For many decades distribution systems protection has been considered a no brainer due to the simple radial configuration with a single source at the substation, thus making the use of time-overcurrent protection coordinated with downstream fuses and reclosers the state of the art in the twentieth century. The loss of power to residential customers for short periods of time was also not considered a major problem.

The world however has changed, and now neither of the above is true. Distributed energy resources connected to the distribution system, as well as the requirements for reducing the fault clearing time are some of the drivers for a different approach to distribution systems protection.
That is why the third edition of “Protection of Electricity Distribution Networks” is a timely update of the popular book that represents a practical resource for graduate students, practicing engineers and many others with interest in the subject.
The authors of the book are two engineers with huge practical and teaching experience that well understand the subject matter, as well as how to present it in an understandable manner.
After the introduction, the second chapter of the book describes methods for calculation of short-circuit currents, before going into the distribution protection issues that are the main subject of the book.
After the classification of protection functions in Chapter 3 and the discussion of current and voltage transformers as the interface of the protection relays with the distribution system in Chapter 4, the authors go into the details of specific types of protection functions used at the distribution level of the electric power system.
The main distribution protection functions covered in the following five chapters are: 

• Overcurrent protection
• Fuses
• Reclosers and sectionalizers
• Directional overcurrent
• Differential and distance protection

The next two chapters of the book address issues related to the protection of industrial systems and load shedding in case of abnormal conditions or system disturbances. Protection schemes and substation design are later discussed, including the use of the earlier described types of protection combined in protection schemes and their application to the different types of substation one-line diagrams.

This third edition contains a new chapter that to the greatest extent reflects the changes in the industry - communication networks for power systems automation. It includes an overview of IEC 61850, the substation configuration language, GOOSE, process bus and substation IT networks.
The last chapter of the book concentrates on the very important issues of installation, testing and maintenance of protection systems.
When appropriate, some of the chapters of the book include exercises that can help the reader apply the knowledge obtained from going through the material. Solutions to the examples are given in an appendix at the end of the book.