Network Protection & Automation Guide (NPAG)

In order to provide the modern practicing substation engineer with reference material, AREVA's Network Protection & Automation Guide provides a substantially revised and expanded edition of PRAG incorporating new chapters on all levels of network automation.


The first part of the book deals with the fundamentals, basic technology, fault calculations and the models of power system plant, including the transient response and saturation problems that affect instrument transformers.

The typical data provided on power system plant has been updated and significantly expanded following research that showed its popularity.

The book then provides detailed analysis on the application of protection systems. This includes a new chapter on the protection of a.c. electrified railways. Existing chapters on distance, busbar and generator protection have been completely revised to take account of new developments, including improvements due to numerical protection techniques and the application problems of embedded generation. The chapter on relay testing and commissioning has been completely updated to reflect modern techniques. Finally, new chapters covering the fields of power system measurements, power quality, and substation and distribution automation are found, to reflect the importance of these fields for the modern power system engineer.

The intention is to make NPAG the standard reference work in its' subject area - while still helping the student and young engineer new to the field.

To obtain the NPAG book, by download or CD-ROM, please use the contact form in the link below.


The following is a short description of the content of the individual chapters of NPAG:

Chapter 06 Current and Voltage Transformers

Whenever the values of voltage or current in a power circuit are too high to permit convenient direct connection of measuring instruments or relays, coupling is made through transformers. Such 'measuring' transformers are required to produce a scaled down replica of the input quantity to the accuracy expected for the particular measurement; this is made possible by the high efficiency of the transformer. The performance of measuring transformers during and following large instantaneous changes in the input quantity is important, in that this quantity may depart from the sinusoidal waveform.

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