Electricity distribution network design

Transcription

1 Electricity distribution network design 2nd E. Lakervi and E. J. Holmes Peter Peregrinus Ltd., on behalf of The Institution of Electrica! Engineers

2 Contents Pai> Preface and acknowledgements Preface to the 2nd edition xi xii 1 The supply System Generation, transmission & distribution Supply Organisation» The distribution System Supply requirements Network configurations Auxiliary Systems 17 2 Planning distribution networks Overall philosophy Planning objeetives Combiniitg engineering and ecünomics Eiltet of the existing network Consideration of devclopmem trends Produelion of long-term plans Bibliography 25 3 Technical considerations General Modcliing network eoinponcnts Coinponenti Transforming impedanees Per-unit values Power flows and losses Power llows Power losses Load and loss load factors Heating eiltet Voltage drop 38

3 Contents 3.5 System earlhing General Hazard voltages Neutral earthing arrangements Direct earthing Impedance earthing Arc-suppresiion-coil earthing Isolated neutral Systems Low-\ : oltage-sysu'm proteciive earlhing 3.6 Fault calculations 3.7 L'nsymmetrical faults Sequence networks System sequence impedanees F.artli faults 3.8 Overvoltages 3.9 Bibliography Reliability 4.1 General 4.2 Reliability Investment appraisal 4.3 Basic reliability theoiy Comporients Radially operated Systems Parallel or mesh Systems 4.4 Reliability calculation examplc 4.5 Bibliography Economic priilciples 5.1 Iniroduetion 5.2 I'resent worth 5.3 Discounled eash flow 5.4 Time seale of st.udies and residual valucs 5.5 Inflation and iiuercsi rates 5.6 Scnsitivttv analvsis 5.7 System losses 5.8 Other Factors 5.9 Bibliography Equipment 6.1 General 6.2 TransForrncrs General Losses Insnlation life Reaetanee of large supply transformers UnsyrnnU'tiieal loads 6.3 Overhcad lines 6.4 Underground cables 6.5 Switchgear Tntroduction Circuit breakers Disconucctors 6.6 ReplaccmenL oi equipment 6.7 Bibliography

4 Contents vu 7 System protection General ' Overcurrent protection Ftises Overcurrent relays Earth-faull protection ' Unit and dist.ariee protection Unit protection Distance protection 13 J 7.5 Autoredosing arrangement Overvoltage protection Automation of network Operation Distribution managemenl Systems Bibliograph) '"*J 8 HV networks and substations General 1 1B 8.2 HV networks Substation Arrangements läl Site location Design philosophy '^ Mesh-typc substations Single- and double-busbar arrangements MV busbar arrangements Auxiliary Systems General Transformer protection Busbar protection Auxiliary supplies Bibliograph)' '6 ;i 9 MV networks 9.1 General Choice of network voltage System modelling Principles for determining cireuit dimensions 1 / Example: Choice of c:onductor size for a nevv line on an economic basis Example: Choice of conductor size to replace an existing conductor ' ' Operational aspects 1^ Network arrangements Load-transfer schemes 1S Optimum location of protective equiprnenl and switching devices ' Network reinforcements 18" 9.6 Bibliograph) Distribution substations and LV networks General 192 _ 10.2 Cable-connected substations 19-i 10.3 Pole-mounted substations I.V nelwork arrangements ' Service conneclions Bibliograph)

5 viii Contents 11 Load data 11.1 Demands for dcsign 11.2 Load-monitoring measurcments 11.3 Load analysis and synthesis Load foitcasting 11.5 Short-term load forecasts 11.6 Bibliography 12 Special loads 12.1 General 12.2 Electric-arc furtiaccs I.oad cliaracteristics: Voltage fluctuations and lamp Dicker Melhods Tor rrducing voltage fluctuation l.oading cycles and transformer losses 12.3 Convertors 12.4 Motors Starting currenis Voltage variations Short-circuit contribution Examplc of effeet of niotor loads on System 12.5 Raifway traction 12.6 Oüicr loads Wclding cquipment Induction heating equipment Miscellaneous loads 12.7 Elcclromagnetir compatibility Iiitcniatiotial regulations Voltage characlcristics Measurement of voltage cliaracteristics 12.8 Bibliograph) 13 Network voltage Performance 13.1 General 13.2 Voltage rcgulation 13.3 Automatic voltage control 13.4 Line-drop compensation 13.5 Distribution-translbrmer tap sellings 13.6 Regulators and capacitors 13.7 Integration of voltage-control facilities 13.8 Voltage unbalance 13.9 Constraints afferting network-voltage Performance Guslomer-voltage fluctuations Harmonics Bibliography 14 Computer-based planning 14.1 General 14.2 Network Information Systems General Development phases Information System eomponents Network databases

6 Databasf maiiagemerit Application programs 14.3 Xdwork calculations 14.4 Mathematical methods for network plannin 14.5 Examples of applicatums Example Example Planning example Data and targets Present Situation Demand forecasts Development alternatives Substation optimisation 14.7 Bibliograpliy 15 Co-operation in network planning and design 15.1 General 15.2 Town and eountry planning 15.3 Co-operation with otlicr organisations 15.4 Amenity malters 15.5 Mamifacturers and Consultants 15.6 Universities and rcseareh centres 15.7 Bibliograpliy Index