Short Circuits in Power Systems

A Practical Guide to IEC 60909-0

Ismail Kasikci

• Verlag: Wiley-VCH
• Jahr: 2017
• ISBN:
  9783527803385
• Auflage: 2
• Thema: Technik & Maschinenbau
• Thema: Energieressourcen

Reflecting the changes to the all-important short circuit calculations in three-phase power systems according to IEC 60909-0 standard, this new edition of the practical guide retains its proven and unique concept of explanations, calculations and real-life examples of short circuits in electrical networks. It has also been completely revised and expanded by 20% to include the standard-compliant prevention of short circuits in electrical networks for photovoltaics and wind energy. By understanding the theory any software allows users to perform all the necessary calculations with ease so they can work on the design and application of low- and high-voltage power systems.
This book is a practitioner's guide intended for students, electrical engineers, engineers in power technology, the electrotechnical industry, engineering consultants, energy suppliers, chemical engineers and physicists in industry.

Chapter 1
Definitions: Methods of Calculations

The following terms and definitions correspond largely to those defined in IEC 60909-0. Refer to this standard for all the terms not used in this book.

The terms short circuit and ground fault describe faults in the isolation of operational equipment, which occur when live parts are shunted out as a result.

1. 1. Causes:
   • Overtemperatures due to excessively high overcurrents;
   • Disruptive discharges due to overvoltages; and
   • Arcing due to moisture together with impure air, especially on insulators.
2. 2. Effects:
   • Interruption of power supply;
   • Destruction of system components; and
   • Development of unacceptable mechanical and thermal stresses in electrical operational equipment.
3. 3. Short circuit: According to IEC 60909-0, a short circuit is the accidental or intentional conductive connection through a relatively low resistance or impedance between two or more points of a circuit that are normally at different potentials.
4. 4.
   Short-circuit current: According to IEC 60909-0, a short-circuit current results from a short circuit in an electrical network.
   It is necessary to differentiate between the short-circuit current at the position of the short circuit and the transferred short-circuit currents in the network branches.
5. 5. Initial symmetrical short-circuit current: The effective value of the symmetrical short-circuit current at the moment at which the short circuit arises, when the short-circuit impedance has its value from the time zero.
6. 6. Initial symmetrical short-circuit apparent power: The short-circuit power represents a fictitious parameter. During the planning of networks, the short-circuit power is a suitable characteristi...