The edition is a thorough revision and updating of the widely used edition of the same title, commonly known as the "EPRI Green Book" because of . New Green Book Published—Updated Edition Released of EPRI's Landmark Reference Book on Underground Transmission Systems. Hi Senior Power Engineers! I need the Green Book of EPRI. Please share with me or I can interchange many information or software for this.
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Title EPRI Red Book EPRI AC Transmission Line Reference Book: kV and Above EPRI Green Book EPRI Underground Transmission Systems Reference. The Green Book: EPRI Underground Transmission Systems Reference Book ( ). The new. Green Book updates the first edition to reflect the latest . This report is an updated edition of the Underground Transmission Systems Reference Book, commonly known throughout the industry as “the Green Book.
Until his retirement at the end of he was CEO of the Psterer Group in Winterbach Germany , a company he has served for more than 25 years. Contents 2. After the electric-telegraph and the first arc lamp lighting systems, electric techno- logy entered a new historical phase of outstanding acceleration in the last quarter of the 19th century. At the Vienna International Electric Exhibition in , Hyppolyte Fontaine France realized the possibilities offered by long distance transmission of electri- city.
First industrial-scale transmission of electrical power was developed on a long distance transmission between Vizille and Grenoble in by Marcel Deprez for railways. However, until , despite all the efforts of Marcel Deprez, the efficien- cies remained too low for commercial purposes.
The use of transformers gave alter- nating current an essential advantage. Springer International Publishing Switzerland 19 K. This project had a crucial impact on the following history of electricity a good result of this project was that Lord Kelvin, as a chairman of Commission of the Niagara Power station 2 project, sug- gested AC as solution for transmission of power from the Niagara Power Generation Station at the time the largest project in the world HP.
The father of the Transmission project for the Frankfurt Fair was Oskar van Miller from Munich, who later established the excellent Deutsches Museum in there. The line powered incandescent bulbs and an artificial water fall at the Frankfurt fair site. OHL was a 15 kV, later 25 kV, 40 Hz system, on wooden poles with copper conductors 3 12,6 mm2, for a distance of km. The operating voltage was 15 kV, later 25 kV, and the effi- ciency of transmission was The prota- gonists of this historical event can be seen in the nostalgic picture of Figure 2.
The voltage problem was very important in the history of OHLs. Growth and of voltages depends of the history of insulators. The first suspension insulators were invented in enabled, in , the first OHL with voltage over kV. The invention of cap-and-pin insulator in opened the possibility for higher voltage overhead lines. Figure 2. In this spectacular process of the expansion of electric energy in industrial civi- lization, one must stress the decisive role of the International Exhibitions.
In , the International Electric Exhibition had an enormous success and the Scientific Congress organized in parallel brought together the greatest scientists of the time, who adopted the first international system of electrical units. The impacts of the Paris events were the impetus for the constitution of a new professional community, and marked the foundations of the Societ Internationale des Electriciens.
From to , C. Mailloux, President of IEC and Charles Le Maistre, its Secretary General recommended the formation of a specialized body of a technical, scientific and applied technology character. This meeting was considered as the first inaugural meeting of the new international engineering organization.
Cigr aimed to provide an international setting for the discussion and the study of technical questions concerning the generation, transmission and distribution of electric energy. Therefore, when it was founded, Cigr brought together, on one hand, manufac- turers of electrical machines and equipment and operators of power plants and trans- mission lines and on the other hand, electric energy producers, consultant engineers and engineers of major public administration bodies.
In Cigr put in place an ambitious journal Electra, a monthly journal devo- ted to the study of the generation, transmission and transformation of electric energy. The rapid organization and rapid growth of Cigrs Study Committees started in The main subjects dealt within the reports during the inter-war period were:.
Reliability of cables for high voltage, Insulation of lines, the nature and properties of insulators, and dielectric strength of insulation, Earth connection of the neutral and extinction coils, and interference caused in telecommunication circuits.
During the Second World war, Cigr activities stopped naturally just after the pub- lication of the main conclusions of the Session. In , Cigr was the first technical organization in the world which organized an International Conference and brought together worldwide electrical experts to rebuild electrical infrastructure after World War 2, and start with intensive electrification.
In , the fields corresponding to the preferential subjects devoted to over- head lines were divided among no less than 4 Study Committees for the general design dimensioning of lines: SC 22 for towers and foundations blocks, SC for conductors, SC 25 for insulators, SC for very high voltage lines above kV and 3 electrical study committees: Until , groups 22, 23, 24, 25 and 33 alternated with groups 35, 41 and and, as a result, the different fields related with overhead lines were discussed only every four years.
The preferential subjects were then very specific to each of the components: People studied the lifetime of structures in relation to the effects of vibrations, weathering and the associated safety coefficient, conductor creep, Lastly, at the Session, the reduction in the costs of towers was one of the priority subjects. In the late s and early s, Cigrs main priorities for study were the increase in the transmission capacities, mainly by a voltage increase, and the stabi- lity of power systems which were becoming more and more interconnected.
A recur- rent topic was Corona radio interference, which made it necessary to oversize the conductors in relation to the size required for an economic utilization of their ther- mal capacities.
The reorganization of Study Committees in led to a new configuration of the field of overhead lines, with Study Committee 22, officially named Overhead Lines, Study Committee 33 for insulation coordination, and for 36 for interference. This new configuration made it possible to combine within a single Study Committee, all the issues concerning design dimensioning of structures: Thermal and electro- dynamic problems also arose after the increase in levels of transmitted power effects of nominal, exceptional current intensities and of short-circuit currents.
For the first time, in , consideration of the environment in the design of over- head lines, and therefore their acceptability, was chosen as a preferential subject. In the s, the aesthetic of towers design was a major area of the Cigr communitys work. Tubular towers, architectural towers and compact towers were the subject of very interesting presentations and discussions. In the late s, the development of information technology resources became a vital tool in the development of power systems: The development of personal computers led to the development of very efficient software applications, which are now new standards in their respective fields.
In Cigr organize the first Symposium in Stockholm which was Overhead lines impacts on environment and vice versa. From that time began a discussion on how to improve the aesthetic view of OHL in landscapes, impacts of lines on EMC, how to made new standards to mitigate impacts of nature on lines, etc.
Probabilistic approaches were discussed in This was somewhat the starting point of the rapid development in the incorporation of these new telecommunication links in the networks, in spite of the additional constraints they induce on the design and the operation of the lines.
In , since the oldest EHV lines had been in operation for 60 years, the lifetime of structures started to be a concern for operators. It remained one of the recurring subjects of the Sessions, with significant feedback on operation and maintenance methods, considering the strategic stakes attached to these topics.
In , for the first time, live line work aimed to improve the availability of structures, was tackled. In , as a key element in the new approach to communication, the Conference des grands Rseaux lectriques haute tension became the Conseil International des Grands Rseaux Electriques, that it changed from a Conference to a Council.
The area covered by Cigrs field of action was redefined in It now covered not only conventional technical expertise but also economic, environmental aspects and the impact of aspects related to organization and to regulations. In , a new reference model for Study Committees was ratified by the Cigrs governing bodies and gradually applied.
This reference model stressed the need for the proactive cha- racter of the Study Committees, which had to absolutely avoid gradually becoming artificially expanded and self-sustaining techno structures with organization and run- ning costs far exceeding their technical output. In the s, studies and discussions in the area of overhead lines focused on the increase in transmission capacities and on the ageing of structures: The storms observed around year throughout the world led to renewed discussions on the dimensioning of structures based on methods combining static and dynamic loads in a probabilistic approach.
The considerable progression, in terms of general innovation, and of Geographic Information Systems GIS was acknowledge in It was confirmed that they were applied to all phases of the life cycle of a line: To increase the transmission capacities, different solutions were discussed: Lifetime assessment and lifetime extension, precise knowledge on the equipment condition, diagnostic methods, environmental and societal acceptability of over- head lines were other topics in recent group meeting.
In , Study Committee B2 Overhead Lines, counted 22 working groups with experts from 43 countries. References Ishkin, V. On transmission of active power by electricity. Home World 12 Planning and Management Concepts 3 Rob Stephen. Contents 3. Springer International Publishing Switzerland 27 K. In the management of a Transmission line from conception to decommissioning it is important to realise the nature of the line as a device or system and to ensure management structures do not compromise any aspect of the life cycle.
This chapter covers the various management concepts that should be employed as well as the process for line design, construction and maintenance with role clarity provided. The organograms or management structures hierarchy have deliberately been excluded as the concepts may be met in many different ways depending on the uti- lity structure and the insourcing or outsourcing of resources.
A Transmission line, as defined in Chapter 14, is a device that transmits power over long distances. It should be seen as a single device or system with electrical properties that contribute to power transmission within the supply grid. Chapter 14 outlined how a line can be tailor made to meet the system planners requirements within the grid.
A line can also be regarded as a large mechanical structure system spanning many kilometres over many terrain types that must endure varying adverse weather conditions.
It is therefore a device requiring mechanical, civil, environmental, geo- technical and electrical consideratons in the design of the line. This section deals with the different possible management concepts for the line from planning to commissioning.
This is either outsourced or performed in house by a separate division. The tower design is determined from the phase configuration and bundle configuration supplied and is considered fixed. Likewise the foundation design is then determined based on the loadings provided by the tower designers and is also considered fixed. In this model the tower designers do not consider or question the reasoning behind the conductor bundle and phase configuration but convert the requirements into loads for a tower to withstand.
Likewise the electrical engineers who determine the conductor bundle and phase spacing maybe ignorant as to the effect their requi- rements have on the mechanical aspects of the line. The series model and distance between the disciplines is often further exacerba- ted with outsourcing of tower and foundation designs.
This often requires a specific scope and specification which has little flexibility. The series model will result in sub optimal designs in most cases.
It is a more simple model to manage than the iterative model described in the next section. This is because each aspect affects the other. For example an electrical engineer may specify a 6 bundle Zebra conductor with a certain phase spacing for a kV line. The tower designer will design accordingly without comment in the series model. However, if the iterative model is applied, it may be found that a quad bundle with a lower steel content conductor with slightly wider phase spacing could be used at a reduced cost due to the lower mechanical forces wind load and guy wire for example.
If the line is to be optimised as proposed in Chapter 14, then the design of the line cannot be performed in series with the planner determining the conductor type and the tower being designed based on the conductor specified followed by foundation design. The iterative model is more difficult to implement from a management viewpoint as it involves engineers from different disciplines working together and understan- ding each others field with regard to transmission lines.
This can be achieved in a number of ways:. In house design insource: The aim is to create a group of line design engineers with in depth knowledge in one of the disciplines. Tower detailing and detailed foundation design can still be outsourced after the tower outline is opti- mised and conductor bundle and type chosen.
In house management outsource: The contracting of the engineers may be done on a time basis and not on an output based using a defined scope.
The route selection and acquisition may form a separate project as the time duration is normally far longer than the construction period. However, a project management approach with designer involvement is recommended. This team may include a variety of environmental, legal, negotiators and technical experts some of which may be outsourced.
It is important that the negotiator understands the line design as well as the impli- cations of certain concessions made with the land owner. An additional strain tower to avoid a certain point in the land or to follow the border of the property can increase the line cost overall. It is important that the line designers are part of the team to advise on technical matters as well as to be aware of the agreements reached.
In addition to all the permits required for a line to be built, it is also important that the team include wildlife experts for flora and fauna as well as bird experts to ensure flight paths and nesting grounds are catered for. The project team for the route selection and property acquisition is often the largest and most diverse of teams required to realise a final constructed line. It is also the longest serving. For this reason the handover to different Project Managers needs to be well managed with decisions clearly documented.
The construction phase consists of construction activities and handover for operation. This phase is best managed by a team under a project manager using matrix management whereby the team members are seconded to the team from manage- ment. The Project Manager decides on the timelines and outputs and informs the team members. There may be a sub structure in the team for environmental, design, construction elements.
The team can be outsourced or insourced to varying degrees depending on the company. If the team is totally outsourced from various suppliers it is important not to duplicate the structure with in house staff. This could result in an in house project manager managing the outsourced project manager with duplication of work, con- flicting instructions to contractors etc. If the project manager is outsourced the in house resources need to manage the outputs and milestones by exception and not interfere with the team below the Project Manager.
It is also important that the project manager be appointed as early in the project life cycle as possible so that he understands the reasons for the design chosen, issues with line route and stakeholders. It is also desirable that one project manager be accountable from the start to the end of the project to avoid handover points with possible misinformation arising. It is also necessary to have one person accountable for time, cost and quality to avoid blaming later in the project. In any management structure it is important that roles and accountabilities are cle- arly defined.
The three main role players in the establishment of a line are the Network Planner, Project Engineer and Project Manager. These may work for diffe- rent companies and be contracted separately. They do need to fulfil the responsibi- lities as listed below.
The following roles are responsible for the design and construction of overhead lines-. Responsible to ensure the project is released for preliminary design timely. To ensure correct targeted in service dates are communicated. Project Engineer To assist in the route selection process To ensure the consultative process is followed relating to the design options and selection of the optimum design.
To ensure full understanding of all aspects of the line design as well as how to implement this on site. To assist the Project Manager in the construction phase of the project.
Project Manager To ensure milestones are set and resources are arranged so that target dates are met. The project manager is to understand the nature of lines and the types of pro- blems and issues that may result from the line design and construction process.
To take charge of the programme target dates, milestones , from the pre- engineering stage to final commissioning. The project manager is to authorise all costs to the line.
This is to include over-heads which are normally accrued without the project manager being aware of them. The life cycle of a transmission line commences with the system planner and is completed when the line is decommissioned. This section deals with the planning, design and construction aspects. As mentioned in Chapter 14 the planner is to provide information on the electrical requirements of the line. This can be submitted in the form of a table as indicated below.
Note that even if standard designs are used, it is useful to have the require- ment specification from the planner to check whether the proposed standard design will meet the requirements. The planner should provide the information to the line designers as indicated in Table 3.
A few fields may need explanation. The profile of the proposed line load on a yearly and daily basis is essential for the designer to determine the templating temperature of the line.
If the load pro- file shows a morning peak and a winter peak it may be possible to use a smaller conductor as the temperature reached under peak load may be relatively low.
If the daily load profile is very peaky, it may be possible to use small conductors with a higher templating temperature. If the load profile is flat it may be neces- sary to use larger conductors with a lower templating temperature. Table 3. Project Project name and number of line to be built.
Name Start Sub Substation at which the line starts. Name and reference of Network development plan Planner enter name of planner responsible Year 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Load MVA Hour 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Profile Month 1 2 3 4 5 6 7 8 9 10 11 12 Profile Imped.
The load growth is necessary to determine the optimum aluminium area of conductors. The impedance is necessary to determine the optimum bundle and phase confi- guration AC lines.
The designer needs two values, a minimum and maximum value to ensure the optimum impedance to the network. The voltage of the line is often fixed and cannot be altered, however, in certain cases the costs can be such that the lower voltage option provides a major cost saving.
For example a 10MVA load required to be transferred at kV may prove far more effective at 66 kV sub transmission The time the line is required is often exaggerated by the planner who expects a certain load growth, however, there are times when the utility can lose substan- tial amounts of revenue should the line be delayed.
In these cases it is often cost effective to utilise more than one contractor and fast track the project. In addition to the above the maximum voltage level and fault level needs to be spe- cified. The reliability level also needs to be specified by the system planner. Line ratings normal, emergency also need to be known these may be a minimum and the line designer must ensure these are met. The selection of a line route is often a very time consuming task that could take many years in some cases over In the management of the line route acquisition it is important that the route of least objection is not always obtained.
It is often required that the route chosen is along the border between properties or along a road. In this case there is normally a large amount of bends and angle structures required which results in an increase of the overall line cost.
Management needs to be cognisant of these issues when appointing consultants to obtain route or when using in house resources.
In contracts for negotiators, if they are outsourced and in house resources are not utilised, the payment method should include the cost of the line as a result of the route chosen. This could include for example a ratio of tangent suspension to angle or strain towers.
A project management approach is also recommended for this process as it covers many years, different resources and involves many public forums which require knowledgeable presenters. The project team may include environmentalists, negotiators, surveyors, marketers, design engineers and even health professionals if the electromagnetic field issues are raised.
As the process is a long one, the decisions and concessions taken need to be clearly documented and stored in an organised manner to ensure that no concession is overlooked in the design and construction phase. Concessions may be made to land owners in the early stages of the route acquisition.
Chapter 6 and Cigr TB cover the requirements for property route selection, consultation models and property acquisition. As proposed in Chapter 14, the purpose of this stage is to determine a group of design options ten options provide a wide range that will ensure possible optimisa- tion and, via the use of optimisation tools, to select the final group options for further analysis.
The number in the final group may be around 3 or 4 depending on whether an option is obviously superior. The project engineering team is to be formed under a knowledgeable line design expert. The team should include members knowledgeable in conductor, tower and foundation issues. This encompasses electrical, mechanical and civil disciplines.
As mentioned in section 3. Possible routes can be determined from the digital terrain map or from the Environmental Impact Analysis. If this is not possible the design team should select a profile similar in nature to that expected in the line that they are designing.
The line route can seriously affect the overall cost of the line. It is imperative that the line design leader approves the line design route prior to final negotiations and servitude acquisition.
The possible conductor and bundle options are then considered. The tower family can then be determined from the selected terrain either the actual terrain or a sample selected from terrain that is similar in nature using the conductor families selected and the available tower families. The planners are then to be consulted again to ensure that the proposed set of line design options is in line with the planners requirements. The best approximately four options are to be taken to the next stage.
This can be achieved by using the programme spreadsheet that determines the scores for each option. The motivation for project finance may be made in the preliminary design phase is to be completed.
This is to include the following: A design document which should contain the following information: Reason for the line including extract from the planning proposal documenta- tion. This normally includes the Net present value cost benefit analysis.
Information from planners on line requirements including time and cost constraints. Possible routes with cost options if possible. This may vary from country to country.
Options selected for analysis. Design options to be analysed further. A cost estimate of the following Labour cost to complete the detailed design stage. Cost of the geo tech survey Cost of tower development if required.
The cost estimate is to be added to the project costs for approval via the relevant governance procedures. Note that the geo tech survey is often overlooked. It is a critical aspect of the detailed design stage.
It determines the suite of foundation options that should be used on the line. It assists in determining the numbers to specify in the enquiry document or for construction.
It also highlights the type of foundations that need to be designed or developed. The detailed design phase precedes the execution phase. The output of this phase is a detailed design and costing which is then presented to management for execution approval. In some cases the utility may decide to go to market to obtain actual tendered prices for submission to management. In other cases estimates may be made from previous projects.
In the former case the risk of error in costing is lower.
Approval is normally required from management for the detailed design phase to commence. This can only be achieved if the following are known:. The line route and line profile.
The tower positions and types per position. The detailed bill of materials including conductor, towers, insulators and fittings. The contract prices for the erection phase as well as material costs. It should be noted that the construction and material costs can be very volatile and depends on the exchange rate, the availability of materials and labour.
It can vary from line to line even if they are in the same geographical area. The line route and actual line profile as accurate as possible needs to be used to determine the optimum tower, conductor and foundation combination. The options short listed from the ATI analysis are to be used to determine the opti- mum combination.
These are to be used using the actual line profile and line route chosen. Tower spotting packages should be used to determine the best option in rela- tion to the ATI. This will mean that network planners have to be consulted once again to determine the best option including the R, X, B values as well as the cost of losses.
Note that the best design combination is to be determined together with Maintenance staff. Preferably there should be a technical governance structure which will assess the proposed design option. This committee should consist of maintenance and operation staff as well as line designers and system planners. These may be from different companies.
If new towers are to be designed, it is necessary that the maintenance and construction staff are to be involved. This could mean engaging with contractors who are likely to be involved in the construction of the line.
Once the best combination is determined, it is necessary to optimise the tower selec- tion for each tower position using a tower spotting programme. This is best perfor- med by a peg walk of the route. A peg walk or tower staking is a walk down the line by the line designers to determine if the proposed tower selection in the proposed tower sites are optimal. This also includes accessibility, constructability and proximity to roads, drains or even unmarked graves that may not have been known about when the line was profiled.
In order to determine the type of foundation to use at each site, it is necessary to perform a detailed geotechnical survey at each tower site. This can only be perfor- med after the tower, foundation and conductor combination has been chosen and the first selection of tower types per site is completed. The peg walk can be conducted at the same time as the geo tech survey.
The peg walk will determine if any tower position changes are required or if a different tower needs to be placed at a specific location.
In addition access roads can be planned as well as farm gate positions and types of gate e. The information gained from the peg walk and geo tech survey can be used in the finalisation of the Environmental Management programme which is essential for each project. The information available at this point is the full tower schedule, the detailed bill of materials, the line profile with tower types, the access road locations and gate locations and types.
This information may then be compiled into an enquiry document. The docu- ment is then sent to prospective contractors for tender. Once the tenders are received it is necessary to analyse the tender in detail. The services of a quantity surveyor should be used at this stage.
Once the appropriate tender has been selected the price and motivation needs to be submitted for approval this will depend on the utility governance requirements , it may be permitted to proceed if the tendered prices are within a certain percentage of the estimate. Planning information Reason for the line including extract from the planning proposal documentation. Survey and Environmental Possible routes with cost options if possible. Route and profile Initial tower, conductor, foundation combinations Options selected for analysis.
ATI analysis and results. Design options to be analysed further Towers Tower design chosen with reasons Tower schedule summary Conductor and earthwire Final conductor or conductor bundle chosen with reasons. Final earthwire chosen with reasons. Note the earthwire selection is dependent on the fault level as well as the fault dissipation in the towers and ground.
This analysis is to be performed as part of the earthwire selection. In addition the interference criteria for telecommunication lines are to be taken into account and described here. Contracts tenders received Summary of tenders received with technical analysis as to their suitability. Once the overall project is approved by management, the contractor responsible for construction may be appointed.
An overhead power line is unlike a substation in that there are many factors that cannot be taken into account before construction begins. Items such as access to site, soil types and tower erection methods may necessitate that the tower type, foundation type, equipment used or tower location be changed on site subsequent to the design being approved.
This includes right of way clearing requirements and stringing specifications location of equipment, drums. The following items should be discussed:.
Note that the control of material on site is critical to the success of the pro- ject. Nuts and bolts as well as spacer dampers, and insulators should be kept in a clean environment preferably off the ground. Composite insulators should be handled in accordance with the Cigr composite insulator hand- ling guide Cigr TB TB There must also be a system whe- reby the material issue is controlled and the stock levels are known.
A person should be placed in charge of the store which should be fenced off. Note that line and road crossings need detailed up front planning. In the case of line crossings the permission to take the line out needs to be obtained from the Operations authority. The detailed bill of material, tools, and pro- cedure needs to be drawn up and agreed to well in advance. Special items such as cranes, helicopters etc may also be required. This activity occurs after the permission has been obtained from the relevant authorities rela- ting to the crossing.
The EMP is a plan to meet the environmental requirements of the line. It includes the rehabilitation of the environment. Note that this will include the formation of access roads, the clearing of the servitude and whether tyre or track vehicles are to be used. Note that it may be possible that certain foundation designs will need to be done or modified.
There may, for example be a large rock area and rock piles may not have been designed. Or the contractor may not have the drill bits for the type of rock foundation required. This needs to be taken into account and resolved up front. Note that this is a standard item on all site meetings.
It includes the safety procedures and equipment required and available to staff. This is due to the fact that the contractor is likely to err on the conserva- tive side or on the side of higher financial returns. The foundation types need to be documented per tower installation. An example could be a drain or grave that is found to be in the foundation location.
In these cases where a tower needs to be moved or a plan made on other matters, it is essential that com- petent backup available for assistance. The Project Engineer is to ensure that this back up is available.
These changes must be controlled in the fol- lowing manner:. The Project Engineer is to examine the proposal and agree to the change if applicable. The Project Engineer is to ensure the design document as well as line profiles or other drawings as appropriate are updated once approved and executed. The cost of the change is to be determined by the Project Engineer. The reason for the change as well as the cost is to be submitted to the project manager for approval.
The Project Manager needs to sign off the proposal and update the project costs and, where applicable, the projections both cost and time. Note that in order for the Project Engineer to understand the issues relating to problems on site he is to visit site regularly and have a very good under- standing of the requirements of the project and the final design option chosen.
The COW are the eyes and ears of the customer on site. They need to have knowledge of what is required to be done on site to ensure that the contractor is executing the work correctly. Assembly and erection of structures. Stringing of conductors including running out, regulating and clipping in. In some cases it may be necessary to have more than one COW on site at one time and certain COWs may be specialised different areas such as foundations, tower erection and stringing.
Examples of these include:. Cube and slump tests for concrete Pull out tests for guy anchours. Tests may also be required in the laboratory such as tensile tests for compression fittings and Guy anchor assembly tensile tests.
Tower footing resistances need to be measured per tower and documented. Impedance measurements should be conducted on the completed line to compare them with the designed values as well as to update the planning and fault level parame- ters with exact values thereby enabling a more robust planning database to be created.
A list of defects need to be created which needs to resolved within a specified time. However, they must inform the Project Manager who needs to make arrangements. The design staff must not communicate directly with the Contractor unless the Project Engineer or a representative of the Project Manager is present.
The following staff that are involved in the following activities need to be accredited to perform these functions:. Design document It is assumed that the design team would have sufficient knowledge to conduct the design process.
The Design document needs to have each section signed by the designer and a person who is checking the section. The latter needs to be a registered professional Professional or certificated engineer depending on the country. Tender evaluation The technical evaluation of tenders needs to be performed with the presence of at least one expert in the field of line design. This needs to be a Professional engineer or registered professional. Foundation nomination A technician approved by the foundation designer or member of the design team assigned to foundations must be a registered profes- sional should carry out nominations.
Clerk of Works the clerk of works needs to have had training and experience in each of the fields mentioned before he may oversee the work in these areas.
Records of site visits by the design engineer as well as the findings must be recorded on site together with the required actions. Planning proposal concept release of project and pre-engineering funding is obtained to conduct the concept design. The output is the conductor, tower and possible foundation combinations. Obtaining of servitude and Environmental approval. In some cases this may take up to 20 years. In cases where it is likely to take longer than years a separate project may be commenced.
Often, however, the negotiations may require a final tower design to be presented. In this case the concept design will need to be conducted. Perform pre-engineering design and determine a short list of options that could be investigated further. Submit the project for detailed design stage approval and funds for detailed design.
Obtain route and line profile. Determine the optimum conductor, tower, foundation combination. Determine tower positions and types per position. Conduct geotechnical survey, peg walk to determine gate positions, foundation types and access road. Complete Environmental Management Plan. Complete and issue enquiry documents based on results of optimisation and geotech survey. Evaluate tenders using line design experts and quantity surveyor Compile and submit request for permission to construct line to Investment committee or management structure Conduct pre-construction meeting Construct line.
Process for inspection and commissioning. Note that in some cases the steps 10 and 11 take place after the step This is due to the time required for step This is not ideal, however, as the cost of construction submitted by contractors is difficult to determine upfront and depends on workload, competition and cash requirements of contractors. It is critical, that the step 5 is obtained before steps The temptation is to begin construction or issue the tender before the route or line profile has been completed.
As the line is useless until completed, by commencing the line too early may result in a weaker case for obtaining the route right of way or servitude or standing time claims from contractors. In cases of extremely long lines it may be prudent to commence construction on a sec- tion if the line route on the remaining sections can be altered if need be. It is a fallacy that the quicker the tender is issued the quicker the line is completed.
It is preferable to have all permissions approved prior to com- mencement of construction. It is critical that the maintenance staff are involved in the design of the line irrespec- tive of whether the towers and conductors are standard or not. This is to ensure access to towers is mutually agreed prior to construction as well as maintenance methods.
In the case of Live line maintenance the maintenance staff must be involved in determining the live line maintenance methods prior to design finalisation. Special tools may need to be developed or insulated cranes or personnel lifts downloadd. In cases of new tower designs it is necessary to determine the adequate spacing by using dummy objects with full scale electrical impulse tests. This will determine whether the spacing proposed is adequate.
It is critical that the asset owner and maintenance staff be involved as early as pos- sible in the construction of the line. A detailed handover check sheet needs to be established and agreed to prior to the commencement of construction.
This should include checks per tower. Maintenance of the constructed asset may be contracted out to a number of exter- nal suppliers.
It is important for the asset owner to ensure that, prior to taken over the line, all information is available on the line that has been constructed or refur- bished. This includes:. Line as built profiles Map of line route with landowner details Tower type per tower position Conductor details supplier, type, contract, numbers etc Earthwire and OPGW details supplier, type, contract numbers etc Hardware details supplier, type, contract numbers etc Drawings of towers and assemblies.
Foundation types per tower leg this is particularly important with large tower footing areas such as the cross rope suspension Results of concrete slump and test cube compression tests. Tower footing resistance per tower. Earthing used especially if additional earthing has been applied. Accessories such as aerial warning spheres, bird guards. Insulator types per tower if different composite and glass may be used on one line for example , information to include creepage, material, insulator profile.
Location of conductor joints as well as the compression tool number to perform the joint if such joints were installed. In addition to the above it is important that the maintenance required is also provi- ded.
This includes the type of inspections to be conducted and the time interval. Items such as retensioning guy wires should also be included. Regular line inspections should be conducted with focus on the following:. Tension in guy wires Evaluation of the earthing system at the towers Structure condition Vibration and spacer damper condition and orientation Aircraft warning spheres, condition Condition of guy anchors Insulator damage Servitude condition and access to towers poor maintenance of servitudes could inhibit effective restoration of lines as well as affect line performance depending on the vegetation below the line.
Thermal imaging of the line for potential electrical hot spots Periodic assessment of the conductor especially in corrosive environments this may entail taking physical conductor samples and testing them in a laboratory Records should be maintained with the fault information for each line so that analysis and performance improvement projects can be undertaken if necessary.
The current utility structure often differs from vertically integrated to fully outsour- ced with many different companies involved in the life of the asset. This chapter highlights the concepts for management of the line in the different stages.
The organogram or management structure can vary between utilities and companies and still comply with the proposed concepts. As a result the management structures have not been discussed. The aim is to make the utility aware of the management concepts to be applied and to apply these in the best manner that befits the company structure and insour- cing or outsourcing policy.
The management of the line life cycle is consistent irrespective of the structure of the company or companies involved with different stages of the life cycle.
It is important for the asset owner and operator to be aware of the management concepts and process to ensure all stages are well catered for even if they fall outside the domain of the company.
The concepts highlighted in this chapter have been proven over many years and, although they may vary from country to country in detail for example it may not be practice for the planners to provide the information as suggested and only state a conductor type , each stage must be covered to some extent.
It is likely that the planning, design, construction, maintenance and operation of overhead power lines will be conducted by different companies with different goals, make up and skills compared to the past. In this case it is important that the process through the life cycle of the line is not compromised. This can be achieved by the role players being aware of the process as described in this chapter.
The risk exists that the more independent the role players are the less the overall planning and management concepts will be understood and executed. This risk is likely to increase in future as the role players become more segregated.
References Cigr TB SC 22 WG High voltage overhead lines. Environmental concerns, procedu- res, impacts and mitigations Cigr TB Composite insulator handling guide Cigr TB He has been involved in all aspects of line design as well as network planning, electrification and project management. In study com- mittee B2 overhead lines he has held position of working group convener, special reporter, advisory group convener and was chairman of SC B2 from He has published over papers and been involved in technical brochures on aspects of thermal rating, real time monitoring and overall line design since He is an horonary member of Cigr and a fellow of the South African Institute of Electrical engineers.
Contents Section 1: Corona Losses, Insulator andHardware Losses Jardini E. Ribeiro Florianpolis, Brazil e-mail: Springer International Publishing Switzerland 47 K. Nolasco et al. DC Transmission Lines 4. Electrical parameters of transmission lines or otherwise refered to as line cons- tants, resistance, inductance and capacitance R,L,C are used to evaluate the electrical behavior of the power system.
Depending on the phenomena to be studied a different set of parameters is required. For load flow and electrome- chanical transients the parameters used are the positive sequence. For the former case, normally, the line is considered full transposed and there are simple equations to determine the parameters. For others cases digital programs are used like the ATP. The various procedures of calculation are discussed here-in-after, starting with straight forward calculation for positive sequence model and comple- ting with a general calculation.
The resistance of conductors R is found in the manufacturers catalog. R -the resistance of the bundle- is then the one sub-conductor resistance divided by the number of them in a bundle. It should be noted that manufacturers catalog indicate, normally, conductor resistance R20 for dc at 20C.
For other temperature Rt a correction shall be applied:. Aluminum Association provides specific values of for every conductor section in the ranges C and C. Table 4. For a single circuit fully transposed:. For bundle of n sub-conductors located in a circle of radius R and being a the equal spacing between adjacent sub-conductors the equivalent radius of the bundle or the GMR is:.
Negative sequence parameters are equal to the positive parameters for transmission lines. There are straight forward equations also for the calculation of the zero sequence parameters, however it is recommended to use the procedures described in Stevenson ; Happoldt and Oeding ; Kiessling etal.
In this section formulae will be presented for calculating voltage, current and power at any point of a transmission line, provided such values are known at one point. Loads are usually specified by their voltage, power and power factor, for which current can be calculated for use in the equations.
Normally transmission lines are operated with balanced three-phase loads. Even if they are not spaced equilaterally and may not be transposed, the resulting dissym- metry is slight, and the phases are considered to be balanced. The equivalent circuit of a short line is represented by a series reactance only, which are concentrated or lumped parameters not uniformly distributed along the line.
As the shunt admittance is neglected for short lines, it makes no difference, as far as measurements at the ends of the line are concerned, whether the parameters are lumped or uniformly distributed.
The shunt admittance, generally pure capacitance, is included in the calculations for a line of medium length. The nominal circuit, shown in Figure4. In this circuit, the total shunt admittance is divided into two equal parts placed at the sending and receiving ends of the line.
The voltage and current relationships used in electrical calculations under this approach are:. Published in the first edition with a green cover, the book has become commonly known throughout the industry as "the Green Book. The Green Book provides a desk and field compendium on the general principles involved in the planning, design, manufacture, installation design, installation, testing, operation, and maintenance of underground cable systems.
It is one of a series of landmark EPRI transmission reference books—on overhead line transmission, underground transmission, wind-induced conductor motion, and compact line design—first published in the s and s and currently being updated.
However, in recent years, despite the value and popularity of the Green Book, some elements of its content have become increasingly outdated, and do not reflect the latest developments in technology and utility practices. For example, there has been an increased use of solid dielectric cable at higher voltages, which was not mirrored in the edition.
In addition, there is a need today for the book to incorporate more of an international perspective on underground transmission design and use. To capture the current state-of-the-art in the field of underground cables, EPRI initiated a research project in to update and expand the book. A team of international experts was assembled to review the existing edition of the Green Book, propose a revision plan, and revise the book as needed.
The project resulted in the publication in March of a new and expanded edition of the Green Book. The new edition of the Green Book product no. The content of the earlier edition has been significantly expanded and updated. The new edition provides information to better reflect the latest technology, new materials and methods, recently issued standards and regulations, and current utility needs and practices.