Switching in Electrical Transmission and Distribution Systems

Preface

At the turn of the nineteenth century, a revolution took place in electrical engineering. In a rather short time, the transformer was invented, electric generators and motors were designed, and the step from DC to AC transmission was made. At the beginning of the twentieth century, the transmission voltages were steadily increased to reduce transmission losses. To improve operating efficiency, power systems began to be interconnected. Reserve power or spinning reserve could be then shared and capital expenditure could be reduced.

This is where “power” switching came in with its major task: isolating the faulted section of the system while keeping in service all healthy parts. Nowadays the power system can be regarded as one of the most complex systems ever designed, built and operated. Despite its complexity and robustness, the switching technology facilitates consumers to connect and disconnect electric loads in a rather simple and reliable way. Moreover, it protects the system from the effects of faults. However, this comes at a price since every change in the state of a system generates transients that may affect both the operating conditions of the system and its components.

With the first application of power switching in early electric systems, the development of standards for rating, testing and manufacturing high-voltage circuit-breakers began. In the United States, initiative was taken by a number of engineering and manufacturer trade organizations, such as ...