A key premise of the book is that the design of successful control systems requires a deep understanding of the processes to be controlled; as such, the technical discussion begins with a concise review of the physical foundations of electricity and magnetism. This is followed by an overview of nonlinear circuits that include resistors, inductors, capacitors, and memristors, along with an examination of basic circuit mathematical models and formulations. AC power systems are considered next, in which models for their basic components are derived. The following chapters address power system dynamics using both the ordinary differential equation and differential-algebraic equation models of a power network, as well as bifurcation analysis and the behavior of a network as it approaches voltage instability. Two classic control problems – voltage regulation and load-frequency control – are then described, including the coordination of economic dispatch with load-frequency control. Finally, power system control problems involving operation in highly nonlinear regimes and subjected to discrete failure modes are discussed. will appeal to practicing power system engineers, control systems engineers interested in powersystems, and graduate students in these areas. Because it provides sufficient information about their modelling and behavior, control engineers without a background in power systems will also find it to be a valuable resource.