Overhead Power Lines

by Kiessling, Friedrich; Nefzger, Peter; Nefzger, P.; Nolasco, J. F.; Kaintzyk, U.

• ISBN13: 9783540002970
• ISBN10: 3540002979
• Format: Hardcover
• Copyright: 2003-04-01
• Publisher: Springer Verlag

Summary

Overhead Power Lines presents not only the scientific and engineering basis for the electric and mechanical design, but also comprehensively describes all aspects of most recent technology, including the selection and design of components such as conductors, insulators, fittings, supports and foundations. The chapters on line survey, construction and maintenance address updated requirements and solutions. Reflecting the changing economic and technical environment of the industry, this publication introduces beginners to the full range of relevant topics of line design and implementation and serves as a valuable reference to engineers and technicians employed by overhead line operators, contractors and consulting companies. This first English-language edition, based on the 5 th German-language edition, incorporates the latest international standards, edited by IEC, CENELEC, Cigr??, the International Council of Large Electric Systems, in which the authors have long participated in, and contributed to.

Table of Contents

Overall planning	1	(24)
Symbols	1	(1)
Development stages of a transmission project	1	(1)
Transmission planning	2	(1)
Objective	2	(1)
Planning stages	2	(1)
Planning aspects regarding transmission lines	3	(1)
Planning methods	3	(1)
Data acquisition and preparation	3	(1)
Formulation and preselection of alternatives	4	(1)
Electrical studies	4	(1)
Economic studies and final evaluation	4	(1)
Planning criteria	4	(1)
General	4	(1)
Criteria for steady-ste conditions	5	(1)
Criteria for temporary and transient conditions	5	(1)
Evolution and selection of voltage levels	5	(3)
Evolution of transmission voltages	5	(1)
Introduction of transmission voltages	6	(2)
Conductor selection	8	(1)
Selection of line configuration	9	(3)
Direct current transmission	12	(2)
Aspects of DC transmission components	12	(1)
Economic comparison of DC and AC lines	12	(1)
Technical comparison of AC and DC transmission	13	(1)
Practical use of DC transmission	13	(1)
Transmission with higher order phase lines	14	(2)
Options	14	(1)
Properties of multiple-phase systems	15	(1)
Present experience	15	(1)
Investments	16	(1)
Licences and permit procedures	17	(1)
Underground transmission versus overhead lines	18	(3)
Application and planning aspects	18	(1)
Environmental constraints	19	(1)
Technical limitations	19	(1)
Comparative investments	19	(1)
Perspectives	20	(1)
Results of overall planning	21	(1)
References	22	(3)
Electric requirements and design	25	(54)
Symbols	25	(3)
Overhead lines as components of electric systems	28	(4)
Surge impedance and surge impedance load (natural power)	28	(1)
Stability	29	(1)
Voltage regulation and maximum permissible losses	30	(1)
Capability of a line	30	(1)
Reliability and availability	30	(1)
Reactive power compensation	31	(1)
Power transmitted versus right-of-way width	32	(1)
Current-related phenomena	32	(1)
Normal and emergency conditions	32	(1)
Ohmic losses	32	(1)
Short circuit condition	33	(1)
Voltage and current-related phenomena	33	(10)
Introduction	33	(1)
Electrical and magnetic fields	33	(1)
Effects on humans and animals	33	(3)
Effects on electronic devices	36	(1)
Corona phenomena and related effects	36	(1)
General	36	(1)
Calculation of voltage gradients on individual conductors	36	(1)
Calculation of voltage gradient by approximate formulae	37	(2)
Radio noise or radio interference (RI)	39	(1)
Audible noise (AN)	40	(2)
Impact of line design on voltage- and current-depending phenomena	42	(1)
Line performance and insulation requirements	43	(8)
Introduction	43	(1)
Power frequency voltages and temporary overvoltages	43	(3)
Slow-front overvoltages	46	(1)
Fast-front overvoltages	46	(1)
Principles of insulation coordination	46	(1)
General principles	46	(1)
Insulation design for permanent power frequency voltages	47	(1)
Insulation design for slow-front overvoltages	47	(3)
Insulation design for fast-front overvoltage	50	(1)
Live-line maintenance	51	(1)
Clearances	51	(24)
Clearance requirements	51	(1)
Types of electrical clearances	51	(1)
Calculation of electrical clearances	52	(1)
Required withstand voltages of air gaps	52	(2)
Voltages to be considered	54	(2)
Summary of formulae for electrical clearances	56	(1)
Empirical data for clearances	57	(1)
Internal and external clearances	58	(1)
Introduction	58	(1)
Design principles	58	(1)
Load cases for the calculation of clearances	59	(1)
Maximum conductor temperature at no-wind condition	59	(1)
Ice load without wind	59	(1)
Wind load assumptions	60	(1)
Insulator and conductor position under wind action	61	(1)
Definition of wind action	61	(2)
Calculation of swing angle	63	(1)
Time distribution of swing angles	64	(1)
Determination of swing angles by measurements	65	(1)
Conductor and insulator position according to standards	65	(1)
Midspan clearances	65	(2)
Minimum clearances within a span or at a tower	67	(1)
Clearances to ground and obstacles	67	(1)
Examples	67	(1)
Electrical clearances for a 110 kV overhead line	67	(2)
Electrical clearances for a 380 kV overhead line	69	(1)
Electrical clearances for a 500 kV overhead line	70	(1)
Clearances to obstacles for line design, empirical approach	71	(1)
Time distribution of swing angles	72	(1)
Tower top geometry according to statistic considerations	73	(1)
Tower top geometry according to European standards	74	(1)
Tower top geometry according to Brazilian practice	74	(1)
References	75	(4)
Electric parameters	79	(20)
Symbols	79	(1)
Introduction	80	(1)
Resistance	81	(1)
Positive-sequence impedance	81	(4)
Introduction	81	(1)
Inductance and inductive Reactance	82	(3)
Zero-sequence impedance	85	(3)
Introduction	85	(1)
Simplified approach for the determination of zero-sequence impedances	85	(3)
Capacitance and capacitive reactance	88	(3)
General considerations	88	(1)
Single-circuit lines	89	(1)
Double-circuit lines	90	(1)
Admittance	91	(1)
Electric representation of lines	92	(5)
Goals and basic conditions	92	(1)
Short- and medium-length lines	92	(1)
Long-length transmission lines	93	(1)
Representation by exponential functions	93	(1)
Representation by hyperbolic functions	94	(1)
The equivalent II-circuit of a long line	95	(2)
References	97	(2)
Lightning protection	99	(16)
Symbols	99	(1)
Significance of lightning	99	(1)
Formation of lightning strokes	100	(2)
Mechanism of lightning discharge	100	(1)
Impulse behaviour of lightning discharges	100	(1)
Electric characteristics of the discharges	101	(1)
Frequency and intensity of lightning strokes	102	(4)
Keraunic levels and earth flash density	102	(2)
Magnitude of lightning stroke currents	104	(1)
Direct and indirect lightning strokes	105	(1)
Arrangement and efficiency of earth wires	106	(4)
Theoretical background	106	(1)
Effective shielding by earth wires	107	(3)
Surge arresters	110	(1)
Assessment of lightning performance of overhead lines	110	(1)
Earthing in view of lightning protection	110	(2)
Significance of earthing for lightning protection	110	(1)
Surge impedance of earthing systems	111	(1)
References	112	(3)
Earthing	115	(28)
Symbols	115	(1)
Purpose of earthing	116	(1)
Definitions and basic principles	117	(1)
Requirements	118	(3)
Standards	118	(1)
Safety of persons	118	(1)
Thermal short-circuit strength	119	(1)
Mechanical strength and corrosion resistance	119	(1)
Currents to be considered	120	(1)
Earthing for personal safety purposes	121	(3)
Operational earthing	124	(1)
Lightning protection earthing	124	(1)
Rating for short-term currents	125	(1)
Soil resistivity and conductivity	125	(1)
Calculation of earthing resistance	126	(4)
Spherical electrode	126	(1)
Earthing rods	127	(2)
Horizontally arranged electrode wires (counterpoises)	129	(1)
Measurements of soil resistivity	130	(2)
Basic principles	130	(1)
Measuring methods	131	(1)
Measurement of earthing resistance	132	(3)
Earthing resistance in non-homogeneous soils	135	(4)
Soil resistivity in a two-layer soil structure	135	(1)
Computation of earthing resistance in a two-layer soil structure	136	(2)
Computation of earthing resistance by means of the apparent resistivity	138	(1)
Computation of earthing resistance of three-dimensional structures	138	(1)
Example for computation of earthing resistance	139	(1)
Practical rules for installation of earthing systems	139	(1)
Radial and ring-type earthing counterpoises	139	(1)
Vertically or obliquely driven earthing rods	140	(1)
Bonding between earthing electrodes	140	(1)
Earthing connections	140	(1)
References	140	(3)
Requirements on loading and strength	143	(52)
Symbols	143	(2)
Mechanical design of the overhead line system	145	(11)
Components and elements of an overhead line	145	(1)
Reliability	145	(1)
Calculation of reliability	146	(4)
Strength coordination and selection of reliability	150	(2)
Effect of maximum load intensity on a high number of components	152	(2)
Use factor and its effect on the design	154	(2)
Strength of line components and elements	156	(2)
Strength limits	156	(1)
Rating of individual components and elements	157	(1)
Damage and failure limits	158	(1)
Wind loads	158	(7)
Wind measurements	158	(1)
Determination of meteorological reference wind velocities	159	(1)
Evaluation of wind measurements	159	(3)
Effect of the terrain roughness	162	(1)
Variation of reference wind velocity with height	163	(1)
Wind action on line components and elements	163	(2)
Ice loads	165	(4)
Atmospheric icing	165	(2)
Ice observations and measurements	167	(1)
Determination of reference ice loads	168	(1)
Basic relations	168	(1)
Evaluation of ice load information	168	(1)
Reference ice load	168	(1)
Loading of supports and load cases	169	(1)
Combined wind and ice loads	169	(3)
Probability of occurrence and combination of parameters	169	(1)
Determination of design parameters	170	(1)
Ice load	170	(1)
Wind load	170	(1)
Effective drag factors and ice densities	171	(1)
Wind action on the ice covered conductor	171	(1)
Climatic loads according to relevant standards	172	(13)
Standards for overhead power lines	172	(1)
Wind loads	172	(1)
Wind load model according to IEC 60826	172	(2)
Wind model according to the European standard EN 50341-1	174	(2)
Wind models according to EN 50341-3	176	(3)
Comparison of wind load models with measurements	179	(2)
Ice loads	181	(1)
Ice load model according to IEC 60826	181	(1)
Ice load model according to EN 50341-1	182	(1)
Ice load model according to EN 50341-3	183	(1)
Combined wind and ice action	183	(1)
Model according to IEC 60826	183	(1)
Model according to EN 50341-1	184	(1)
Combined wind and ice action according to EN 50341-3	184	(1)
Loads at construction, operation and maintenance	185	(2)
Introduction	185	(1)
Requirements according to IEC 60826	186	(1)
Requirements according to EN 50341-1 and EN 50341-3	186	(1)
Failure containment and other special loads	187	(1)
Introduction	187	(1)
Provisions according to IEC 60826	187	(1)
Provisions according to EN 50341-1	187	(1)
Statistical distributions	188	(4)
Introduction	188	(1)
Normal distribution (Gaussian distribution)	188	(2)
Log-normal distribution	190	(1)
Gumbel distribution	190	(2)
References	192	(3)
Selection of conductors	195	(48)
Symbols	195	(1)
Conductor types and design	196	(27)
Introduction	196	(2)
Conductor designation	198	(1)
Progress in technical development	198	(2)
Materials	200	(1)
Aluminium	200	(1)
Aluminium-magnesium-silicon alloys	201	(1)
Steel wires	202	(1)
Aluminium-clad steel wires	202	(1)
Copper and copper alloys	202	(1)
Thermal resistant aluminium alloys	202	(1)
Wire testing	203	(1)
Introduction	203	(1)
Dimensions and surfaces	203	(1)
Testing the tensile strength	203	(1)
Wrapping and twisting test	204	(1)
Testing zinc mass, cladding thickness and uniformity	204	(1)
Testing resistivity	204	(1)
Conductors made of wires with the same material	204	(1)
All aluminium conductors	204	(1)
All aluminium alloy conductors	205	(1)
Aluminium-clad steel conductors	206	(1)
Copper, copper alloy and steel conductors	206	(1)
Composite conductors	206	(1)
Configuration and design	206	(2)
Characteristic data	208	(3)
Production	211	(1)
Joints	212	(1)
Shipment	213	(1)
Conductor testing	213	(1)
Classification of tests	213	(1)
Extent of sample tests	213	(1)
Surface condition, dimensions, inertness and mass	214	(1)
Stress-strain diagram	214	(1)
Tensile breaking strength	215	(1)
Test of creep behaviour	216	(1)
Testing the tension stringing ability of conductors	216	(1)
Bundle conductors	217	(1)
Special conductor designs	218	(1)
Non-standardized conductors made of round wires	218	(1)
Conductors for increased operation temperature	219	(1)
Conductors with enlarged diameters	220	(1)
Conductors with smooth surfaces	221	(1)
Compacted conductors	221	(1)
Self-damping conductors	221	(1)
Vibration resistant conductors	222	(1)
Low noise conductors	222	(1)
Conductors with treated surfaces	223	(1)
Design with regard to current loading	223	(9)
Introduction and requirements	223	(1)
Principles for determination of conductor temperature	224	(1)
Design with regard to current carrying capacity	225	(3)
Design with regard to short-circuit current	228	(1)
Design based on economic considerations	228	(3)
Line capacity as a function of the weather conditions	231	(1)
Design with regard to stresses caused by voltages	232	(2)
Introduction and requirements	232	(1)
Design with respect to the electric parameters	232	(2)
Design with respect to conductor surface gradients and corona effects	234	(1)
Corona losses	234	(1)
Mechanical design of conductors	234	(4)
Introduction and requirements	234	(1)
Stresses under extreme load conditions	235	(1)
Stresses under everyday conditions	236	(1)
Impact of the conductor tensile load on line investment	237	(1)
Conductor creep	238	(1)
Recommendations for selection of conductor tensile stresses	238	(1)
References	238	(5)
Earth wire selection	243	(14)
Symbols	243	(1)
Types of earth wires	243	(1)
Electric and thermal design	244	(6)
Requirements	244	(1)
Earth wire design under short-circuit conditions	244	(3)
Temperature limits of earth wires in case of short circuits	247	(1)
Fault clearing and reclosing operations	247	(1)
Examples of earth wire current carrying capacity in case of short circuits	248	(2)
Mechanical design	250	(1)
Loss of mechanical strength during heating process	250	(1)
Establishing tensile stresses and forces	251	(1)
Steps for selection of conventional earth wires	251	(1)
Earth wires comprising optical fibres (OPGW)	252	(3)
Generalities and design	252	(2)
Installation conditions	254	(1)
Accessories	254	(1)
Tests	255	(1)
References	255	(2)
Insulators	257	(48)
Symbols	257	(1)
Introduction	257	(1)
Ceramic insulators	258	(7)
Insulator types and their application	258	(4)
Raw materials	262	(1)
Production	263	(2)
Glass insulators	265	(2)
Raw materials and production	265	(1)
Insulator types and application	266	(1)
Composite insulators	267	(2)
Raw materials, design and production	267	(1)
Types of composite insulators and their application	268	(1)
Comparison of insulator types	269	(2)
Tests on insulator units	271	(7)
Basic information	271	(1)
Tests on ceramic and glass insulators	271	(1)
Type tests	271	(2)
Sample tests	273	(2)
Routine tests	275	(1)
Tests on composite insulators	276	(1)
Basic information	276	(1)
Test of the structural design and type test	276	(1)
Sample and routine tests	277	(1)
Design of insulator sets	278	(3)
Suspension insulator sets	278	(3)
Tension insulator sets	281	(1)
Requirements for insulator sets	281	(6)
Electric requirements for AC lines	281	(3)
Particularities for DC lines	284	(2)
Audible noise (AN) performance	286	(1)
Mechanical design	287	(1)
Operational performance of insulator strings	287	(8)
Introduction	287	(1)
Voltage stresses	288	(2)
Behaviour of individual insulator types	290	(2)
Behaviour under pollution layers	292	(1)
Formation of pollution layers	292	(1)
Simulation of pollution layers	292	(1)
Pollution levels	293	(1)
Assessment of pollution levels by means of local measurements	293	(1)
Measures to maintain insulation capacity	294	(1)
Testing of insulator sets	295	(2)
Basic information and assumptions	295	(1)
Standard atmospheric conditions	295	(1)
Artificial rain	295	(1)
Testing arrangements	295	(1)
Power frequency voltage test	296	(1)
Fast-front and slow-front overvoltage tests	296	(1)
Power arc behaviour	296	(1)
Radio interference strength test	296	(1)
Corona onset or extinction voltage test	297	(1)
Example for insulator selection	297	(3)
References	300	(5)
Overhead line fittings	305	(16)
Definitions	305	(1)
Fittings for conductors	305	(8)
Conductor attachment at suspension insulator sets	305	(3)
Conductor attachments at dead-end terminations	308	(1)
Turn buckles	309	(1)
Connectors	309	(1)
Spacers for bundle conductors	310	(1)
Vibration dampers for single conductors	311	(1)
Spacer dampers for bundle conductors	312	(1)
Fittings for insulator sets	313	(1)
Rating and tests	313	(4)
General	313	(1)
Electric requirements	313	(1)
Mechanical requirements	314	(1)
Corrosion protection	315	(1)
Selection of material	316	(1)
Tests	316	(1)
References	317	(4)
Conductor vibrations	321	(28)
Symbols	321	(1)
Overview and types of vibration	322	(1)
Aeolian vibrations	323	(17)
Basic physical aspects, mathematic-mechanic model of a line	323	(2)
Conductor free-span amplitude	325	(2)
Conductor strains and stresses	327	(1)
Bending stiffness of a conductor	327	(1)
Origin of vibrations	328	(1)
Consequences of vibrations	329	(3)
Consequences for line design	332	(4)
Verification of vibration intensity and effectiveness of damping measures	336	(2)
Evaluation of vibration measurements	338	(2)
Subspan oscillations	340	(1)
Origin and consequences	340	(1)
Remedy measures	341	(1)
Galloping	341	(3)
Origin and consequences	341	(2)
Remedy measures	343	(1)
Short-circuit oscillations	344	(1)
Origin and consequences	344	(1)
Remedy measures	344	(1)
References	345	(4)
Supports	349	(122)
Symbols	349	(5)
Support types and their applications	354	(7)
Definitions	354	(1)
Tasks of supports in an overhead line	354	(1)
Suspension supports	354	(1)
Angle suspension supports	355	(1)
Angle supports	355	(1)
Strain and angle-strain supports	355	(1)
Dead-end supports	356	(1)
Special supports	356	(1)
Support design and application	356	(1)
Selection of support design	356	(1)
Self-supporting lattice steel towers	357	(1)
Self-supporting steel poles	358	(1)
Steel-reinforced concrete poles	359	(1)
Wood poles	360	(1)
Guyed supports	360	(1)
Crossarmless supports	360	(1)
Tower top geometry	361	(6)
Requirements	361	(1)
Electrical clearances according to relevant standards	361	(1)
Clearance between conductors	361	(1)
Equal cross sections, alike materials and equal sags of conductors	361	(3)
Conductors with different cross sections, materials or sags	364	(1)
Clearances at supports	365	(2)
Basic design requirements	367	(2)
Introduction	367	(1)
Static design	367	(1)
Design values and verification methods	368	(1)
Load cases and partial factors	369	(5)
Combination of loads	369	(1)
Extreme wind load	370	(1)
Wind load at minimum temperature	371	(1)
Uniform and unbalanced ice loads without wind	371	(1)
Combined wind and ice load	372	(1)
Construction and maintenance loads	372	(1)
Security loads	373	(1)
Partial factors for actions on supports	373	(1)
Partial factors for materials	374	(1)
Lattice steel towers	374	(68)
Structural design	374	(1)
Structural design of members	374	(2)
Connections	376	(1)
Walkways	377	(1)
Production	378	(1)
Corrosion protection	378	(1)
Materials	379	(1)
Materials for angle sections and plates	379	(1)
Material for bolts	379	(1)
Analysis of member forces	380	(1)
Calculation of the member forces at a plane system	381	(1)
Basic procedure	381	(1)
Forces in the leg members	381	(1)
Forces in bracings, loaded by horizontal forces	382	(1)
Forces in bracings, loaded by asymmetrical vertical forces	383	(1)
Forces in bracings, loaded by torsional moments	383	(1)
Total forces in bracings	384	(1)
Forces in horizontal members at tower waist	384	(1)
Forces in horizontal bracings within the tower body	385	(1)
Forces in leg extensions	385	(1)
Forces in crossarm members	386	(1)
Analysis of member forces at a three-dimensional system	387	(1)
Basic approach of the finite element method	387	(8)
Application to three-dimensional truss structure systems	395	(1)
Comparison of computations at plane and three-dimensional systems	396	(2)
General format of verification of members and connections	398	(1)
Design of compression members	399	(1)
Effective cross section properties for compression members	399	(1)
Flexural buckling of axially compressed members	399	(7)
Flexural torsional buckling of centrally compressed members	406	(2)
Bending and axial compression forces	408	(1)
Design of compound members	408	(1)
Member connected by batten plates	408	(2)
Laced box-type members	410	(3)
Design of tensile-loaded members	413	(1)
Members axially loaded in tension	413	(2)
Axial tensile force and bending	415	(1)
Design of connections	415	(2)
Design for bending due to transverse loads	417	(1)
Design of redundant members	417	(1)
Deformation	418	(2)
Calculation of foundation loads	420	(1)
Application of computer programs for calculation of lattice steel towers	421	(2)
Upgrading the support strength	423	(2)
Example: Static calculation of a 110 kV suspension support	425	(15)
Example: Calculation guy wire and mast loads in a guyed-V tower	440	(2)
Steel poles	442	(7)
Structural design	442	(1)
Analysis of loads	443	(1)
Rating	444	(3)
Example for design of a conical solid-wall steel pole	447	(2)
Steel-reinforced concrete poles	449	(10)
Selection of cross sections	449	(1)
Spun concrete poles	449	(2)
Vibrated concrete poles	451	(1)
Structural design	451	(1)
Production	451	(1)
Rating	452	(3)
Example for design of a spun concrete pole	455	(1)
Basic data	455	(1)
Calculation of loads	455	(2)
Verification of cross sections	457	(2)
Wood poles	459	(2)
Application and design	459	(1)
Rating	460	(1)
Treatment of wood poles	461	(1)
Loading and failing tests	461	(5)
Introduction	461	(1)
Foundations for support under test	462	(1)
Material for the tower under test	462	(1)
Fabrication of the prototype tower under test	463	(1)
Strain measurements	463	(1)
Assembly and erection	463	(1)
Test loads	463	(1)
Load application	464	(1)
Load procedure	464	(1)
Load measurement	464	(1)
Deflections	464	(1)
Acceptance and failures	465	(1)
Destruction test	465	(1)
Disposition of test tower	465	(1)
Test report	465	(1)
References	466	(5)
Foundations	471	(68)
Symbols	471	(1)
Requirements and preconditions	472	(1)
Types of subsoils	473	(2)
Classification of soil	473	(1)
Undisturbed natural soil	474	(1)
Rock	475	(1)
Filled-up soil	475	(1)
Subsoil investigation	475	(13)
Purpose of subsoil investigation	475	(1)
Methods for obtaining soil samples	476	(1)
Type of samples	476	(1)
Trial pits	476	(1)
Exploratory borings	477	(1)
Soil investigation by drilling probes	478	(1)
Probes	478	(1)
Types of probes	478	(1)
Driven probes	478	(2)
Standard penetration test	480	(1)
Van-type probes	480	(1)
Compression probes	480	(1)
Evaluation of soil investigation	481	(1)
Classification and description of soil types	481	(2)
Classification of rock	483	(2)
Concrete-aggressive water and soils	485	(1)
Borehole log	485	(2)
Graphical representation	487	(1)
Design and calculation of foundations	488	(39)
Type of foundation and load	488	(1)
Soil characteristics	489	(1)
Compact foundations	490	(1)
Definition	490	(1)
Monoblock foundations	491	(1)
Monoblock foundations without base enlargement	492	(2)
Monoblock foundation with base enlargement	494	(1)
Slab foundations	495	(4)
Single grillage foundation	499	(1)
Single pile foundations	499	(3)
Foundation of self-supporting timber poles	502	(1)
Separate foundations	502	(1)
Definition	502	(1)
Stepped block foundations	503	(4)
Auger-bored and excavated foundations	507	(4)
Separate grillage foundations	511	(1)
Pile foundations	512	(7)
Steel reinforced pad and chimney foundation	519	(2)
Foundations in rock	521	(2)
Anchoring of leg member stubs	523	(1)
Foundation for guyed towers	524	(1)
Acting loads	524	(1)
Central footings	524	(1)
Foundations for guy wires	525	(1)
Field tests	526	(1)
Testing of foundations	527	(7)
Definitions and object	527	(1)
Categories of tests	527	(1)
Foundation installation	528	(1)
Testing equipment	528	(1)
Testing procedure	529	(2)
Test evaluation and acceptance criteria	531	(1)
Uplift load tests on construction and test piles	532	(2)
References	534	(5)
Sag and tension calculations	539	(34)
Symbols	539	(1)
Basis	540	(1)
Sags described by the catenary curve	540	(4)
Conductor sagging curve as a parabola	544	(2)
Span with differing attachment levels	546	(1)
Conductor state change equation	546	(3)
Span with concentrated loads	549	(2)
Span with tension insulator sets at both ends	551	(2)
Conductor forces and sags in a tensioning section	553	(10)
Introduction	553	(1)
Conductor state in spans with end points movable in line direction	554	(2)
Conductor stresses and sags in case of inverted V-insulator sets	556	(1)
Conductor state change equation for a tensioning section	557	(5)
Computer program for conductor state change in a tensioning section	562	(1)
Approximate formulae of sags at ice load in one span only	562	(1)
Clearances to ground and to objects	563	(7)
Requirements	563	(1)
Calculation of clearance to ground	564	(1)
Calculation of the clearance to a crossed road	565	(2)
Calculation of clearance to a crossed line	567	(3)
References	570	(3)
Route selection and detailed line design	573	(48)
Symbols	573	(1)
Introduction	573	(2)
Basic information	573	(1)
Preliminary activities	574	(1)
Route selection and licences	575	(20)
Introduction	575	(1)
General aspects and guidelines	575	(2)
Alternative line designs	577	(1)
Conversion of existing lines	577	(1)
Underground transmission	577	(1)
Regulatory controls and permit procedures	578	(1)
Introduction	578	(1)
Permits	578	(1)
Regulations, approvals and procedures	578	(1)
Compensations	579	(1)
Environmental impact assessment	580	(1)
Outline of the process	580	(1)
Environmental impact studies	581	(1)
Existing environmental situation without the line project	581	(2)
Reference alternative	583	(1)
Environmental impacts of a new line	583	(1)
Route selection and line design in view of visual impact	583	(1)
Introduction	583	(1)
Conceptual approaches	584	(1)
Assessment through qualitative methods	584	(1)
Assessment through quantitative methods	584	(1)
Routing for minimum visual impact	585	(2)
Visualization of new lines	587	(1)
Design of components to reduce visual impact	588	(3)
Route selection in view of people	591	(1)
Route selection and line design in view of ecological systems	591	(1)
Introduction	591	(1)
Impacts on avifauna	591	(1)
Impacts on wild animals	592	(1)
Impacts on vegetation	593	(1)
Conservation and wilderness areas	593	(1)
Route selection in view of land use	593	(1)
Introduction	593	(1)
Agricultural areas	593	(1)
Forestry	594	(1)
Industrial areas and infrastructure developments	594	(1)
Urban areas	595	(1)
Survey on site	595	(8)
Steps of survey	595	(1)
Survey procedures and instruments adopted	596	(1)
Direct survey in the terrain	596	(2)
Indirect line survey	598	(2)
Terrain data banks	600	(1)
Survey of angle points and line alignment	600	(1)
Survey of terrain profile	601	(1)
Location of supports	601	(1)
Survey of existing lines	601	(2)
Line design and establishing of plans	603	(8)
Clearances	603	(2)
Determination of support locations, tower types and heights	605	(1)
Evaluation of the profile survey	605	(1)
Basis and relevant parameters	605	(1)
Manual tower spotting	606	(1)
Tower spotting and optimization by means of data processing	607	(3)
Documentation of lines	610	(1)
Data processing for line design and administration	611	(6)
Data processing systems for planning of overhead lines	611	(1)
Establishing the longitudinal profile	611	(3)
Establishing the plan layout	614	(2)
Graphical Information System with integrated data bank	616	(1)
Administration of plans, lists and documents	617	(1)
References	617	(4)
Construction	621	(56)
Symbols	621	(1)
Construction planning	622	(2)
Introduction	622	(1)
Construction time schedule	622	(1)
Mobilisation and stockyard	623	(1)
Transportation	624	(1)
Means of transport	624	(1)
Access roads	625	(1)
Fences, gates and cattle-guards	625	(1)
Construction of foundations	625	(15)
Introduction	625	(1)
Concrete foundations black and slab foundations	625	(1)
Augerbored foundations	626	(1)
Driven pile foundations	627	(1)
Common rules	627	(1)
Steel piles	628	(1)
Steel piles grouted by mortar	628	(1)
Testing	629	(1)
Grillage foundations	629	(1)
Anchor foundations	630	(1)
Concrete for foundations	631	(1)
Ready-mixed and site-mixed concrete	631	(1)
Constituent materials	631	(2)
Requirements on concrete and concrete properties	633	(3)
Ready-mixed concrete	636	(1)
Site-mixed concrete	636	(2)
Handling and placing the concrete	638	(1)
Curing the concrete	638	(1)
Methods for verification of concrete properties	639	(1)
Quality supervision and quality management	639	(1)
Installation of earthing	640	(1)
Setting of tower stubs or bases	641	(4)
Methods and tools	641	(1)
Inclination of angle and dead-end towers	642	(3)
Erection of supports	645	(8)
Introduction	645	(1)
Assembly and erection by elevation	645	(1)
Tower erection using a crane	645	(1)
Tower erection by means of a gin pole	646	(1)
Procedures	646	(1)
Erection with a gin pole outside the tower	646	(1)
Erection with gin pole in the tower centre	647	(1)
Erection with a gin pole in the tower at a leg member	648	(1)
Erection of guyed towers	648	(1)
Hoisting of a crossarm using a gin pole	648	(1)
Tower erection using helicopters	649	(1)
Manual method	650	(1)
Use of an auxiliary mast	650	(1)
Erection by cranes	651	(1)
Bolts and torques	652	(1)
Installation of insulator sets and hardware	653	(1)
Insulator sets	653	(1)
Joints	653	(1)
Conductor stringing	653	(20)
General requirements	653	(1)
Stringing methods	654	(1)
Conductor stringing equipment	655	(1)
Requirements	655	(1)
Pulling ropes	655	(1)
Rope connections	656	(1)
Stringing blocks	657	(1)
Puller for conductor stringing	657	(2)
Tensioner	659	(1)
Reel stands	660	(1)
Conductor stringing	660	(1)
Preparations	660	(1)
Stringing procedure	661	(1)
Sagging the conductors	662	(1)
Terminating the conductors	663	(1)
Clipping-in of conductors	663	(1)
Installation of jumper loops	664	(1)
Installation of dampers and bundle spacers	664	(1)
Conductor replacement	664	(1)
Stringing conductors with optical fibres	665	(1)
Installation of conductors adjacent to or crossing energized lines	665	(1)
Determination of initial sags	666	(1)
Requirements	666	(1)
Position of the conductor on stringing blocks and in clamps	666	(4)
Impact of conductor creep	670	(2)
Example: Sagging data for an overhead line in a mountainous area	672	(1)
References	673	(4)
Commissioning, operation and line management	677	(58)
Symbols	677	(1)
Commissioning	677	(9)
Introduction	677	(1)
Supervision of approval, design and manufacturing stage	678	(1)
Supervision and acceptance of construction	679	(2)
Final inspection and acceptance	681	(1)
Quality assurance	682	(1)
Performance tests	682	(1)
Measurements of tower earthing resistance	682	(1)
Power losses and electrical resistance of conductors	682	(2)
Line energization test	684	(1)
Electrical and magnetic fields (EMF)	685	(1)
Vibration performance measurements	685	(1)
Energization and commence of operation	686	(1)
Operation	686	(7)
Real-time monitoring of conductor ampacity	686	(1)
Targets and benefits	686	(1)
Direct methods	687	(1)
Indirect methods	688	(1)
Examples and experience	688	(1)
Thunderstorm monitoring and forecast	689	(1)
Ice observations	690	(1)
Galloping alerting system	691	(1)
Insulator contamination and performance	691	(2)
Asset management	693	(9)
Definitions	693	(1)
Introduction and targets	694	(1)
Risk management of line assets	694	(1)
Net present value of annual expenditures	695	(1)
Planned expenditures	695	(1)
Risk of failure	696	(1)
Consequences of a failure	696	(1)
Overhead line asset management process	697	(1)
Data base	698	(1)
Management options	699	(1)
Example on management of risk of failure	700	(1)
Basic data	700	(1)
Calculation of planned expenditures and risks	700	(1)
Management options and assessment	701	(1)
Maintenance	702	(25)
Introduction	702	(1)
Inspection	703	(1)
Reasons and procedures for inspections	703	(1)
Inspection classification and frequency	704	(2)
Foundations and stubs	706	(1)
Supports including corrosion protection	707	(1)
Conductors	708	(3)
Joints and fittings	711	(1)
Insulators	712	(1)
Clearances	713	(1)
Corrective maintenance	714	(1)
Strategy	714	(1)
Refurbishment and upgrading of foundations	714	(1)
Renewal of coating, replacement of tower components	714	(1)
Repair of conductors	715	(1)
Replacement of insulators, fittings, dampers and spacers	715	(1)
Tasks and priorities	715	(1)
Dead-line work	716	(1)
Live-line work	716	(1)
Clearing of right-of-way, trimming of trees	717	(2)
Access roads	719	(1)
Earthing	719	(1)
Investigation of line failures	719	(1)
General	719	(1)
Causes of failure	719	(1)
Investigation procedures	720	(1)
Experience on line failures	721	(2)
Reliability and availability	723	(1)
Introduction and definitions	723	(2)
Energy availability, general description and guidelines	725	(1)
Availability	725	(1)
Determination of energy availability, example	726	(1)
Line refurbishment, upgrading and uprating	727	(4)
Definitions	727	(1)
Uprating	728	(1)
Current uprating	728	(1)
Uprating by reconductoring or voltage increase	728	(1)
Replacement of earth wire by optical cables (OPGW)	729	(1)
Upgrading	729	(1)
Introduction	729	(1)
Upgrading of a 380/220 kV river crossing in Germany	729	(1)
Upgrading of a 380/110 kV line in view of increased ice loads	730	(1)
References	731	(4)
Index	735