Industrial Grids with Frequency Inverters and Localization of the Earth Fault

Published by Tomáš SNIEGOŇ, Jiří GURECKY, Department of Electrical Power Engineering, VŠB – TU Ostrava Abstract. This article focuses on industrial grids with frequency inverters and evaluation of the earth fault and its localization. In the first part the system of localization of the earth fault, industrial grids with frequency inverters and typical application inContinue reading “Industrial Grids with Frequency Inverters and Localization of the Earth Fault”

The Influence of Earth Thermal Conductivity on Temperature Profile of 110 kV Electric Power Cable System

Published by Janusz TYKOCKI, The State College of Computer Science and Business Administration in Lomza Abstract. The paper presents the conductivity of the ground effect on the distribution of temperature field in three-phase high-voltage cables, 64/110 kV, depending on the depth of their arrangement in the ground. The simulation uses the finite element method FEM.Continue reading “The Influence of Earth Thermal Conductivity on Temperature Profile of 110 kV Electric Power Cable System”

Temporary Overvoltage and Grounding Transformer Analysis

Published by Electrotek Concepts, Inc., PQSoft Case Study: Temporary Overvoltage and Grounding Transformer Analysis, Document ID: PQS1203, Date: January 25, 2012. Abstract: This case study presents the results for a wind plant temporary overvoltage (TOV) and grounding transformer transient analysis. The case study investigated the potential for excessive temporary overvoltages during single-phase faults on a 34.5Continue reading “Temporary Overvoltage and Grounding Transformer Analysis”

Hazardous Step Voltage Nearby Pole Exited by High Voltage Surge

Published by Jarosław WIATER, Politechnika Białostocka, Wydział Elektryczny, Katedra Telekomunikacji i Aparatury Elektronicznej Abstract. This paper presents a ground potential rise (GPR) and voltage difference measurement results. Measurements were made for a model of a pole installed in homogeneous ground. The test stand was built in high voltage lab. It allows safe high voltage testingContinue reading “Hazardous Step Voltage Nearby Pole Exited by High Voltage Surge”

Lightning Currents in Low-Voltage Power Systems

Published by Andrzej SOWA, Bialystok University of Technology, Faculty of Electrical Engineering Abstract: Correctness estimation of lightning protection solutions require definition of lightning current distribution in conductive installations entering the structure during direct strike to lightning protection system of this structure. It concerns particularly this part of lightning current, which flows in electric installation. InformationContinue reading “Lightning Currents in Low-Voltage Power Systems”

Step Voltage Nearby Tree for Surge Current Excitation

Published by Jarosław WIATER, Białystok University of Technology Abstract. Step voltage situation arise when it is possible for a person to make simultaneous contact with a part of an electrical system which is not live under normal conditions but has become live due to the passage of current for example lightning strike one. The purposeContinue reading “Step Voltage Nearby Tree for Surge Current Excitation”

The Effect of PWM Frequency on the Effectiveness of Protection Against Electric Shock using Residual Current Devices

Published by Stanisław CZAPP , Gdańsk University of Technology, Faculty of Electrical and Control Engineering Abstract. In the paper spectral analysis of the distorted earth fault currents in circuits with variable speed drives is performed. Effectiveness of protection against electric shock using residual current devices in circuits with variable speed drives for various PWM frequenciesContinue reading “The Effect of PWM Frequency on the Effectiveness of Protection Against Electric Shock using Residual Current Devices”

Understanding Power Quality Concepts

Published by CEA Technologies Inc. (CEATI), POWER QUALITY Energy Efficiency Reference Guide, Chapter 2 – Understanding Power Quality Concepts. 2.1 The Electrical Distribution System One of the keys to understanding power quality is to understand how electrical power arrives at the socket, and why distribution is such a critical issue. Electrical power is derived fromContinue reading “Understanding Power Quality Concepts”

High Neutral-to-Ground Voltages

Published by Electrotek Concepts, Inc., PQSoft Case Study: PQ Investigation at a Battery Facility, Document ID: PQS0401, Date: March 30, 2004. Abstract: An office complex was experiencing continual operational problems with some of their electronic equipment not protected by power conditioning equipment. The equipment would periodically exhibit strange behavior. An infrared heat detector was used toContinue reading “High Neutral-to-Ground Voltages”

PQ Investigation at a Battery Facility

Published by Electrotek Concepts, Inc., PQSoft Case Study: PQ Investigation at a Battery Facility, Document ID: PQS0402, Date: March 30, 2004. Abstract: This case study presents the results of a power quality investigation at a battery manufacturing facility. The facility had been experiencing a high rate of motor failures and was experiencing problems with its computerContinue reading “PQ Investigation at a Battery Facility”