Section 4: System Voltage Considerations

Published by Bill Brown, P.E., Square D Engineering Services. Basic Principles The selection of system voltages is crucial to successful power system design. Reference [1] lists the standard voltages for the United States and their ranges. The nominal voltages from [1] are given in table 4-1. As can be seen, ANSI C84.1-1989 divides system voltagesContinue reading “Section 4: System Voltage Considerations”

FLEX-CORE® Glossary of Terms

Published by FLEX-CORE®, Div. Morlan & Associates, Inc. Current Transformers Usually rated on a basis of 5 amperes secondary current and used to reduce primary current to usable levels for transformer-rated meters or transducers and to insulate and isolate them from high voltage circuits. Current Transformer Ratio Ratio of primary to secondary current. For aContinue reading “FLEX-CORE® Glossary of Terms”

Understanding Current and Voltage Harmonics

Published by L&T Electrical & Automation, Website: Source: Current and voltage harmonics are often used interchangeably. At most places, only harmonics is quoted and whether the values pertain to current or voltage is not mentioned. The differentiation can be done on the basis of their origin. Understanding Total Harmonic Distortion The current andContinue reading “Understanding Current and Voltage Harmonics”

Power Quality Measurements in All Voltage Levels of the Utilities up to 150 kHz – Is it Possible?

Published by Roland Buerger (MBS AG), Business Development/R & D, MBS AG, Sulzbach-Laufen (Germany), Email: Bernhard Grasel (NEO MESSTECHNIK), Sales Manager, NEO Messtechnik, Zoebern (Austria), Email: A reliable energy supply has meanwhile become an important location factor for many companies. While power failures and voltage fluctuations were among the most important parameters ofContinue reading “Power Quality Measurements in All Voltage Levels of the Utilities up to 150 kHz – Is it Possible?”

Technical Design Specifications and Criteria for Integrating PV Systems into Distribution Networks in Egypt

Published by Omar H. Abdalla, Fellow Egyptian Society of Engineers, Life Senior Member IEEE. Prof. O. H. Abdalla is with the Department of Electrical Power and Machines Engineering, Faculty of Engineering, 1 Sherief Street, P.O. Technology, P.C. 11792, Helwan, Cairo, Egypt. (e-mail: Conference Paper: Keynote Lecture (KL-REN-5), International Conference on New Energy and EnvironmentalContinue reading “Technical Design Specifications and Criteria for Integrating PV Systems into Distribution Networks in Egypt”

Bridging the Gap Between Signal and Power

Assessing Power System Quality using Signal Processing Techniques Published by Math H.J. Bollen1, Irene Y.H. Gu2, Surya Santoso3, Mark F. McGranaghan4, Peter A. Crossley5, Moisés V. Ribeiro6, and Paulo F. Ribeiro7 Source: IEEE Signal Magazine, 2009 Signal processing has been used in many different applications, including electric power systems. This is an important category, sinceContinue reading “Bridging the Gap Between Signal and Power”

Low Voltage Distribution Board Safety

March, 2007 Published by Terry Chandler Director of Engineering, Power Quality Thailand LTD/Power Quality Inc., USA. Emails:, Accidental Death is REAL!! Electrical Shock Fatalities in the USA Electric shocks are responsible for about 1,000 deaths in the United States each year, or about 1% of all accidental deaths. Electric shocks cause death in 3-15% of cases.Continue reading “Low Voltage Distribution Board Safety”

Part 2: AC Power Distribution Systems & Standards

Published by Nikola Zlatanov* Voltage Classifications ANSI and IEEE® standards define various voltage classifications for single-phase and three-phase systems. The terminology used divides voltage classes into: Low voltage Medium voltage High voltage Extra-high voltage Ultra-high voltage Table 1.1-1 presents the nominal system ese classifications. Voltages and Voltage Ranges (From IEEE Standard 141-1993) BIL—Basic Impulse LevelsContinue reading “Part 2: AC Power Distribution Systems & Standards”

Overview of IEEE STD 1564-2014 Guide for Voltage Sag Indices

Published by Daniel Sabin, Electrotek Concepts , USA and Math Bollen, Luleå University of Technology, Sweden Emails: & Published in 23rd International Conference on Electricity Distribution, Lyon, 15th-18th June, 2015 ABSTRACT IEEE Std 1564-2014 Guide for Voltage Sag Indices is a new standard that identifies appropriate voltage sag indices and characteristics of electricalContinue reading “Overview of IEEE STD 1564-2014 Guide for Voltage Sag Indices”

Voltage Tolerance Boundary

Published by Pacific Gas and Electric Company (PG&E), January 1999. The only national standard for utilization voltage regulation is ANSI C84.1. Its title is American National Standard for Electric Power Systems and Equipment – Voltage Ratings (60 Hertz). The first version in 1954 was a combination of two standards, one from the Edison Electric InstituteContinue reading “Voltage Tolerance Boundary”