Częstochowa University of Technology Abstract. The paper presented the possibilities of improvement in properties of electric distribution transformers through the use of new soft magnetic materials, mainly amorphous alloys, as transformer cores. The properties of amorphous were compared to conventional electrical steel sheets. EconomicContinue reading “Energy Efficient Distribution Transformers”

High Voltage Test Transformers, Construction, Design and Their Application in HV Testing System

Published by Bogdan TUŁODZIECKI, Electric Apparatuses Factory Zwarpol Ltd. in Warsaw Abstract. In this article were described the most frequently used constructions of high voltage test transformers. There were presented defects, advantages and application of describing constructions. There were described how to design high voltage test transformers and what is important during their design. OnContinue reading “High Voltage Test Transformers, Construction, Design and Their Application in HV Testing System”

Distribution Transformers Protection Against High Frequency Switching Transients

Published by Dariusz SMUGAŁA1, Wojciech PIASECKI1, Magdalenia OSTROGORSKA1,Marek FLORKOWSKI1, Marek FULCZYK1, Paweł KŁYS2ABB Sp.z.o.o., Corporate Research Center, (1), ABB Sp.z.o.o., ABB Distribution Transformers, (2) Abstract. Distribution transformers protection method against high frequency transients generated during Vacuum Circuit Breaker (VCB) operations is presented in this paper. ATP/EMTP simulations of transients generated during the VCB operation andContinue reading “Distribution Transformers Protection Against High Frequency Switching Transients”

Steel Plant Transformer Operational Issues

Published by Tadeusz GLINKA1,2, Marek GLINKA2Politechnika Śląska w Gliwicach (1), BOBRME Komel (2) Abstract. Design of steel-plant furnace three-phase transformer (110 kV/(350 to 500) V, 50 kA) and its operating conditions are described in the paper. After three months of operation this transformer failed. Cause of failure, its course and damage to transformer winding areContinue reading “Steel Plant Transformer Operational Issues”

Common Power Quality Waveform Signatures

Published by Electrotek Concepts, Inc., PQSoft Case Study: Common Power Quality Waveform Signatures, Document ID: PQS0901, Date: October 15, 2009. Abstract: Power quality problems encompass a wide range of disturbances and conditions on utility and customer power systems. They include everything from very fast transients (microseconds) to long duration (hours) outages. Problems also include steady stateContinue reading “Common Power Quality Waveform Signatures”

Transformer Energizing and Dynamic Overvoltages

Published by Electrotek Concepts, Inc., PQSoft Case Study: Transformer Energizing and Dynamic Overvoltages, Document ID: PQS0709, Date: October 15, 2007. Abstract: Energizing power transformers results in inrush currents that are rich in harmonic components. The inrush current interacts with the system impedance vs. frequency characteristics to create a voltage waveform that can have significant harmonic componentsContinue reading “Transformer Energizing and Dynamic Overvoltages”

Modeling Ferroresonance in an Underground Distribution System

Published by Electrotek Concepts, Inc., PQSoft Case Study: Modeling Ferroresonance in an Underground Distribution System, Document ID: PQS0610, Date: July 1, 2006. Abstract: The objective of this case study is to provide an overview of ferroresonance phenomena, its modeling aspects, and practical experience in recognizing, avoiding, and solving the problem. In particular, it will present symptomsContinue reading “Modeling Ferroresonance in an Underground Distribution System”

Ferroresonance Analysis – 25kV Single 5-Legged Core Transformer

Published by Electrotek Concepts, Inc., PQSoft Case Study: Ferroresonance Analysis – 25kV Single 5-Legged Core Transformer, Document ID: PQS0318, Date: July 18, 2002. Abstract: Ferroresonance is a concern for medium voltage underground systems. As part of an evaluation of the design of a new 25kV underground system, the potential for ferroresonance was analyzed. Ferroresonance requires aContinue reading “Ferroresonance Analysis – 25kV Single 5-Legged Core Transformer”