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• Power Line Product Design Guide

Power Line Product Design Guide

This guide provides you with operation suggestions of power line design in Greenwich. The related references of design is also offered. Read this section to get acquainted with the design procedures and regulations.

The Greenwich power line product V2.0 has the capability to output designs in various phases based on the Greenwich platform and ecological side. It is applied to improve the design efficiency and optimization in scenarios as turbine bidding, scheme design in various phases, concurrent design, etc., which greatly minimizes the cost and maximizes the efficiency of power line project. Currently, the design and operation of aerial, cable, and mixed schemes are supported.

Design References

This guide is formulated based on the following standards and regulations:

• Code for design of 66kV (and below) aerial power line (GB 50061-2010)
• Technical regulation for design of aerial power line tower structure (DL/T 5154-2012)
• Technical regulation for design of aerial power line foundation (DL/T5219-2014)
• Code for design of voltage protection and insulation coordination of alternating current electric device (GB/T50064-2014)
• Regulation for design of power line protection against telecommunication line’s danger and disturbance impact (DL/T 5033-2006)
• Code for design of alternative current electric device ground connection (GB 50065-2011)
• Code for design of steel structure (GB50017-2013)
• Code for anti-seismic design of electric device (GB 50260-2013)
• Code for design of electric engineering cables (GB 50217-2008)
• Design manual of high-voltage power transmission line in electric engineering (second edition)

Operation Procedure and Related Suggestions

This section introduces the main operations in power line design and related parameter setup guidelines.

Basic Operation

For main operation steps in Greenwich power line product V2.0, refer to the user guide in Greenwich documents.

Route Optimization

• If the project is during Phase II, refer to the existing material for accurate design parameter inputs.

• The Greenwich power line product V2.0 consists of three calculation types: wire optimization, tower arrangement, and electric check. Among them, the wire optimization algorithm consists of aerial route algorithm, cable route algorithm, and mixed route algorithm.

  
  • Under common conditions, it is recommended to select mixed route algorithm.
  • Select cable route algorithm when you encounter the following conditions:
    • The project is in the typhoon area. (Wind speed > 30 m/s. Check the wind zone map in China for details.)
    • The project is in the frequent thunderstorm area (Thunderstorm day ≥ 90 days. Check http://www.cxspd.com/lbr-cx.html for details.)
    • The project is in the heavy icing area (Icing thickness ≥ 15 mm. Check the ice zone map in China for details.)
    • The aerial scheme is not applicable due to policy reason or other reasons of project.
    • The aerial scheme is not applicable technically for the project, such as span.
  • If you want to compare the economic result of the three algorithms, perform the calculation of each of them.

• While importing external map or route scheme, ensure all input files are in the same coordinate system or can be converted to the same one. Ensure the imported route scheme, turbine layout scheme, map file, avoid area file, etc. are in the corresponding coordinate system or can be converted to the same one.

  

• Avoiding range is consisted of buildings, basic farmland, mineral area, forest area, natural protection zone, etc. For each of the three schemes, aerial, cable, mixed route schemes, define these avoiding ranges to avoid to design within them.

  If the project-related avoiding ranges are too many (over 20), it is recommended to perform wire optimization calculation, draw the areas over the avoiding ranges, and perform the wire optimization calculation again over the power line scheme.

• Four terrain options are available for wire optimization: hilly area, flat ground, heavy icing flat ground, and heavy icing hilly area. Judge your selection according to the contour map and icing thickness of the project.

  • When the icing thickness is less than 15 mm, altitude is more than 500m, and relative height difference is no less than 200 m, select hilly area.
  • When the icing thickness is no less than 15 mm, altitude is more than 500m, and relative height difference is no less than 200 m, select heavy icing hilly area.
  • When the icing thickness is less than 15 mm, altitude is less than 500m, and relative height difference is less than 200 m, select flat ground.
  • When the icing thickness is no less than 15 mm, altitude is less than 500 , and relative height difference is less than 200 m, select heavy icing flat ground.

  The relative height difference is the height difference between the highest and lowest points in the wind farm.

• Seven terrain options are available for wire optimization: sand, water, farm, wild, bush wild, low bush, and forest. Judge your selection according to the reconnaissance and information collection conditions from the project.

• After the route optimization calculation is completed, check the applicability of the circuit scheme according to the following rules:

  • The selection of aerial circuit scheme should follow the requirements below:
    • Avoid crossing with other facilities. If the aerial wire crosses other wires, do not locate the cross point at the tower top of the spanned wire.
    • Avoid to locate aerial circuit within depression, scoured zone, ill geologic area, virgin forest, and other areas influencing secure operation of wires.
    • Do not erect aerial circuits across forest. If it is inevitable, avoid deforestation by selecting wire paths based on the roads and other specific conditions in the forest. For 35 kV and 66 kV aerial wires, design them in the span form. In special areas, restrict deforestation with consideration of electric safe distance at the specific district.
    • Aerial wires should not go through the core zone and buffer zone of the natural protection zone authorized by the country.
  • The selection of cable wire scheme should follow the requirements below:
    • In principle, lay the wires along the wind farm road. The start point is turbine or turbine transformer, and the end point is substation.
    • Avoid mineral area, basic farmland, and districts influenced by severe erosion of acid, alkali, and random current electrochemistry.
    • Without safeguard measures, avoid areas harmed by white ant, heat source, and districts vulnerable to external damage.

Tower arrangement

• During the tower arrangement operation, nine types are available in the Typical Meteorological Area drop-down menu. Select one according to the actual maximum wind speed (average maximum wind speed in 10 minutes collected at the height of 10 m of an open flat ground in 30 years), icing thickness, and minimum temperature. Refer to the values circled by red squares in the following figure.

  

  Check the details in state grid wind zone map, state grid icing zone map, and minimum temperature table of provinces corresponding to the location of the wind farm project.

  Note

  Adopt the maximum values in icing zone map and wind zone map.

• During the tower arrangement operation, the default value for Typical Span is 250 m and for k value is 0.32. Define the value of Safety Distance according to the actual situation of the project.

  

  • For scenarios with radical and competitive engineering quantity, such as bidding, set the Safety Distance as 7.
  • For scenarios with relatively conservative engineering quantity, such as feasibility study, set the Safety Distance as 11.

  The higher the safety distance, the higher the tower. The weight of tower thus increases, so does its cost.

• The location of tower should be selected with consideration of the stability of tower and foundation and convenience of construction, operation, and maintenance. Do no erect tower at the following location:

  • Location with possibility of landslide and mountain torrents
  • Location with possibility of car crash
  • Unstable area that might shift to watercourse
  • Partially unfavorable geological location
  • Safety-threatening location with holes of underground pipeline

Electric Validation

• After the electric check is completed, click the tower in the Question Object column to adjust the scheme according to the tips.

  

• It is suggested to learn some knowledge of tower model. For the algorithms introduced in Greenwich, the 35 kV tower of state grid is recommended. Its model is 35B01-Z1-15. Within the model name, 35 stands for voltage grade, B01 stands for tower module, Z1 stands for linear tower, and 15 stands for tower height.

PBOM Estimation

• For objects which are re-calculated for wire scheme and tower arrangement, click the Generate button to overwrite all manually modified PBOM parameters with newly generated PBOM. For objects that have not been re-calculated, do not click the Generate button.

• The PBOM can be downloaded as an Excel file with many rows. Check the data with the PivotTable function. For details, follow the steps below:

  1. Click PivotTable to insert it in the current sheet.
  2. Click the PivotTable, and select the Material, Unit, and Quantity and Price columns.
  3. Drag the Material field to the Row area and Quantity to the Value area.
  4. Click Enter.

  After the operation in PivotTable is completed, a table listing the engineering quantities is generated as shown in the figure below:

  

• Select cable model according to the following rules:

  • If the cables are within the cable circuit in wind farm, select aluminum cable and use the aluminum cable database.
  • If the cables are those from terminal station to substation, select copper cable and use the copper cable database.
  • If the cables are those from turbine transformer to tower, select either aluminum or copper cable.

CAD Drawing Generation

• The drawings generated by power line design are in the CAD format. You can modify them if necessary. It is suggested to install CAD software package before opening the drawings.
  • When the project is designed with cable scheme, two drawings are generated automatically: wind farm integrated power line wiring drawing (connecting) and circuit route drawing (RouteDwg).
  • When the project is designed with aerial scheme, five drawings are generated: wind farm integrated power line wiring drawing (connecting) and circuit route drawing (RouteDwg), foundation overview drawing (Foundation), tower overview drawing (TowerGeneral), and tower detail sheet (VolumeTower). Among them, the tower detail sheet is not mandatory in the feasibility study phase. You can choose to generate it or not according to the actual situation.