Short Circuits in Power Systems (eBook)

Ismail Kasikci is Professor at the University of Applied Sciences Biberach, Germany. His main research area is electrical energy supply, design of electrical installations of buildings, solar electricity, wind power generation, building integrated renewables, design and protection of distribution power system, smart grids, solar and wind power, connectivity requirements, focused on the IEC/EN and VDE regulations. Ismail Kasikci received his Bachelor in electrical and electronics engineering from the Technical University Darmstadt and his PhD from the University of Brunel, United Kingdom. He published 17 books in German, English and Turkish and more than 64 international scientific publications. He is a member by VDE and IEEE. He is Associated Editor of the international Journal of Power and Energy Systems by ACTA press in the States and Canada. Since 2005 he is a member of the German norm group, K221 [IEC TC 64 (VDE 0100)]. He has more than 18 years of professional experience in planning and design of electrical power systems. He plays since 1994 an active role in Turkey for educational purposes and in the regulation of IEC and EN. Within the scope of the EU Erasmus program he gives lectures at the University of Pamukkale and Ege University in the field of Electric Power Systems, Grounding and Protection.

TERMS AND DEFINITIONS
Time Behavior of the Short Circuit Current
Short Circuit Path in the Positive-Sequence System
Classification of Short Circuit Types
Methods of Short Circuit Calculation
Calculating with Reference Variables
GENERAL INFORMATION ABOUT IEC 60 909
THE SIGNIFICANCE OF IEC 60 909
SUPPLY NETWORKS
Calculation Variables for Supply Networks
Lines Supplied from a Single Source
Radial Networks
Ringnetworks
Meshed Networks
NETWORK TYPES FOR THE CALCULATION OF SHORT CIRCUIT CURRENTS
Low Voltage Network Types
Medium Voltage Network Types
SYSTEMS UP TO 1 KV
TN Systems
Calculation of Fault Currents
TT Systems
IT Systems
Transformation of the Network Types Described to Equivalent Circuit Diagrams
NEUTRAL POINT TREATMENT IN THREE-PHASE NETWORKS
Networks with Isolated Free Neutral Point
Networks with Grounding Compensation
Networks with Low Impedance Neutral Point Treatment
IMPEDANCES OF THREE-PHASE OPERATIONAL EQUIPMENT
Network Feed-Ins
Synchronous Machines
Transformers
Short Circuit Current on the Secondary Side
Voltage Regulating Transformers
Cables and Overhead Lines
Short Circuit Current Limiting
Asynchronous Machines
Consideration of Capacitors and Non-Rotating Loads
Consideration of Static Converters
IMPEDANCE CORRECTIONS
Correction Factor KG for Generators
Correction Factor KKW for Power Plant Block
Correction Factor KT for Transformers with Two and Three Wind
THE METHOD OF SYMMETRICAL COMPONENTS
Symmetrical Components
Impedances of Symmetrical Components
CALCULATION OF SHORT CIRCUIT CURRENTS
Three-Pole Short Circuits
Two-Pole Short Circuits with Contact to Ground
Two-Pole Short Circuit Without Contact to Ground
Single-Pole Short Circuits to Ground
Peak Short Circuit Current Ip
Symmetrical Breaking Current Ia
Steady State Short Circuit Current Ik
MOTORS IN THREE-PHASE NETWORKS
Short Circuits At the Terminals of Asynchronous Motors
Motor Groups Supplied from Transformers with Two Windings
Motor Groups Supplied from Transformers with Different Nominal Voltages
MECHANICAL AND THERMAL SHORT CIRCUIT STRENGTH
Mechanical Short Circuit Current Strength
Thermal Short Circuit Current Strength
Limitation of Short Circuit Currents
CALCULATIONS FOR SHORT CIRCUIT STRENGTH
Short Circuit Strength for Medium Voltage Switchgear
Short Circuit Strength for Low Voltage Switchgear
EQUIPMENT FOR OVERCURRENT PROTECTION
Short Circuit Currents in DC Systems
Resistances of Line Sections
Current Converters
Batteries
Capacitors
DC Motors
PROGRAMS FOR THE CALCULATION OF SHORT CIRCUIT CURRENTS
EXAMPLES: CALCULATION OF SHORT CIRCUIT CURRENTS
Example 1: Radial Network
Example 2: Proof of Protective Measures
Example 3: Connection Box to Service Panel
Example 4: Transformers in Parallel
Example 5: Connection of a Motor
Example 6: Calculation for a Load Circuit
Example 7: Calculation for An Industrial System
Example 8: Calculation of Three-Pole Short Circuit Current and Peak Short Circuit Current
Example 9: Meshed Network
Example 10: Supply to a Factory
Example 11: Calculation with Impedance Corrections
Example 12: Connection of a Transformer Through An External Network and a Generator
Example 13: Motors in Parallel and Their Contributions to the Short Circuit Current
Example 14: Proof of the Stability of Low Voltage Systems
Example 15: Proof of the Stability of Medium and High Voltage Systems
Example 16: Calculation for Short Circuit Currents with Impedance Corrections
Example 17: Calculation with Per-Unit Magnitudes