Preface

There are seven Parts to this Book consisting of 19 chapters:

Part I, "Introduction," provides background on the definition of a resilient control system and its application to the power system use case.

Chapter 1: This chapter outlines a course designed to introduce students from multiple science and engineering disciplines to the challenges of automation in the power system. As more automatic control systems are applied, the resulting complexity and vulnerabilities increase the need for resilient control systems. A resilient control system "maintains state awareness and an acceptable level of operational normalcy in response to disturbances" [1]. The chapter also discusses the expected outcomes of the course.

Chapter 2: The electric power system is a fundamental infrastructure that is critical to everyday life. Resilient design and resilient control of the power grid are essential. This chapter will introduce the power system as a use case to demonstrate the concepts of resilient control system design. The use case will illustrate how power systems measurements and control are implemented using autonomous control devices, both in normal operation and during larger disturbances. Later chapters will show how modern control approaches can improve system resilience. The use case also considers the human system operator interface and the importance of applying human factors to allow automation to support the human operators to ensure the human-in-the-loop can concentrate on what humans do best. The use case also allows exploration of cybersecurity and cyber-defense concerns.

Part II, "Infrastructure Fundamentals," provides a background on the design of current power system designs, including the integrated control and communications systems.

Chapter 3: Power system architectures evolved over a period of more than 100?years. The power grid from the 1960s to the late 1990s will be referred to as a "traditional architecture." This architecture was the result of 60?years of gradual evolution. Recent decades have seen accelerating changes. Emerging trends, especially those driven by the significant increase of renewable power generation sources, the evolution of power markets, and the advent of microgrids, will be described. The chapter will discuss power systems operations and control, including the roles of human operators. In addition, the power system planning process will be introduced in this chapter, followed by a discussion of measures of operational performance used for transmission and distribution operations.

Chapter 4: The most important control of electric power generation is the inherent detection of load demand changes. The first response mechanism is to keep the production and the consumption operating in balance. The second response mechanism is to maintain the voltage level within tolerance for the operation of loads. The power and voltage control at generation units is a primary problem in power-system design. The control of individual generators has evolved into a hierarchical control for the management of large interconnections. Modern energy control centers command the generation levels and supervise the flow of power across the grid.

The control of alternative current (AC) power systems is benefited by the inherent ability of electric generation to detect the load demand changes without any communication and control infrastructure. The basic response mechanism to keep the balance between electric power production and consumption comes from the turbine-generator response to the conservation of energy. The control of generator units is the primary control problem of power systems. The methods developed for control of individual generators and of large interconnections play a vital role in energy control centers.

Chapter 5: The electric power utility system has, over the past several decades, become highly dependent upon high-speed, reliable communications systems. This evolution has gone from simple human-to-human communication for the manual operation of the system to a variety of systems and subsystems. These include systems such as Supervisory Control and Data Acquisition (), Distribution Automation (DA), system protection including specialized systems dependent upon communication, and more modern systems for security and surveillance, condition monitoring, asset management, and customer billing.

Part III, "Disciplinary Fundamentals," provides background on the unique disciplinary foundations that are brought to bear in this text.

Chapter 6: This chapter argues that an interdisciplinary education is critical to addressing the complex problems of today. Engineering curricula traditionally provide students with a broad education, but additional work must be done to help students appreciate the unique contributions of members of an interdisciplinary team. Because resilient solutions are not found in any one system, interdisciplinary teams are critical to success. Initiatives such as the Resilient Control Systems for the Power Grid course and the GridGame promote have been developed to help students understand multiple roles and perspectives within the resilience community.

Chapter 7: Cyber-Physical Systems (CPS) or Industrial Control Systems (ICS), such as the power grid and manufacturing plants, are systems that are comprised of an array of interconnected physical, control, computing, and networking devices. Often, such systems bear vulnerabilities in either their physical or digital components, which in turn may expose them to threats and render them susceptible not only to physical but also cyberattacks. In this chapter, we will examine the main elements of security within the context of ICS/CPS and focus on its cybersecurity aspects. We will analyze the main properties of cybersecurity, namely confidentiality, integrity, and availability, and study the most important technical mechanisms that exist to ensure these properties, including cryptography, authentication, authorization, accountability, access control, and redundancy. We will describe the common types of vulnerabilities in ICS/CPS and inspect the main stages of a cyberattack. We will also provide pointers of system design principles that must be followed during the various stages of the ICS/CPS lifecycle to increase their security. Finally, the most important approaches for threat and risk mitigation will also be outlined.

Chapter 8: Control Theory addresses the feedback principles of any dynamical system where the output is fed back via a controller for comparison with the desired input to make any necessary changes to satisfy the customer specifications. Dynamical systems exist in various forms such as linear or nonlinear, continuous or discrete, deterministic or stochastic, etc. The field of control systems has a long history dating back to 300 BCE when the Greeks invented a water clock and with a formal work on governors by James Clerk Maxwell in 1868, leading to classical control era (Routh-Hurwitz, Bode, Nyquist) and modern control era (Lyapunov, Pontryagin, Kalman, etc.). This chapter presents an overview of the theory and techniques arising in modern control systems such as optimal control, and briefly touch upon nonlinear control, adaptive control, intelligent control, etc. Any engineering system to be controlled needs to have three components of modeling, analysis or performance, and synthesis or design. Optimization is a very desirable feature in day-to-day life. We like to work and use our time in an optimum manner, use resources optimally, and so on. The main objective of optimal control is to determine control signals that will cause a process (plant) to satisfy some physical constraints and at the same time extremize (maximize or minimize) a chosen performance criterion (performance index or cost function). Thus, we address optimal control systems where the theory is rooted in the field of calculus of variations developed during sixteenth and seventeenth centuries over 300?years ago [2] and flourished right into the twenty-first century.

Chapter 9: This chapter reviews user-centered design for human-system interfaces of control systems. The premise of user-centered design is that the designer must consider the user, in this case the operator of a control system. User-centered design also advocates for iteration, in which feedback from operator testing is used to improve the design of the system. This chapter walks through the importance of keeping humans in the loop in control systems design and then outlines approaches for design planning, prototyping, and evaluation. It concludes with a checklist to help the control systems engineer follow a user-centered process in the design of human-system interfaces.

Part IV, "Metrics Fundamentals," establishes a basis for measuring success in the area of resilience.

Chapter 10: The improvement of resilience in electric power systems has been of growing importance in the United States for several years. Progress has been made in various areas, but much remains to be done in terms of the basic architecture of the power grid. A limiting factor has been the lack of a connection between foundational grid architecture principles and methods on the one hand and clearly defined relationships between resilience improvement objectives and actual means for...