Spring 2009 Issue
The protection of distribution systems in the last century (and in many places still today) was very simple and diverse in different parts of the world. I remember when I started my career as a protection engineer many years ago that we used on some distribution feeders three electromechanical relays - two for phase overcurrent protection and one for ground. The logic, as explained to me a... More


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Industry News

Advanced Transformer Protection and Control

AREVA Substation Automation Solutions introduces the MiCOM P64X which preserves service life, and offers fast protection for transformer faults. Hosted on an advanced IED platform, the P64X incorporates differential, REF, thermal and overfluxing protection, plus backup protection for uncleared external faults. Model variants cover two & three winding transformers (including autotransformers), ... More

Arc-Flash Detection

New Relay from SEL The SEL-751A Feeder Protection Relay from Schweitzer Engineering Laboratories is now available with arc-flash detection (AFD) capability, providing automatic protection against dangerous arc-flash events in metal-clad switchgear. AFD interrupts power to the arc flash before it can cause significant damage or personal injury. Fiber-optic light sensors in the SEL-751A ... More

Basler Plug-n-Play Relay add Arc Flash Detection

Basler Electric, the Retrofit Relay Experts have supplied several utilities and industrials users BE1-50/51B-Plug-n-Play Single-Phase Overcurrent relays over the years. The relays are direct replacements for electromechanical CO or IAC relays. They fit into existing cases, require no panel modifications or re-wiring. Panels can literally be upgraded in hours vs. days or weeks. Basler h... More

i-PCGRID Workshop

The annual i-PCGRID (Innovations in Protection and Control for Greater Reliability Infrastructure Development) workshop was held on March 18-20, 2009, in San Francisco, California. Some of the power industry's foremost authorities joined leading academic researchers, prominent government experts and regulatory practitioners from around the world at this sixth annual event. The wo... More

Innovative NCT Network Computing Terminal

The Toshiba Network Computing Terminal is a device for monitoring electric power systems. Utilizing an embedded real-time OS and Java Virtual Machine together with web-server and mobile agent technologies, the NCT provides Synchrophasor functionality and instantaneous measurands. Setting and maintenance is achieved using a common browser. Many application are in practical use; Wide area mea... More

Multilin 350 Feeder Protection System

Intuitive & Intelligent Feeder Protection System with Advanced Communications and Diagnostics The Multilin 350 protection relay provides the utility power distribution industry with a technologically advanced, easy to use, and intuitive overcurrent (50/51) protection relay. The Multilin 350 performs primary circuit protection of medium voltage distribution feeders. The robust Multilin 350... More

Recloser & Sectionalizer Test Cable Solutions

OMICRON electronics has developed test cables to simplify testing of distribution reclosers and sectionalizers, including their controllers and switches, for use with the CMC 356/256 test sets. Each OMICRON test cable is designed with all components necessary to make an end-to-end direct connection between the test device and the CMC to allow testing of all functionality that the manufa... More

TM 1703 Distributed I/O Module of the TG5700 RTU

Siemens Energy is announcing the introduction of the TM 1703 Distributed I/O Module to our TG5700 RTU product line. The TM 1703 improves the distributed capabilities of the TG5700 RTU by adding local IED ports, local PLC programmability and new electrical interfaces, like direct Pt-100 Ohm temperature probe inputs. Applications for the TG5700 RTU with TM 1703 I/O extend to Condition Based Mon... More

Traveling Wave fault location

REASON International is introducing its line for Traveling Wave-based fault location in the North American market. Wave detection error due to misinterpretation of the fault is a major kind of error in many types of traveling wave-based equipment on the market. REASON has developed a very reliable method in order to record the correct traveling wave. The approach is to acquire the traveling wave... More

Technology News

'Magic' Lights - expected to slash household electricity use

A new way of making LEDs could see household lighting bills reduced by up to 75% in five years time, thanks to research at Cambridge University, UK. The new LEDs use Gallium Nitride (GaN), a man-made semiconductor that emits a brilliant bright light but uses very little electricity. Until now however, high production costs have made GaN lighting too expensive for widespread use in homes a... More

Shock- absorber

Power from bumps in the road A team of MIT undergraduate students has invented a shock absorber that generates electricity from small bumps in the road, while at the same time it smoothes the ride more effectively than conventional shocks. Hybrid vehicles use some of the wasted energy during breaking, so the team looked for additional places in a vehicle where energy is wasted. The suspe... More

ZigBee communications

The increasing interest around the world in development of "smart grids" requires the acceptance of communications standards that are designed specifically for low power, low data rate networks. The protocols need to be secure, robust, and resistant to outside RF interference in order to be used for industrial and home automation networks. IEEE 802.15.4 was designed to address the need for ... More

Cover Story

Using advanced distribution protection functions can significantly reduce fault clearing times

The electric power industry is going through significant changes due to the increased requirements for improved quality of power supplied by the utility in order to avoid costly interruptions of manufacturing or other processes caused by voltage sags, swells or unbalanced conditions when a short circuit fault occurs in the distribution system. The improvement of power quality during s... More

IEC 61850 Update

IEC 61850 and condition monitoring

How can I perform the different tests of a substation automation system (SAS) in the future? Does IEC 61850 help me or does it make life more difficult? What if I have a process bus connecting the breakers and sensors with the protection relay? This is one of the topics we try to clarify with Edition 2 of the standard. Already Edition 1 had many features intended to support testing, like ... More

Distribution Single-Phase Tripping and Reclosing

Distribution Single-Phase Tripping and Reclosing

Overcoming Obstacles An increased focus on service reliability causes many utilities to look at their distribution protection practices . Although modern power distribution systems use single-phase protective devices, utilities have been reluctant to consider singlepole tripping on the main three-phase line for a variety of reasons, including a desire to protect three-phase loads, difficulty... More

A Guide for Young Protective Relay Engineers

A Guide for Young Protective Relay Engineers

"Science is systemized knowledge. Art is knowledge made efficient by skill". Webster's Collegiate Dictionary, Fifth Edition, G. and C. Merriam Co., Springfield, Mass., 1942 Following my electrical engineering education at the Georgia Institute of Technology in Atlanta, GA I was in search of a career that was not only challenging but also stimulating and self-satisfying. I was f... More

NERC System Protection Initiative

NERC System Protection Initiative

Misoperation of system protection and control systems have been a leading cause of bulk power system disturbances in North America for a number of years, causing nearly 45% of category two and higher disturbances in 2007. As part of its mission to "ensure the reliability of the bulk power system in North America," NERC is launching a comprehensive initiative designed to coordinate many val... More

Cold Load Pickup IEEE PSRC

Cold Load Pickup IEEE PSRC

This article is a summary of a report to the Line Protection Subcommittee of the Power System Relay Committee of the IEEE Power & Energy Society, prepared by working group D1. It describes cold load pickup and inrush problems as they affect protective relaying Applications on distribution feeder circuits and provides guidance for protective system applications. The complete report can be d... More

Main 1 and Main 2 Protection - Same or Different?

Main 1 and Main 2 Protection - Same or Different?

Redundant functionally equivalent protection systems (FEPS, sometimes known as main 1 and main 2) are usually applied for transmission line protection. What are the relative advantages and disadvantages of using different types of systems for FEPS? This article discusses this question. Most utilities provide redundant FEPS on the Bulk electric System to maximize the dependability o... More

Legal Issue

Possible Legal Concerns

Author: Iana A. Apostolova, Esq. In the last article we began to address the issue of potential civil liability that may befall an electric utility or a particular substation. We introduced official sounding terms like torts and tortfeasors and began to differentiate between the possible intentional versus negligent torts for which consumers may attempt to sue a power company, and in tur... More

Process Bus

Process Bus

A Practical Approach Process bus is generically defined as the digital transmission of process measurements between the substation switchyard and digital protective relays in the control house. The IEC 61850 standard addresses process bus through Part 9-2 "Specific Communication Service Mapping (SCSM) - Sampled values over ISO/IEC 8802-3", by providing data mapping to transmit analog sam... More

The Guru

Gerhard Ziegler

PAC World: Can you tell us something about where you were born and where you grew-up?G.Z: I was born 1939 in Berlin. But during the war our house was bombed and we went back to the rural Franconia near Nuremberg where both my parents are from. So I am not a real Berliner. I grew up in the after war time in a then small village where the roads were not paved and water had to be fetched at a ... More


Protection History. Generator Protection

Introduction In the beginning of electrical power supply (1880-1890) the importance of switching devices was minor. Small units for illumination of a house and commercial building had been put into operation. Knife switches, strip fuses and a simple bulb for supervision of voltage were sufficient for dynamos with a power of 15...25 kW. Edison,T.A. started running the first cent... More

I Think

Using experience to innovate

When I started my career, just like many young engineers, I was full of plans and ideas to improve the world and make the Power Industry better, more efficient and innovative. Just like many young engineers today I was surrounded by experienced engineers that could not resist telling me great stories about everything that went or that could go wrong. The stories were indeed great and they ins... More

Industry Reports

Coordinating European Transmission

The "Union for the Co-ordination of Transmission of Electricity" (UCTE) is the association of transmission system operators in twenty four countries in continental Europe, providing a reliable market platform to all participants of the Internal Electricity Market ( IEM ) and beyond by efficient and secure electric "power highways". Fifty years of joint activities laid the basis for a l... More

IEEE Guide for Distribution Protection

IEEE C37.230, Guide for Protective Relay Applications to Distribution Lines. The IEEE PESPSRC Line Protection Subcommittee formed Working Group D5 to develop a guide to describe principles, practices and special topics in protecting distribution lines. The result of the working group's efforts is IEEE Standard C37.230 Guide for Protective Relay Applications to Distribution Lines. T... More

Conference Reports

Clemson Power Systems Conference 2009

The 2009 Power System conference was organized by Clemson University and held 10-13 March 2009. The conference program included multiple tutorials, panel and paper sessions covering different topics of interest to the electric power systems protection, automation and control industry. The tutorial topics were: Innovation you can use today Introduc... More

DistribuTECH and Transtech 2009, February 3 -5

Conference and exhibition on automation, information technology and T&D engineering for the Utility Industry, San Diego, CA, USA. The 19th DistribuTECH and Transtech Conference & Exhibition was held from February 03 to 05, 2009 at the Sand Diego Convention Center in San Diego (California, USA). It is a key event in North America. The event offered many opportunities to electri... More

Georgia Tech Fault & Disturbance Analysis Conference

The two conferences were organized by Georgia Tech in five consecutive days. The 12th Annual Georgia Tech Fault and Disturbance Analysis Conference was held 20-21 April 2009 in Atlanta, Georgia, USA at the Georgia Tec Global Learning Center. Twenty papers were presented in four sessions during the two days of the conference. The papers covered a wide range of subjects - analysis... More

Georgia Tech Protective Relaying Conference

The 63rd Annual Georgia Tech Protective Relaying Conference was held 22-24 April 2009 in Atlanta, Georgia, USA. The venue of the conference was the historical Fox theatre. Forty papers selected by the program committee were presented by authors from around the world in ten sessions during the two and a half days of the conference. Most of the sessions were running in parallel in the... More

South East Asian Protection & Automation Conference

The SEAPAC was held in Melbourne, Australia - 17-18 March, 2009. The welcoming remarks by the chairman of the conference Rodney Hughes were followed by the first day keynote speaker - Simon Bartlett, from PowerLink, Australia, who discussed different issues related to the "Secondary Systems in Today' s Power Systems". The second day keynote speaker was Marco Janssen from UTInnovation... More

Texas A&M Protective Relay Conference, USA

The 62nd Annual Conference for Protective Relay Engineers was held in College Station, Texas, USA, and was hosted by Texas A&M University. In his Welcome address the conference Chair Prof. B. Don Russell writes: "For 62 years the Annual Conference for Protective Relay Engineers has provided the best available information on protective relay applications and technology. With t... More

Western Power Delivery Automation Conference, 2009

This conference focuses on the issues of automation and control of power system substations. The 11th annual Western Power Delivery Automation Conference 2009 was organized by Washington State University and held at the historical Davenport hotel in Spokane, WA from 6 to 9 April, 2009. At a time when Smart Grid is becoming a topic of discussions even in the media and billions o... More

Book Review

Practical Power System Protection

The book is edited by Dr. P. K. Shetty and Shri V. K. Agrawal A book titled "Grid Security and Management " was published by Power Line Publishing, India a publisher of Power Line magazine dedicated to the power and energy sector. The book was released on 7th April 2009 in New Delhi, India. Electricity is the prime mover of economic growth in a country and vital to the sustenance of... More


Fine ArtFine Art by Prof. James Thorp

PAC World magazine is introducing the art of Prof. James Thorp. It is amazing how little we know about the hobbies of our colleagues and how we find out about them. When I visited Stan Horowitz for his Guru interview, I noticed on the wall in his apartment a large painting that looked like a Jackson Pollock. Knowing how expensive they are, I asked Stan about it. He smiled and told me t... More

Final Thoughts
Tell us your opinion about the names of the PAC World issues during the year. Should we use the seasons? This is the question we asked on the PAC World web site three months ago. We wanted to hear your opinion about the way we label the individual issues within the year. You had to choose from the following options: Use the month when the magazine is mailed - (example Mar... More

Power. Flexible. Easergy.
Protecting your electrical assets? today and tomorrow