The need to improve electric supply systems is stipulated by development of industry, transport, civil engineering and the agroindustrial complex. These enterprises are the main consumers of electric power in complex infrastructure of industrial centers. They consume electric power with different frequencies, voltages and currents. They are also characterized by high density of electric loads. Their electric supply systems have multilevel stages of power distribution; large-scale load centers with different transformations of electromagnetic energy parameters, power consumers of various types; power sources of power system, local thermal power stations, synchronous compensators, sources of reactive power, in emergencies - motors went to generating mode; significant degree of branching; characterized by negative feedback of electric technological processes and powerful consumers on the system operation in emergencies.

Construction and maintenance of the electric power supply systems involves considerable material resources. That is why it is very important to improve their efficiency and reliability in different operating conditions, including malfunctions and post-emergency inodes. This stipulates high requirements to these systems, to their operating modes and electric power quality. These requirements can be assessed on the basis of transients investigation.

Methods of investigation and evaluations of transients is the important field of research and development in NIS and western countries. Their aim is the development of new level electric power supply systems, sustaining their modes stability with required levels of economy, electric power quality, reliability, and maintenance safety. Use of simulation methods and computing aids greatly contributes to solving tasks arising at analysis and evaluations of transients. They allow to choose the most appropriate circuit designs and electric characteristics of the system components, and also to forecast their economical and technical performances not only in normal, but also in transient modes.

Questions are analyzed and illustrated by examples with use of language structures, which will assist to students’ self-instruction, their comprehension of teaching material and mastering in modem research and evaluations principles in English.

The book consists of introduction and the main part, were electromagnetic transients caused by shorts, longitudinal and lateral asymmetry are considered. Chapter 1 covers starting positions, basic assumptions and principles of equivalent representation for analysis of transients in electric power supply system. Equivalents of electric supply system elements and its mode parameters are the basis for construction of equivalent circuits (chapter 1), which are used for analytical (chapter 2) and practical (chapter 3) calculations of three-phase short circuits. Various types of lateral (chapter 5), longitudinal asymmetry (chapter 6), their combinations and complex faults are analyzed using method of symmetrical components. Influence of technologies and electric consumers operating modes on supply networks is illustrated in chapter 7. Measures of short circuit currents and power limitation are considered in chapter 8. There are also conditions for their levels’ optimization formulated.

There are control questions and topics for essays at the end of each chapter for better comprehension of given material. They will help students’ self-dependent activities in EST learning terminology of the discipline.

Authors will gratefully accept remarks and readers’ opinion, which will assist to further development of this text-book.

Acknowledgments

Authors wish to thank O. Balakhontsev, V. Gavrilyuk and L. Tokar, who have translated the book into English; Professors S. Kostritskaya and O. Ivanov for editing the English version of the textbook; assisting lecturer S. Dybrin and students A. Yefimenko, O. Mikhaylenko who have prepared the computer version of the edition.