An Introduction to Transformer Harmonic Current Derating Metrics

Published by Richard Lam, CHK Power Quality Pty Ltd. Website: http://www.chkpowerquality.com.au Abstract. Transformer harmonic current derating metrics; Harmonic Loss Factor, K-Factor, and Factor K are introduced, and used to calculate derating factors for dry and oil-filled type transformers. Introduction The introduction of Switched Mode Power Supplies (SMPS) in office equipment and LED lighting, Variable Frequency/SpeedContinue reading “An Introduction to Transformer Harmonic Current Derating Metrics”

Problems of the Current State of Power Quality and Proposals for their Solution

Published by Lidiya Kovernikova, Melentiev Energy Systems Institute of the Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russian Federation. Email: kovernikova@isem.irk.ru Abstract. The power quality in Russian electrical networks does not meet the requirements of regulatory documents. Big problems occur in all areas of people’s lives for this reason. Economic damage is oneContinue reading “Problems of the Current State of Power Quality and Proposals for their Solution”

Application of Electronic Load Circuit for Electrical Safety by using a Serial Mode Comparator

Published by Saktanong WONGCHAROEN1, Sansak DEEON1, Narong MUNGKUNG2, Pathumwan Institute of Technology, Thailand (1), King Mongkut’s University of Technology Thonburi, Thailand (2) Abstract. This research presented an electronic load circuit for electrical safety by using a serial mode comparator as a protection device against surges caused by electrical power lacking stability and quality. The applicationContinue reading “Application of Electronic Load Circuit for Electrical Safety by using a Serial Mode Comparator”

Impact of Harmonics on Power Quality and Losses in Power Distribution Systems

Published by M. Jawad Ghorbani, H. Mokhtari**, Dept. of CSEE, West Virginia University, Morgantown, WV, USA, ** Dept. of EE, Sharif University of Technology, Tehran, Iran. ABSTRACT – This paper investigates the harmonic distortion and losses in power distribution systems due to the dramatic increase of nonlinear loads. This paper tries to determine the amountContinue reading “Impact of Harmonics on Power Quality and Losses in Power Distribution Systems”

Comparison of Two Concepts for Modeling of Lightning Strike into Overhead Line

Published by Karol ANISEROWICZ, Politechnika Białostocka, Wydział ElektrycznyORCID: 0000-0001-8895-3954 Abstract. The paper presents a comparison of results of determining the lightning current flow in the shield wires of a high voltage line, using the model of lightning in the form of a lumped current generator and the antenna model, which takes the electromagnetic coupling intoContinue reading “Comparison of Two Concepts for Modeling of Lightning Strike into Overhead Line”

Impedance Correction Method of Distance Relay on High Voltage Transmission Line

Published by Samira SEGHIR, Tahar BOUTHIBA, Université des Sciences et de la Technologie d’Oran Mohamed BOUDIAF, USTO-MB, Faculté de Génie Electrique, Laboratoire LGEO, BP 1505 El M’Naouer, 31000 Oran, Alegria Abstract. A distance protection relay plays a major role in faults detection in the electric transmission line. The fault resistance has an effect on theContinue reading “Impedance Correction Method of Distance Relay on High Voltage Transmission Line”

Analysis of Thermal Field in 110 kV Cable Systems

Published by Janusz TYKOCKI1, Yong YUE2, Andrzej JORDAN3, The State College of Computer Science and Business Administration in Łomża (1), University of Bedfordshire (2), Visiting professor at University of Bedfordshire (UK), The State College of Computer Science and Business Administration in Łomża (3) Abstract. The paper presents the distribution of temperature field in high voltageContinue reading “Analysis of Thermal Field in 110 kV Cable Systems”

Effect of the Let-Through Energy of Overcurrent Protective Devices on the Temperature of Conductors during Short-Circuits

Published by 1. Stanislaw CZAPP, 2. Daniel KOWALAK, Gdańsk University of TechnologyORCID: 1. 0000-0002-1341-8276; 2. 0000-0001-9610-9884 Abstract. The scope of the verification of low-voltage systems covers the earth fault loop impedance measurement. This measurement is usually performed with the use of low-value current meters, which force a current many times lower than the one occurringContinue reading “Effect of the Let-Through Energy of Overcurrent Protective Devices on the Temperature of Conductors during Short-Circuits”

Influence of the Position of the Electrical Contact on the Size of the Temperature Distribution

Published by Dušan MEDVEĎ1, Ján ZBOJOVSKÝ2, Technical University of Košice. ORCID: 1. 0000-0002-8386-0000; 2. 0000-0003-4383-3996 Abstract. This paper deals with the investigation of temperature field distribution around the high-current electric contact. The analyses of temperature field were realised in simulation environment ANSYS and provide better understanding why the electrical contact position influences the heat dissipation.Continue reading “Influence of the Position of the Electrical Contact on the Size of the Temperature Distribution”

Diagnostics of Transformer Insulation by Frequency Domain Spectroscopy

Published by Miroslav GUTTEN, Daniel KORENCIAK, Peter BRNCAL, Viktor CEFER, University of Zilina, Slovakia Abstract. The paper deals with the diagnostics of insulation oil-paper in high-voltage transformers by frequency diagnostic spectroscopy. The first part of paper deals with the base information about diagnostics of power transformers. In this part are presented differently insulating methods, forContinue reading “Diagnostics of Transformer Insulation by Frequency Domain Spectroscopy”