Chapter 1 describes the evolution of the power industry over the last 25 years. The changing character of the power industry, with its increasing dependence on the interconnected transmission grid, has created many problems, the most pressing of which is how to improve operational security. Recent events are described, showing that the analysis of so-called normal events, even though ensuring basic system strength and acceptable security limits, is not likely to provide a sufficient margin for the multiple simultaneous events that affect power transmission systems. In this context, the concept of Defense Plan is introduced as a method of providing effective measures that will reduce the likelihood of blackouts.

Chapter 2 presents existing defense plans. The numerous schemes described demonstrate that, despite geographical and regulatory differences, the concept of improving system security can evolve in multiple ways. This chapter presents the summary description, basic philosophy, and coordination issues related to these various schemes.

Chapter 3 addresses the complex issues of power system analysis from the perspective of extreme contingencies. Analysis of a power system that is at the edge of instability following multiple events is very challenging and of questionable accuracy. Analysis tools such as stability programs and model parameters must be assessed under these types of stress system conditions. The continuing advances in the development of analytical tools and study procedures for various types of disturbances are also discussed.

Chapter 4 discusses these issues and identifies different ways to reduce the likelihood of extreme contingencies through more stringent design criteria and improved operational practices.

Chapter 5 lists and evaluates all possible means of action (that is, SPSs) that could be used in a Defense Plan to respond to extreme contingencies, and offers guidelines to help in the selection of the most appropriate one based on the type of instability encountered. It briefly reviews the main power system phenomena, SPS actions available, and the main factors to be considered in the selection of the most appropriate SPS.

Chapter 6 focuses on the design and deployment of an Overall Defense Plan that will help manage system disturbances and prevent blackouts. The relative time of action for different types of events varies from normal to extreme, depending on the nature and speed of the disturbance and the need for coordination. The deployment of an Overall Defense Plan requires implementation and coordination of a number of schemes and actions spanning various time periods. Building on the basic specifications, the plan must consider reliability issues, operational and maintenance criteria, redundancy, coordination with other plans, available technologies, and telecommunications.

Chapter 7 discusses architectural aspects as well as engineering considerations. This chapter presents a comprehensive listing of measurements, status variables, a review of the types of telemetry applications (transducer, digitized, floating points) and transmission of the analog values, and descriptions of practical methodologies for automatic arming. Operational control system requirements are listed, including tools for visibility, event recording and automatic analysis.

Chapter 8 provides a broader perspective of the new mega-infrastructure that is emerging from the convergence of energy (including the electric grid and water, oil and gas pipelines), telecommunications, transportation, the Internet, and electronic commerce. New ways are being sought to improve network efficiency and eliminate congestion in the power grid and other critical infrastructures, without significantly diminishing reliability and security. Because of the unique attributes of the electricity infrastructure, advanced technology will necessarily play an important role in efforts to improve security. Assuming that individual utilities are already undertaking prudent steps to improve physical security wherever possible, technology can make a vital contribution by enhancing the inherent resilience and flexibility of power systems in terms of withstanding natural disasters or attacks.

The Conclusion summarizes the main topics that are addressed in the report, and presents the recommendations of the Task Force on Defense Plans.

Task Force C2.02.24
Jean-Marie Gagnon, (CA) - Convener

Chapter Coordinators:
Chapter 1 - Walter Lachs (AU)
Chapter 2 - Paulo Gomes (BR)
Chapter 3 -Miroslav Begovic (USA)
Chapter 4 - Bermont Truchon (CA)1 / Peter Donalek
Chapter 5 - Gilles Trudel (CA)
Chapter 6 - Novosel, Damir (USA)
Chapter 7 - Madani, Vahid (USA)
Chapter 8 - Chen-Ching Liu (USA)

Main Contributors:
Massoud Amin (USA), Harrison Clark (USA) Ian Dobson (USA)
Peter Donalek (USA) Robert Grondin (CA) Shinichi Imai (JP)
Danny Julian (USA) Daniel Karlsson (SW) Oystein Kirkeluten (NO)
Uhlen Kjetil (NO) Borka Milosevic (USA) Carson Taylor (USA)
Khoi Vu (USA) Louis Wehenkel (BE).

Sandro Corsi (IT)
Alfredo Vaccaro (IT)



Power. Flexible. Easergy.
BeijingSifang June 2016