By Sylvie Perrin and Vincent Sermanson, RTE, France The Iberian blackout that occurred on April 28, 2025, at 12:33 PM was classified as a Level 3 incident—the highest...
Issue 077 September 2026
Cover Art

Cover Story
Featured Articles
Chilean Grid Blackout of February 2025:
Causes and Lessons By Víctor Velar, Jaime Peralta, Carlos Alvear, and Eugenio Quintana, Coordinador Eléctrico Nacional (CEN), Chile At 15:15:41 local time on Tuesday, February 25, 2025, an...
Why is the Grid Changing
By Janio Leonardo Los, Ricardo Lira, Marcelo Cascardo Cardoso, Independent System Operator, Brazil Power systems were designed around large synchronous generators. Their rotating masses store kinetic...
Improving Grid Performance and Reliability – A Statutory...
By Matthew Lewis, Manager of Event Analysis, NERC, USA “Gentlemen, we are always going to relentlessly chase perfection, knowing full well we will not catch it because nothing is perfect. In the...
An Interesting Overreach mis-operation and the process of...
by Paul Hodges, Tampa Electric, USA Acknowledgment: The author would like to acknowledge and thank Jai Subbarayan at Schweitzer Engineering Laboratories Inc. (SEL) for his assistance and...
Editorial
Editorial – Issue 077 September 2026
by Alex Apostolov, Editor-in-Chief The Changing Face of Fault and Disturbance Analysis Every time I sit down to write about disturbance recording and analysis, I am reminded that this is one of the...
Last Word
AI – Reshaping Fault and Disturbance Analysis
by Alex Apostolov, USA Fault and disturbance analysis has always sat at the heart of power system protection engineering. When a breaker trips, a relay operates, or a transient ripples through a...
The Guru
Interview with PACWorld Guru: Prof. Dr. Omer Usta
PAC World: When and where were you born? O.U.: I was born in 1959 in Trabzon, which is a major city on the Black Sea cost of northeastern part of Turkiye. Founded in 756 BC, it serves as a...
History
Walter Schossig: A Lifetime Dedicated to Keeping the Lights On
by Thomas Schossig, OMICRON electronics GmbH, Austria Since the very first edition of PAC World, Walter has been a valued contributor to our magazine. His first paper, “Introduction to the History of...


