Analysis and Design of Electrical Power Systems

Ismail Kasikci, PhD, is a retired Professor at the University of Applied Sciences Biberach, Germany. His main area of research focuses on the IEC/EN and VDE regulations of electrical energy supply, design of electrical installations of buildings, solar electricity, wind power generation, building integrated renewables, design and protection of distribution power systems, smart grids, solar and wind power, and connectivity requirements. He is an active member in various national and international standards committees in the field of electrical and electronics engineering.

• Preface xvAcknowledgments xviiSymbols xixAbbreviations xxvii1 Introduction 12 Electrical Systems 52.1 High-Voltage Power Systems 52.2 Transformer Selection Depending on Load Profiles 92.3 Low-Voltage Power Systems 102.4 Examples of Power Systems 172.4.1 Example 1: Calculation of the Power 172.4.2 Example 2: Calculation of the Main Power Line 172.4.3 Example: Power Supply of a Factory 173 Design of DC Current Installations 213.1 Earthing Arrangement 213.2 Protection Against Overcurrent 223.3 Architecture of Installations 234 Smart Grid 255 Project Management 275.1 Guidelines for Contracting 275.2 Guidelines for Project Planning of Electrical Systems 286 Three-Phase Alternating Current 316.1 Generation of Three-Phase Current 316.2 Advantages of the Three-Phase Current System 316.3 Conductor Systems 326.4 Star Connection 366.5 Triangle Circuit 376.6 Three-Phase Power 386.7 Example: Delta Connection 396.8 Example: Star Connection 416.9 Example: Three-Phase Consumer 436.10 Example: Network Calculation 446.11 Example: Network 456.12 Example: Star Connection 477 Symmetrical Components 497.1 Symmetrical Network Operation 497.2 Unsymmetrical Network Operation 517.3 Description of Symmetrical Components 517.4 Examples of Unbalanced Short-Circuits 547.4.1 Example: Symmetrical Components 547.4.2 Example: Symmetrical Components 547.4.3 Example: Symmetrical Components 558 Short-Circuit Currents 578.1 Introduction 578.2 Fault Types, Causes, and Designations 608.3 Short-circuit with R–L Network 618.4 Calculation of the Stationary Continuous Short-circuit 638.5 Calculation of the Settling Process 648.6 Calculation of a Peak Short-Circuit Current 658.6.1 Impact Factor for Branched Networks 658.6.2 Impact Factor for Meshed Networks 658.7 Calculation of the Breaking Alternating Current 668.8 Near-Generator Three-Phase Short-circuit 668.9 Calculation of the Initial Short-Circuit Alternating Current 678.10 Short-Circuit Power 688.11 Calculation of Short-Circuit Currents in Meshed Networks 688.11.1 Superposition Method 688.11.2 Method of Equivalent Voltage Source 708.12 The Equivalent Voltage Source Method 728.13 Short-Circuit Impedances of Electrical Equipment 728.13.1 Network Feeders 738.13.2 Synchronous Machines 748.13.3 Transformers 758.13.4 Consideration of Motors 768.13.5 Overhead Lines, Cables, and Lines 788.13.6 Impedance Corrections 798.14 Calculation of Short-Circuit Currents 818.14.1 Three-Phase Short-circuits 818.14.2 Line-to-Line Short-circuit 828.14.3 Single-Phase Short-circuits to Ground 828.14.4 Calculation of Loop Impedance 838.14.5 Peak Short-Circuit Current 858.14.6 Symmetrical Breaking Current 858.14.7 Steady-State Short-circuit Current 878.15 Thermal and Dynamic Short-circuit Strength 878.16 Examples for the Calculation of Short-Circuit Currents 898.16.1 Example 1: Calculation of the Short-Circuit Current in a DC System 898.16.2 Example 2: Calculation of Short-Circuit Currents in a Building Electrical System 918.16.3 Example 3: Dimensioning of an Exit Cable 928.16.4 Example 4: Calculation of Short-Circuit Currents with Zero-Sequence Resistances 938.16.5 Example 5: Complex Calculation of Short-Circuit Currents 948.16.6 Example 6: Calculation with Effective Power and Reactive Power 978.16.7 Example 7: Complete Calculation for a System 1018.16.8 Example 8: Calculation of Short-Circuit Currents with Impedance Corrections 1118.16.9 Example: Load Voltage and Zero Impedance 1138.16.10 Example: Power Transmission 1169 Relays 1199.1 Terms and Definitions 1199.2 Introduction 1199.3 Requirements 1219.4 Protective Devices for Electric Networks 1219.5 Type of Relays 1229.5.1 Electromechanical Protective Relays 1229.5.2 Static Protection Relays 1229.5.3 Numeric Protection Relays 1229.6 Selective Protection Concepts 1239.7 Overcurrent Protection 1249.7.1 Examples for Independent Time Relays 1269.8 Reserve Protection for IMT Relays with Time Staggering 1269.9 Overcurrent Protection with Direction 1269.10 Dependent Overcurrent Time Protection (DMT) 1299.11 Differential Relays 1319.12 Distance Protection 1339.12.1 Method of Distance Protection 1359.12.2 Distance Protection Zones 1359.12.3 Relay Plan 1359.13 Motor Protection 1389.14 Busbar Protection 1389.15 Saturation of Current Transformers 1409.16 Summary 14110 Power Flow in Three-Phase Network 14310.1 Terms and Definitions 14310.2 Introduction 14310.3 Node Procedure 14510.4 Simplified Node Procedure 14810.5 Newton–Raphson Procedure 15111 Substation Earthing 15511.1 Terms and Definitions 15511.2 Methods of Neutral Earthing 16011.2.1 Isolated Earthing 16211.2.2 Resonant Earthing 16311.2.3 Double Earth Fault 16411.2.4 Solid (Low-Impedance) Earthing 16611.3 Examples for the Treatment of the Neutral Point 16611.3.1 Example: Earth Fault CurrentWhen Operating with Free Neutral Point 16611.3.2 Example: Calculation of Earth Fault Currents 16711.3.3 Example: Ground Fault Current of a Cable 16711.3.4 Example: Earth Leakage Coil 16811.3.5 Example: Arc Suppression Coil 16811.4 Dimensioning of Thermal Strength 16811.5 Methods of Calculating Permissible Touch Voltages 16911.6 Methods of Calculating Permissible Step Voltages 17211.7 Current Injunction in the Ground 17211.8 Design of Earthing Systems 17311.9 Types of Earth Rods 17511.9.1 Deep Rod 17511.9.2 Earthing Strip 17511.9.3 Mesh Earth 17611.9.4 Ring Earth Electrode 17711.9.5 Foundation Earthing 17711.10 Calculation of the Earthing Conductors and Earth Electrodes 17711.11 Substation Grounding IEEE Std. 80 17811.11.1 Tolerable Body Current 17811.11.2 Permissible Touch Voltages 17911.11.3 Calculation of the Conductor Cross Section 18011.11.4 Calculation of the Maximum Mesh Residual Current 18111.12 Soil Resistivity Measurement 18211.13 Measurement of Resistances and Impedances to Earth 18411.14 Example: Calculation of a TR Station 18411.15 Example: Earthing Resistance of a Building 18611.15.1 Foundation Earthing REF 18611.15.2 Ring Earth Electrode 1 RER1 18711.15.3 Ring Earth Electrode 2 RER2 18711.15.4 Deep Earth Electrode RET 18711.15.5 Total Earthing Resistance RETotal 18811.16 Example: Cross-Sectional Analysis 18811.17 Example: Cross-Sectional Analysis of the Earthing Conductor 18911.18 Example: Grounding Resistance According to IEEE Std. 80 19011.19 Example: Comparison of IEEE Std. 80 and EN 50522 19311.20 Example of Earthing Drawings and Star Point Treatment of Transformers 19411.21 Software for Earthing Calculation 19911.21.1 Numerical Methods for Grounding System Analysis 19911.21.2 IEEE Std. 80 and EN 50522 20311.21.3 Summary 21712 Protection Against Electric Shock 21912.1 Voltage Ranges 22112.2 Protection by Cut-Off orWarning Messages 22212.2.1 TN Systems 22212.2.2 TT Systems 22412.2.3 IT Systems 22612.2.4 Summary of Cut-Off Times and Loop Resistances 22812.2.5 Example 1: Checking Protective Measures 22912.2.6 Example 2: Determination of Rated Fuse Current 23112.2.7 Example 3: Calculation of Maximum Conductor Length 23112.2.8 Example 4: Fault Current Calculation for a TT System 23112.2.9 Example 5: Cut-Off Condition for an IT System 23212.2.10 Example 6: Protective Measure for Connection Line to a House 23212.2.11 Example 7: Protective Measure for a TT System 23313 Equipment for Overcurrent Protection 23513.1 Electric Arc 23513.1.1 Electric Arc Characteristic 23513.1.2 DC Cut-Off 23713.1.3 AC Cut-Off 23713.1.3.1 Cut-Off for Large Inductances 23813.1.3.2 Cut-Off of Pure Resistances 23913.1.3.3 Cut-Off of Capacitances 23913.1.3.4 Cut-Off of Small Inductances 23913.1.4 Transient Voltage 24013.2 Low-Voltage Switchgear 24113.2.1 Characteristic Parameters 24113.2.2 Main or Load Switches 24213.2.3 Motor Protective Switches 24213.2.4 Contactors and Motor Starters 24413.2.5 Circuit-Breakers 24413.2.6 RCDs (Residual Current Protective Devices) 24513.2.7 Main Protective Equipment 24813.2.8 Meter Mounting Boards with Main Protective Switch 24913.2.9 Fuses 25113.2.9.1 Types of Construction 25313.2.10 Power Circuit-Breakers 25613.2.10.1 Short-Circuit Categories in Accordance with IEC 60947 25813.2.10.2 Breaker Types 25913.2.11 Load Interrupter Switches 26013.2.12 Disconnect Switches 26013.2.13 Fuse Links 26113.2.14 List of Components 26114 Current Carrying Capacity of Conductors and Cables 26314.1 Terms and Definitions 26314.2 Overload Protection 26414.3 Short-Circuit Protection 26514.3.1 Designation of Conductors 26814.3.2 Designation of Cables 26914.4 Current Carrying Capacity 27014.4.1 Loading Capacity Under Normal Operating Conditions 27014.4.2 Loading Capacity Under Fault Conditions 27114.4.3 Installation Types and Load Values for Lines and Cables 27314.4.4 Current Carrying Capacity of Heavy Current Cables and Correction Factors for Underground and Overhead Installation 27614.5 Examples of Current Carrying Capacity 28014.5.1 Example 1: Checking Current Carrying Capacity 28014.5.2 Example 2: Checking Current Carrying Capacity 28514.5.3 Example 3: Protection of Cables in Parallel 29014.5.4 Example 4: Connection of a Three-Phase Cable 29314.5.5 Example 5: Apartment Building Without ElectricalWater Heating 29414.6 Examples for the Calculation of Overcurrents 30014.6.1 Example 1: Determination of Overcurrents and Short-Circuit Currents 30014.6.2 Example 2: Overload Protection 30214.6.3 Example 3: Short-Circuit Strength of a Conductor 30314.6.4 Example 4: Checking Protective Measures for Circuit-Breakers 30415 Selectivity and Backup Protection 30915.1 Selectivity 30915.2 Backup Protection 31716 Voltage Drop Calculations 32116.1 Consideration of the Voltage Drop of a Line 32116.2 Example: Voltage Drop on a 10 kV Line 32516.3 Example: Line Parameters of a Line 32516.4 Example: Line Parameters of a Line 32716.5 Voltage Regulation 32816.5.1 Permissible Voltage Drop in Accordance With the Technical Conditions for Connection 32816.5.2 Permissible Voltage Drop in Accordance With Electrical Installations in Buildings 32916.5.3 Voltage Drops in Load Systems 32916.5.4 Voltage Drops in Accordance With IEC 60364 33016.5.5 Parameters for the Maximum Line Length 33016.5.6 Summary of Characteristic Parameters 33316.5.7 Lengths of Conductors With a Source Impedance 33416.6 Examples for the Calculation of Voltage Drops 33416.6.1 Example 1: Calculation of Voltage Drop for a DC System 33416.6.2 Example 2: Calculation of Voltage Drop for an AC System 33516.6.3 Voltage Drop for a Three-Phase System 33616.6.4 Example 4: Calculation of Voltage Drop for a Distributor 33816.6.5 Calculation of Cross Section According to Voltage Drop 33816.6.6 Example 6: Calculation of Voltage Drop for an Industrial Plant 33916.6.7 Example 7: Calculation of Voltage Drop for an Electrical Outlet 33916.6.8 Example 8: Calculation of Voltage Drop for a HotWater Storage Unit 33916.6.9 Example 9: Calculation of Voltage Drop for a Pump Facility 33916.6.10 Example: Calculation of Line Parameters 34017 Switchgear Combinations 34317.1 Terms and Definitions 34317.2 Design of the Switchgear 34717.2.1 Data for Design 34717.2.2 Design of the Distributor and Proof of Construction 34817.2.3 Short-Circuit Resistance Proofing 34817.2.4 Proof of Heating 34917.2.5 Determination of an Operating Current 34917.2.6 Determination of Power Losses 35017.2.7 Determination of a Design Loading Factor RDF 35017.2.8 Determination of an Operating Current 35017.2.9 Check of Short-Circuit Variables 35117.2.10 Construction and Manufacturing of the Distribution 35117.2.11 CE Conformity 35217.3 Proof of Observance of Boundary Overtemperatures 35217.4 Power Losses 35318 Compensation for Reactive Power 35518.1 Terms and Definitions 35518.2 Effect of Reactive Power 35818.3 Compensation for Transformers 35818.4 Compensation for Asynchronous Motors 35918.5 Compensation for Discharge Lamps 35918.6 c∕k Value 36018.7 Resonant Circuits 36018.8 Harmonics and Voltage Quality 36018.8.1 CompensationWith Nonchoked Capacitors 36218.8.2 Inductor–Capacitor Units 36318.8.3 Series Resonant Filter Circuits 36518.9 Static Compensation for Reactive Power 36518.9.1 Planning of Compensation Systems 36818.10 Examples of Compensation for Reactive Power 36818.10.1 Example 1: Determination of Capacitive Power 36818.10.2 Example 2: Capacitive Power With k Factor 36918.10.3 Example 3: Determination of Cable Cross Section 36918.10.4 Example 4: Calculation of the c∕k Value 37019 Lightning Protection Systems 37119.1 Lightning Protection Class 37319.2 Exterior Lightning Protection 37419.2.1 Air Terminal 37419.2.2 Down Conductors 37519.2.3 Grounding Systems 37919.2.3.1 Minimum Length of Ground Electrodes 38519.2.4 Example 1: Calculation of Grounding Resistances 38619.2.5 Example 2: Minimum Lengths of Grounding Electrodes 38719.2.6 Exposure Distances in theWall Area 38719.2.7 Grounding of Antenna Systems 38919.2.8 Examples of Installations 38919.3 Interior Lightning Protection 39219.3.1 The EMC Lightning Protection Zone Concept 39219.3.2 Planning Data for Lightning Protection Systems 39520 Lighting Systems 39920.1 Interior Lighting 39920.1.1 Terms and Definitions 39920.2 Types of Lighting 40020.2.1 Normal Lighting 40020.2.2 Normal Workplace-Oriented Lighting 40020.2.3 Localized Lighting 40020.2.4 Technical Requirements for Lighting 40120.2.5 Selection and Installation of Operational Equipment 40120.2.6 Lighting Circuits for Special Rooms and Systems 40220.3 Lighting Calculations 40320.4 Planning of Lighting with Data Blocks 40520.4.1 System Power 40520.4.2 Distribution of Luminous Intensity 40520.4.3 Luminous Flux Distribution 40520.4.4 Efficiencies 40620.4.5 Spacing Between Lighting Elements 40720.4.6 Number of Fluorescent Lamps in a Room 40720.4.7 Illuminance Distribution Curves 40720.4.8 Maximum Number of Fluorescent Lamps on Switches 40720.4.9 Maximum Number of Discharge Lamps Per Circuit-Breaker 40820.4.10 Mark of Origin 40820.4.11 Standard Values for Planning Lighting Systems 40920.4.12 Economic Analysis and Costs of Lighting 40920.5 Procedure for Project Planning 41220.6 Exterior Lighting 41320.7 Low-Voltage Halogen Lamps 41520.8 Safety and Standby Lighting 41620.8.1 Terms and Definitions 41620.8.2 Circuits 41720.8.3 Structural Types for Groups of People 41720.8.4 Planning and Configuring of Emergency Symbol and Safety Lighting 41720.8.5 Power Supply 42120.8.6 Notes on Installation 42220.8.7 Testing During Operation 42220.9 Battery Systems 42320.9.1 Central Battery Systems 42320.9.2 Grouped Battery Systems 42720.9.3 Single Battery Systems 42920.9.4 Example: Dimensioning of Safety and Standby Lighting 43221 Generators 43521.1 Generators in Network Operation 43721.2 Connecting Parallel to the Network 43821.3 Consideration of Power and Torque 43821.4 Power Diagram of a Turbo Generator 43921.5 Example 1: Polar Wheel Angle Calculation 44021.6 Example 2: Calculation of the Power Diagram 44022 Transformer 44122.1 Introduction 44122.2 Core 44522.3 Winding 44622.4 Constructions 44622.5 AC Transformer 44622.5.1 Construction 44622.5.2 Mode of Action 44722.5.3 Idling Stress 44822.5.4 Voltage and Current Translation 44822.5.5 Operating Behavior of the Transformer 44922.6 Three-phase Transformer 45222.6.1 Construction 45222.6.2 Windings 45222.6.3 Circuit Groups 45222.6.4 Overview of Vector Groups 45422.6.5 Parallel Connection of Transformers 45422.7 Transformers for Measuring Purposes 45722.7.1 Current Transformers 45722.7.2 Voltage Transformer 45722.7.3 Frequency Transformer 45822.8 Transformer Efficiency 45922.9 Protection of Transformers 45922.10 Selection of Transformers 45922.11 Calculation of a Continuous Short-Circuit Current on the NS Side of a Transformer 46122.12 Examples of Transformers 46222.12.1 Example 1: Calculation of the Continuous Short-Circuit Current 46222.12.2 Example: Calculation of a Three-phase Transformer 46223 Asynchronous Motors 46723.1 Designs and Types 46723.1.1 Principle of Operation (No-Load) 46823.1.1.1 Motor Behavior 46923.1.1.2 Generator Behavior 46923.1.2 Typical Speed–Torque Characteristics 46923.2 Properties Characterizing Asynchronous Motors 47123.2.1 Rotor Frequency 47123.2.2 Torque 47123.2.3 Slip 47223.2.4 Gear System 47223.3 Startup of Asynchronous Motors 47323.3.1 Direct Switch-On 47323.3.2 Star Delta Startup 47423.4 Speed Adjustment 47923.4.1 Speed Control by the Slip 47923.4.2 Speed Control by Frequency 47923.4.3 Speed Control by Pole Changing 48023.4.4 Soft Starters 48123.4.5 Example: Calculation of Overload and Starting Conditions 48323.4.6 Example: Calculation of Motor Data 48423.4.7 Example: Calculation of the Belt Pulley Diameter and Motor Power 48523.4.8 Example: Dimensioning of a Motor 48524 Questions About Book 48724.1 Characteristics of Electrical Cables 48724.2 Dimensioning of Electric Cables 48724.3 Voltage Drop and Power Loss 48824.4 Protective Measures and Earthing in the Low-voltage Power Systems 48824.5 Short Circuit Calculation 48824.6 Switchgear 48924.7 Protection Devices 48924.8 Electric Machines 489References 491Index 495