Protection of Electricity Distribution Networks

• Autore: Gers Juan M
• Pubblicazione: Stevenage : , : Institution of Engineering & Technology, , 2022; ©2022
• Edizione: 4th ed.
• Descrizione fisica: 1 online resource (548 pages)
• Disciplina: 621.319
• Soggetto topico: Electric power distribution
• Altri autori: HolmesEdward
• Nota di contenuto: Intro -- Title -- Copyright -- Contents -- About the authors -- Preface and acknowledgements -- Preface to second edition -- Preface to third edition -- 1 Introduction -- 1.1 General -- 1.2 Basic principles of electrical systems -- 1.3 Protection requirements -- 1.4 Protection zones -- 1.5 Primary and backup protection -- 1.5.1 Primary protection -- 1.5.2 Backup protection -- 1.6 Directional protection -- 1.7 Relay models -- 1.8 Adaptive protection -- 2 Calculation of short circuit currents -- 2.1 Modelling for short circuit current calculations -- 2.1.1 Effect of the system impedance -- 2.1.2 Effect of rotating machinery -- 2.1.3 Types of fault duty -- 2.1.4 Calculation of fault duty values -- 2.2 Fault calculation for symmetrical faults -- 2.3 Symmetrical components -- 2.3.1 Importance and construction of sequence networks -- 2.3.2 Calculation of asymmetrical faults using symmetrical components -- 2.3.3 Equivalent impedances for a power system -- 2.4 Supplying the current and voltage signals to protection systems -- 2.5 General considerations of fault currents from DERs -- 2.6 Analysis tools for short circuit current calculation -- 3 Classification and function of relays -- 3.1 Classification -- 3.1.1 Construction -- 3.1.2 Incoming signal -- 3.1.3 Function -- 3.1.4 International identification of electrical devices -- 3.2 Electromechanical relays -- 3.2.1 Attraction relays -- 3.2.2 Relays with moveable coils -- 3.2.3 Induction relays -- 3.3 Evolution of protection relays -- 3.4 Numerical protection -- 3.4.1 General -- 3.4.2 Characteristics of numerical relays -- 3.4.3 Typical architectures of numerical relays -- 3.4.4 Standard functions of numerical relays -- 3.5 Supplies to the relay circuits -- 4 Current and voltage transformers -- 4.1 Voltage transformers -- 4.1.1 Equivalent circuit -- 4.1.2 Errors -- 4.1.3 Burden -- 4.1.4 Selection of VTs. ; 4.1.5 Capacitor VTs -- 4.2 Current transformers -- 4.2.1 Equivalent circuit -- 4.2.2 Errors -- 4.2.3 AC saturation -- 4.2.4 Burden -- 4.2.5 Selection of CTs -- 4.2.6 Accuracy classes established by the ANSI standards -- 4.2.7 DC saturation -- 4.2.8 Precautions when working with CTs -- 5 Overcurrent protection -- 5.1 General -- 5.2 Types of overcurrent relay -- 5.2.1 Definite-current relays -- 5.2.2 Definite-time/current or definite-time relay -- 5.2.3 Inverse-time relays -- 5.3 Setting overcurrent relays -- 5.3.1 Setting instantaneous units -- 5.3.2 Coverage of instantaneous units protecting lines between substations -- 5.3.3 Setting the parameters of time-delay overcurrent relays -- 5.4 Constraints of relay coordination -- 5.4.1 Minimum short circuit levels -- 5.4.2 Thermal limits -- 5.4.3 Pickup values -- 5.5 Coordination across Dy transformers -- 5.5.1 Three-phase fault -- 5.5.2 Phase-to-phase fault -- 5.5.3 Phase-to-earth fault -- 5.6 Coordination with fuses -- 5.7 Coordination of negative-sequence units -- 5.8 Overcurrent relays with voltage control -- 5.9 Setting overcurrent relays using software techniques -- 5.10 Use of digital logic in numerical relaying -- 5.10.1 General -- 5.10.2 Principles of digital logic -- 5.10.3 Logic schemes -- 5.11 Adaptive protection with group settings change -- 5.12 Exercises -- 6 Fuses, reclosers and sectionalisers -- 6.1 Equipment -- 6.1.1 Reclosers -- 6.1.2 Sectionalisers -- 6.1.3 Fuses -- 6.2 Criteria for coordination of time/current devices in distribution systems -- 6.2.1 Fuse-fuse coordination -- 6.2.2 Recloser-fuse coordination -- 6.2.3 Recloser-recloser coordination -- 6.2.4 Recloser-relay coordination -- 6.2.5 Recloser-sectionaliser coordination -- 6.2.6 Recloser-sectionaliser-fuse coordination -- 6.2.7 Current-limiting fuses. ; 6.3 Criteria for coordination of time/current devices under automated feeder reconfiguration -- 6.4 Criteria for coordination of time/current devices with DG intermittent sources -- 7 Directional overcurrent relays -- 7.1 Construction -- 7.2 Principle of operation -- 7.3 Relay connections -- 7.3.1 30° Connection (0° AMT) -- 7.3.2 60° Connection (0° AMT) -- 7.3.3 90° Connection (30° AMT) -- 7.3.4 90 Connection (45 AMT) -- 7.4 Directional earth-fault relays -- 7.5 Coordination of instantaneous units -- 7.6 Setting of time-delay directional overcurrent units -- 7.6.1 Pickup setting -- 7.6.2 Time dial setting -- 7.7 Importance of the directional protection -- 7.8 Exercises -- 8 Differential protection -- 8.1 General -- 8.2 Classification of differential protection -- 8.3 Transformer differential protection -- 8.3.1 Basic considerations -- 8.3.2 Selection and connection of CTs -- 8.3.3 Inrush restraint -- 8.3.4 Percentage of winding protected by the differential relay during an earth fault -- 8.3.5 Determination of the slope -- 8.3.6 Distribution of fault current in power transformers -- 8.3.7 Dual slope setting -- 8.3.8 Overexcitation (V/Hz) -- 8.3.9 High setting (this defeats the differential protection) -- 8.4 Differential protection for generators and rotating machines -- 8.5 Line differential protection -- 8.6 Busbar differential protection -- 8.6.1 Differential system with multiple restraint -- 8.6.2 High-impedance differential system -- 8.7 Exercises -- 9 Distance protection -- 9.1 General -- 9.2 Types of distance relays -- 9.2.1 Impedance relay -- 9.2.2 Directional relay -- 9.2.3 Reactance relay -- 9.2.4 Mho relay -- 9.2.5 Completely polarised mho relay -- 9.2.6 Relays with lens characteristics -- 9.2.7 Relays with polygonal characteristics -- 9.2.8 Relays with combined characteristics -- 9.3 Setting the reach and operating time of distance relays. ; 9.4 The effect of infeeds on distance relays -- 9.5 The effect of arc resistance on distance protection -- 9.6 Residual compensation -- 9.7 Impedances seen by distance relays -- 9.7.1 Phase units -- 9.7.2 Earth-fault units -- 9.8 Power system oscillations -- 9.9 The effective cover of distance relays -- 9.10 Maximum load check -- 9.10.1 Mho relays -- 9.10.2 Relays with a polygonal characteristic -- 9.11 Drawing relay settings -- 9.11.1 Starting unit settings -- 9.11.2 Residual compensation constant setting -- 9.11.3 Time setting -- 9.11.4 Load check -- 9.11.5 Determination of the effective cover -- 9.12 Intertripping schemes -- 9.12.1 Underreach with direct tripping -- 9.12.2 Permissive underreach intertripping -- 9.12.3 Permissive overreach intertripping -- 9.13 Distance relays on series-compensated lines -- 9.14 Technical considerations of distance protection in tee circuits -- 9.14.1 Tee connection with infeeds at two terminals -- 9.14.2 Tee connection with infeeds at all three terminals -- 9.15 Use of distance relays for the detection of the loss of excitation in generators -- 9.16 Exercises -- 10 Protection of low-voltage systems -- 10.1 Protection devices -- 10.1.1 Overcurrent relays -- 10.1.2 Direct-acting devices in power breakers and MCCBs -- 10.1.3 Combined thermal relay contactor and fuse -- 10.1.4 MCCBs with numerical protection -- 10.2 Criteria for setting overcurrent protection devices associated with motors -- 10.2.1 Thermal relays -- 10.2.2 Low-voltage breakers -- 10.3 Arc flash -- 10.3.1 Arc flash calculation methods -- 10.3.2 Arc flash and approach boundary -- 10.3.3 Hazard study methodology -- 10.3.4 Electrode configurations -- 10.3.5 Selection of PPE -- 10.3.6 Arc thermal performance value -- 10.3.7 Energy break-open threshold -- 10.3.8 DC arc flash calculations -- 11 Industrial plant load shedding. ; 11.1 Power system operation after loss of generation -- 11.2 Design of an automatic load shedding system -- 11.2.1 Simple machine model -- 11.2.2 Considerations of implementing a load shedding system -- 11.3 Criteria for setting frequency relays -- 11.3.1 Operating times -- 11.3.2 Determination of the frequency variation -- 11.4 Example of calculating and setting frequency relays in an industrial plant -- 11.4.1 Calculation of overload -- 11.4.2 Load to be shed -- 11.4.3 Frequency levels -- 11.4.4 Load shedding stages -- 11.4.5 Determination of the frequency relay settings -- 11.4.6 Verification of operation -- 11.5 Load shedding using logic schemes -- 12 Protection schemes and substation design diagrams -- 12.1 Protection schemes -- 12.1.1 Generator protection -- 12.1.2 Motor protection -- 12.1.3 Transformer protection -- 12.1.4 Line protection -- 12.2 Types of substations -- 12.3 Substation design diagrams -- 12.3.1 Single-line diagrams -- 12.3.2 Substation layout diagrams -- 12.3.3 Diagrams of AC connections -- 12.3.4 Diagrams of DC connections -- 12.3.5 Wiring diagrams -- 12.3.6 Digital substations -- 12.3.7 Logic diagrams -- 12.3.8 Cabling lists -- 13 Communication networks for power systems automation -- 13.1 IEC 61850 overview -- 13.2 Standard documents and features of IEC 61850 -- 13.3 System Configuration Language -- 13.4 Challenges facing the testing of IEC 61850 devices -- 13.5 Configuration and verification of GOOSE messages -- 13.5.1 Configuration of the system -- 13.5.2 System verification test -- 13.6 Substation IT network -- 13.7 Process bus -- 14 Installation, testing and maintenance of protection systems -- 14.1 Installation of protection equipment -- 14.2 Testing protection schemes -- 14.2.1 Factory acceptance test -- 14.2.2 Commissioning tests -- 14.2.3 Maintenance test -- 14.2.4 Troubleshooting. ; 14.3 Commissioning numerical protection.
• Sommario/riassunto: This book provides an overview of most aspects of electrical protections. The emphasis is on distribution systems, but protection of generation and transmission systems are also treated. For this 4th edition, new topics are added, such as protection of renewable power plants and transient stability analysis.
• Titolo autorizzato: Protection of Electricity Distribution Networks
• ISBN: 1-83724-570-3; 1-5231-4232-4; 1-83953-271-8
• Formato: Materiale a stampa
• Livello bibliografico: Monografia
• Lingua di pubblicazione: Inglese
• Record Nr.: 9911006701203321
• Lo trovi qui: Univ. Federico II
• Serie: Energy Engineering