Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
MODULAR LATTICE TOWER TO BUILD A HIGH VOLTAGE AERIAL ELECTRIC TRANSMISSION LINE, WITH VARIABLE MULTI-PURPOSE ARRANGEMENT, ITS MODULAR SYSTEM AND METHOD OF CONSTRUCTION
Document Type and Number:
WIPO Patent Application WO/2022/123521
Kind Code:
A1
Abstract:
Lattice tower for overhead power lines in High Voltage including a base anchored to the ground and a body ending with a top portion (4) designed to anchor respective conductors (5) of an HV power line; wherein the top portion (4) consists of a modular system (6) to realize a reticular structure of parallelepiped shape formed by at least four straight uprights and a plurality of angles arranged transversely to the uprights to connect the uprights to each other by fixing them in a vertical direction (V) and parallel to each other, so that the top portion (4) has a recursive configuration forming a plurality of three- dimensional modules (8) identical to each other arranged sequentially in the vertical direction (V) to obtain a 66kV lattice tower and, with the addition of an additional independent three-dimensional module, a 135/150kV lattice tower.

Inventors:
SPEZIE ROBERTO (IT)
MATLI PIERO (IT)
CARBONE MAURIZIO (IT)
DI VITO ENRICO (IT)
BERARDI PIERO (IT)
Application Number:
PCT/IB2021/061573
Publication Date:
June 16, 2022
Filing Date:
December 10, 2021
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
TERNA S P A (IT)
International Classes:
E04H12/10; E04H12/24
Foreign References:
CN106368495A2017-02-01
DE202015003670U12015-11-05
EP2921613A12015-09-23
CN110566029A2019-12-13
EP3190245A12017-07-12
CN107905614A2018-04-13
Attorney, Agent or Firm:
PLEBANI, Rinaldo et al. (IT)
Download PDF:
Claims:
C L A I M S

1. Modular system to realize a lattice tower (1) , especially for a high-voltage overhead transmission line, said lattice tower (1) comprising a lattice structure including a base (2) , which can be anchored to the ground, a body (3) and a top portion (4) configured to connect respective conductors (5) of said high-voltage overhead transmission line; characterized by the fact that it comprises :

- at least four straight uprights (36) having a first prefixed length, the straight uprights being configured to be connected to each other with a plurality of angles (20, 21, 37) arranged transversely to the uprights and to be fixed in a vertical direction (V) and parallel to each other on the body (3) , so as to form a first straight reticular structure (38) of parallelepiped shape;

- a first set of transversal crossarms (10, 11) made of lattice structure and which can be fixed laterally on opposite sides of the top portion (4) , the transversal crossarms of the first set being configured to selectively receive, at their first end (12) , opposite to the body, first insulator suspension set (13) and second insulator tension set (14) for the support of said conductors;

- a second set of insulating transverse crossarms (15) that can be fixed laterally on opposite sides of the top portion (4) , the transverse crossarms of the second set being configured to support at their first end (16) , opposite to the body, said conductors (5) .

2. Modular system according to claim 1, characterized by the fact that said uprights (36) and transverse angles (20, 21 37) are arranged and configured to give the first reticular structure (38) a recursive configuration forming

25 a plurality of three-dimensional modules (8) identical to each other and arranged sequentially in the vertical direction (V) ; the modular system also comprising respective attachment elements (18; 19) arranged equally spaced apart in the vertical direction (V) between pairs of adjacent modules (8) and/or in correspondence of one or more modules, said attachment elements being configured to receive the transverse crossarms (10, 11) of the first and second (15) sets arranged in correspondence with the three-dimensional modules ( 8 ) .

3. Modular system according to claim 2, characterized by the fact that at least one first set of the said attachment elements (18) are configured to be fixed in correspondence with an upper or top end (20) and a lower or base end (21) of each three-dimensional module (8) forming the top portion (4) , so as to be equally spaced apart and such that at least part of the transversal crossarms of the first and second set (10,ll;15) can be fixed on the top portion (4) at any of the three-dimensional modules (8) formed by it.

4. Modular system according to one of the previous claims, characterized by the fact that the first set of transverse crossarms in lattice structure includes first crossarms (10) identical to each other and having the same transverse overhang from the top portion (4) and second crossarms (11) having a transverse overhang from the top portion (4) greater than that of the first crossarms.

5. Modular system according to one of the previous claims, characterized by the fact that it also comprises a set of first (22) , second (23) , third (24) and fourth (25) brackets selectively fixable each to the top portion in correspondence of one or more of said three-dimensional modules (8) in which it is divided to constrain laterally to the same a respective insulating transverse crossarm (15) of the second set of transverse crossarms; the first and second brackets (22,23) being configured to be fixed at an upper attachment point (26) of each insulating transverse crossarms (15) at, respectively, a first and a second prefixed transversal distance from the top portion (4) , the second prefixed distance being greater than the first prefixed distance.

6. Modular system according to claim 5, characterized by the fact that the first and second brackets (22,23) are formed by two angle elements (27,28) connected together at a first end (29) thereof and connected to respectively an upper end (20) and a lower end (21) of a three-dimensional module (8) so as to form with it, in an elevation frontal view, an isosceles triangle; the first and second brackets (10,11) being configured to extend overhanging from the top portion (4) , the second brackets (11) with an overhang greater than that of the first brackets (10) .

7. Modular system according to claim 5 or 6, characterized by the fact that the third brackets (24) are configured to be fixed to a lower attachment point (32) of each transversal insulating crossarm at a third prefixed transversal distance from the top portion, smaller than the second prefixed distance, in pair with one said second bracket (23) bound to the upper attachment point (26) of the same insulating transverse crossarm (15) ; the third brackets (24) being configured to extend overhanging from the top portion (4) with an overhang smaller than that of the second brackets (23) and being formed by two angle elements (33) connected together by a first end (34) thereof and connected to respectively an upper end (20) and a lower end (21) of a three-dimensional module (8) so as to form with it, in a front elevation view, a rectangular triangle.

8. Modular system according to one of the claims from 5 to 7, characterized by the fact that the fourth brackets (25) are configured to be fixed to a lower attachment point (32) of each insulating transverse crossarm, in pair with one said first bracket (22) constrained to the upper attachment point (26) of the same insulating transverse crossarm (15) ; the fourth brackets (25) being made of elements made of profiles (35) shaped like a U arranged horizontally and fixed to a lower end (21) of the three- dimensional modules.

9. Modular system according to one of the previous claims, characterized by the fact that it also comprises a set of three-dimensional reticular point-shaped end elements or earth wire peaks (9b, 9c) , of pyramidal shape, configured to be fixed in an integral way to the top of the top portion (4) and having at least two different heights.

10. Modular system according to one of the previous claims, characterized by the fact that said uprights (36) and transverse angles (20, 21, 37) forming the top portion (4) subdivided into said three-dimensional modules (8) are configured to be fixed in an integral way to one another, constrained together and with the transverse crossarms (10, 11; 15) of the first and second set by means of bolted metal plates; said bolted metal plates also acting as points or knots of attachment (18) for said crossarms (10, 11, 15) .

11. Method to realize a lattice tower, particularly for a high-voltage overhead electrical transmission line, including a base (2) , which can be anchored to the ground, and a body (3) ending, at the side opposite to the base, with a modular top portion (4) and configured to fasten the respective conductors (5) of said electrical transmission

28 line, characterized by the fact that it comprises the following steps: realizing a first truncated-pyramidal reticular structure (7) forming the body;

- realizing a second straight and parallelepiped-shaped reticular structure (38) overhanging the truncated-pyramidal body (7) and constituting at least part of said top portion (4) using four straight uprights (36) having a first prefixed length, the straight uprights being configured to be connected to each other with a plurality of angles (20, 21, 37) arranged transversely to the uprights and to be fixed in a vertical direction (V) and parallel to each other on the first reticular structure (7) , so that the top portion (4) presents a prefixed recursive configuration forming a plurality of three-dimensional modules (8) identical to each other arranged sequentially in the vertical direction (V) ;

- selectively and laterally fixing on opposite sides of the top portion a first set of transversal crossarms (10,11) made of reticular structure or a second set of insulating transverse crossarms (15) , the transversal crossarms of the first set being configured to selectively receive, at their first end (12) , opposite to the body, first insulator suspension set (13) or second insulator tension set (14) for the support of said conductors; and the insulating transverse crossarms (15) of the second set being configured to support at their first end (16) , opposite to the body, said conductors ;

- the transversal crossarms of the first and second set (10, 11; 15) being fixed on the top portion at different heights and/or with different overhangs from the top portion, alternately or in pairs on both sides of the top portion, in order to selectively obtain a lattice tower for high-voltage

29 overhead power lines having different voltage levels, or of the Single-Circuit or Double-Circuit type, as well as in plain or mountain configuration.

12. Modular lattice tower to realize an overhead transmission line, particularly in high-voltage, with variable multi-purpose arrangement and comprising a base (2) , which can be anchored to the ground, and a body (3) of truncated-pyramidal shape (7) ending, at a side opposite to the base (2) , with a top portion (4) configured to connect, in suspension rather than in tension, respective conductors (5) of said high-voltage overhead transmission line; characterized by the fact that said top portion (4) is a single, reticular and rectilinear structure, formed by at least four straight uprights (36) of prefixed length and by a plurality of angles (20, 21, 37) arranged transversely to the uprights (36) and apt to connect the uprights to each other in a vertical direction (V) and parallel to each other, geometrically dividing the top portion according to a recursive configuration of shape, where said recursive configuration of the top portion is such as to: form a plurality of three-dimensional modules (8) identical to each other arranged sequentially in the vertical direction (V) , and allow the attachment of a plurality of mechanical appendages or transverse crossarms (10, 11, 15) for connecting the conductors (5) , so as to create a tower with a variable arrangement such as to implement different possible electrical geometries, thus providing a multi-role solution for the high-voltage infrastructure line.

13. Lattice tower according to claim 12, in which said plurality of transverse crossarms comprises first crossarms with reticular structure (10,11) or second insulating

30 crossarms (15) , which can be fixed laterally on opposite sides of the top portion (4) , the first transverse crossarms (10,11) being configured to selectively receive, at one end (12) thereof, opposite to the body, first insulator suspension set (13) and second insulator tension set (14) for the connection of the conductors (5) ; said second transverse crossarms (15) being configured to support at their first end (16) , opposite to the body, said conductors (5) .

31

Description:
"MODULAR LATTICE TOWER TO BUILD A HIGH VOLTAGE AERIAL

ELECTRIC TRANSMISSION LINE , WITH VARIABLE MULTI-PURPOSE

ARRANGEMENT , ITS MODULAR SYSTEM AND METHOD OF CONSTRUCTION"

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no . 102020000030587 fi led on December 11 , 2020 , the entire disclosure of which is incorporated herein by reference .

TECHNICAL SECTOR OF THE INVENTION

The present invention relates to an innovative modular lattice tower to realize a high-voltage overhead transmission line with variable multi-purpose arrangement , where the term "high voltage" is to be understood as a range of voltage values defined by the standard of reference , in particular by EN 50341 - 1 , where this standard covers the design and reali zation of overhead electrical lines with rated voltage greater than I kV .

The present invention also relates to the correlated, and still innovative , modular system to reali ze the aforesaid lattice tower, capable of satis fying various configuration requirements with a minimum number of components .

Finally, the present invention relates to an innovative method to reali ze , or modi fy in situ, a modular lattice tower for high-voltage overhead power lines with variable multipurpose arrangement .

BACKGROUND ART

The Applicant , in his capacity as a manager of a High Voltage (HV) Electricity Grid, has the need to reali ze and/or adapt high-voltage overhead lines that reach di f ferent types of territory and that allow the transmission of electricity at di f ferent transport voltages , also depending on the distances covered and on the electrical management of such portions of the Grid ( typically 66kV and 132- 150kV) , as well as to connect Active and Passive Users who request connection to the HV Electricity Grid, all in accordance with the best principles of economic and environmental sustainability of the works , finally facilitating, as far as possible , the construction of the HV supports , also with reference to the resilience of the electrical infrastructure .

These needs are only partially met by the lattice towers currently in use .

They consist in fact of reticular structures comprising a base anchored to a foundation structure , for example consisting of one or more reinforced concrete plinths embedded at least partially in the ground, and a lattice body ending with a portion of the structure ( the so-called "pole head" , also referred to hereinafter simply as the "top portion" ) to which, by means of special reticular appendages ( transverse crossarms ) and chains of insulators or with insulating appendages ( insulating crossarms ) , the HV (high- voltage ) energy conductors are mechanically connected, constituting the three-phase HV line to be supported, which may be a three-conductor line , known as a "Simple Circuit" or SC, or a six-conductor line ( known as a "Double Circuit" or DC ) and which performs the functions of a double three- phase transport line for the transmission of electricity . The "pole head" f inally culminates in one or more reticular structures called "earth wire peaks" to which one or more ground wires are connected .

The chains of insulators that bind the electrical conductors are generally supported by transverse crossarms , e . g . made with a reticular structure , fixed transversely on the pole top portion, or they can depart directly from the pole head, forming insulating crossarms, also fixed transversely to the pole top portion.

Typically, in the towers of overhead power lines, the body and the top portion are generally realized as a single truncated-pyramidal reticular structure, the top of which, overlying the energy conductors and the relative support crossarms, receives a pointed end element, the so-called "earth wire peak", pyramidal in shape, having a designed end vertex to which the ground wire is connected, also commonly referred to as the "ground line".

Depending on the type of territory crossed by the HV electrical transmission line (e.g. plain or mountain) and on the type of electrical transmission line (SC or DC, and at 66 or 132-150kV) the tower takes on different shapes and sizes, making the individual towers non-interchangeable and, often impossible to adapt in the case of switch to the configuration with insulating crossarms, switch from the lower 66kV to the higher 132-150kV voltage level, or when switching from the traditional crossarms to the insulating crossarms and, again, from the configuration for "plain" arrangement to the configuration for "mountain" arrangement, which differs in the vertical offset of the conductors.

Prefabricated towers that can be used for emergency repairs of an HV electrical transmission line are also known from WO2014/153962. These prefabricated towers are formed entirely by the mutual joining of self-supporting cubic reticular modules, mounted superimposed. Such prefabricated towers are relatively expensive, relatively unstable and are only suitable for temporary use, i.e. only for carrying out emergency repairs.

OBJECT AND SUMMARY OF THE INVENTION

Aim of the present invention is therefore to overcome, or at least alleviate , the problems outlined above and to allow to reali ze the lattice towers relatively quickly and at low cost , especially for high-voltage overhead transmission lines , with variable multi-purpose arrangement , i . e . which are suitable to satis fy all types of use , particularly in the high-voltage field and essentially without modi fications or with minimal prior modifications of the body .

In this respect , the invention relates to the modular system to reali ze a lattice tower, as well as to the HV lattice tower obtainable with the modular system of the invention, as well as to the method to reali ze , or modi fy in situ, a lattice tower for high-voltage overhead power lines , as defined in the appended claims .

In greater detail , the lattice tower of the present invention has a base , which can be anchored to the ground, a truncated-pyramidal body and a top portion configured to connect , in suspension rather than in tension, respective conductors of a high-voltage overhead electrical transmission line ; the top portion is a single , reticular and rectilinear structure formed by at least four straight uprights of prefixed length and by a plurality of angles arranged transversely to the uprights connecting them in a vertical and parallel direction . In this manner, the top portion remains geometrically divided in order to define a recursive configuration of shape , in which the recursive configuration of the top portion is such as to :

- form a plurality of three-dimensional modules ( 8 ) identical to each other arranged sequentially in the vertical direction (V)

- be prepared for the attachment of the various mechanical appendages or transverse crossarms . Thanks to this configuration, the single top portion and the relative crossarms are suitable for creating a tower support with variable arrangement such as to implement different possible electrical geometries and thus have a multi-role solution that is:

- Operable at different voltage levels (e.g. 66kV and/or

132-150kV) ,

- Flexible to the evolution of the localization context of the work such as anthropized areas (problems of exposure to electric and magnetic fields) , or areas with the presence of constraints (of a landscape nature, or risk of bird collisions) ,

- Resilient in different climatic and orographic conditions (plain or mountain arrangement) .

In this way, towers of different shapes and sizes, interchangeable and/or adaptable, can be obtained, in particular in the case of:

- switch to different voltage levels, for example from a lower voltage level of 66kV to a higher voltage level of 132-150kV,

- switch from traditional crossarms to insulating crossarms ,

- switch from the configuration with "plain" arrangement to the configuration with "mountain" arrangement, which differs in the vertical offset of the conductors .

Moreover, the aforesaid multi-disciplinary feature of the lattice tower of the invention allows for adaptations and/or modifications even during operation of the power line.

The modular system of the invention also comprises a first set of transversal crossarms made of reticular structure and a second set of insulating transverse crossarms , of known type , which can be selectively fixed on opposite lateral transverse faces of the top portion, at di f ferent heights , for example in correspondence with single three-dimensional modules spaced vertically from each other by means of other three-dimensional modules without transverse crossarms .

The transverse crossarms of the first set are configured to selectively receive , at a first end thereof , opposite the body, first insulator suspension set or second insulator tension set for the support of the conductors .

On the other hand, the insulating transverse crossarms of the second set are configured to directly support the conductors of the HV power line at a first end thereof , opposite the body .

In this way, by means of a standard structure , it is possible to support the conductors at di f ferent vertical distances in order to meet the di f ferent requirements for the transport of high-voltage electricity, particularly either at 66kV or 132- 150kV, while respecting the standard electrical distances , which vary with the rated voltage of the power line .

The first set of transverse crossarms in lattice structure then includes first crossarms identical to each other and having the same transverse overhang from the top portion and second crossarms , also generally identical to each other, having a transverse overhang from the top portion greater than that of the first crossarms .

In accordance with a further aspect of the invention, for each set of crossarms there is /are also provided one or more crossarms with increased transverse overhang; it is thus possible to modulate the type of obtainable tower, configuring the lattice for di f ferent rated voltage levels , for example a first voltage level at 66kV ( first set of crossarms ) or a second level at 132 - 150kV ( second set of crossarms ) as well as for installation in the plain, where the conductors can be arranged at the same transverse distance (by virtue of the use of crossarms with the same transverse overhang) or for installation in the mountain, where the conductors underlying other conductors must be arranged transversely staggered from each other, so that adj acent conductors are not on the same vertical (by virtue of the use of one or more crossarms with an increased transverse overhang compared to the others ) .

The installation in the plain as well as in the mountain for the voltage level 132 - 150kV is also obtainable with the second set of insulating transverse crossarms , which are all identical to each other .

In such a case , the modular system of the invention further comprises a set of first , second, third and fourth brackets selectively fixable to the top portion, each in correspondence of one or more of the three-dimensional modules in which it is divided to constrain lateral ly to the same a respective insulating transverse crossarm .

The first and second brackets are configured to be fixed at a higher attachment point of each insulating transverse crossarm at , respectively, a first and a second prefixed transversal distance from the top portion, the second prefixed distance being greater than the first prefixed distance .

In fact , the first and second brackets are configured to extend overhanging from the top portion, the second brackets with an overhang greater than that of the first brackets .

According to a preferred, but not limiting, embodiment , the first and second brackets are formed by two angle elements , e . g . reticular, connected together at a first end thereof and connected at the other end to respectively an upper end and a lower end of a three-dimensional module so as to form with it , in an elevation frontal view, an isosceles triangle .

The third brackets , on the other hand, are configured to be fixed to a lower attachment point of each transversal insulating crossarm in order to ensure its attachment to the tower at a third prefixed distance from the top portion, in pair with one second bracket bound to the upper end of the same insulating transverse crossarm .

According to a preferred, but not limiting, embodiment , the third brackets are configured to extend overhanging from the top portion with an overhang s lightly smaller than that of the second brackets and are formed by two angle elements , e . g . reticular, connected together at a first end thereof and connected at the other end thereof to respectively an upper end and a lower end of a three-dimensional module so as to form with it , in a front elevation view, a rectangular triangle .

Finally, the fourth brackets are configured to be fixed to a lower attachment point of each insulating transverse crossarm, in pair with a first bracket constrained to the upper end of the same insulating transverse crossarm .

According to a preferred, but not limiting, embodiment , the fourth brackets are constituted by attachment feet shaped like a U arranged hori zontally and facing the side opposite to the tower, fixed to a lower end of the three-dimensional modules .

Finally, the transverse crossarms can be fixed to the three-dimensional modules of the top portion in alternately opposite lateral positions along the vertical of the tower for SC supports or in pair of crossarms placed at the same height from the ground, extending overhanging from both opposite sides of the top portion and which are arranged in pair below the other for DC supports , in correspondence of suitably configured three-dimensional modules .

The modular system according to the invention preferably also comprises respective attachment points for the transverse crossarms of the first and second set arranged in correspondence with the three-dimensional modules , preferably at an upper end, or top , and a lower end, or base , of each three-dimensional module .

Lastly, the modular system according to the invention comprises a set of three-dimensional reticular point-shaped end elements or earth wire peaks , of pyramidal shape and square base , configured to be fixed in an integral way to the top of the top portion and having at least two di f ferent heights , so as to selectively reali ze lattice towers for power lines of 135- 150kV with the earth wire peaks at higher height or 66kV with the earth wire peaks at lower height .

According to a possible embodiment , the three- dimensional modules can be configured to be reali zed in an integral way with each other so that the upper end of one module constitutes the lower end of another immediately overlying module .

Suitably bolted metal plates are preferably used to constrain the components of the three-dimensional modules together, i . e . the reticular structure and the transverse crossarms .

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the present invention, some preferred embodiments thereof , provided for merely exemplary and non-limiting purposes will now be disclosed with reference to the attached drawings (not in a scale ) , wherein :

• Figures 1 to 4 show di f ferent types of modular towers , i . e . Single-Circuit suspension and tension as well as Double-Circuit suspension and tension, all of which can be reali zed according to the gist of the invention, in particular by means of attachments of special reticular appendages represented with a thicker blackcoloured line ; the modular tower can thus be used in a versatile manner and in particular for the renewal of HV overhead power lines (with general reference to power lines from the 1920s to the 1950s ) , through an environmentally sustainable solution, either on a 66kV overhead line with Traditional Crossarms , or on a 132- 150kV overhead l ine with Traditional or Insulating Crossarms , as well as in the hypothesis of a line initially at 66kV that needs upgrading to a higher voltage level ( 132 - 150kV) , following the rationalisation of portions o f the electricity grid;

• Figure 5 shows one of the modular towers which can be reali zed according to the present invention, shown without the relative crossarms ; the tower compri ses , in particular, a single reticular bearing structure , called top portion, with parallel faces , characteri zed by the repetitiveness of a parallelepiped shape ;

• Figure 6 shows the respective top portions of the various types of tower considered, i . e . as a Single- or Double-Circuit , and with connection of the conductor in Suspension or Tension .

• Figures 7 to 14 show, schematically and in a lateral elevation view, lattice towers for overhead power lines of the Single-Circuit type , according to the invention, for which, for simplicity of exposure , only an upper part of the body is shown in detail , including the top portion, and in which the components which can be selectively used from time to time are shown with a more marked line ;

• Figure 15 shows , on an enlarged scale , the details A) , B ) , B' ) , C) and D) of the connection of traditional crossarms to the Single-Circuit towers referred to in Figures 7 to 14 ;

• Figures 16 to 23 show, schematically and in a lateral elevation view, di f ferent types of lattice towers for overhead power lines of the Double-Circuit type , according to the invention, for which, for simplicity of exposure , only an upper part of the body is shown in detail , including the top portion, and in which the components which can be selectively used from time to time are shown with a more marked line ;

• Figure 24 shows , on an enlarged scale , the details A' ) , B' ) , B" ) C ) , D) and D' ) of the connection of traditional crossarms to the Double-Circuit towers referred to in Figures 15 to 23 ;

• Figures 25 to 28 show, schematically and in a lateral elevation view, respective types o f lattice tower for overhead power l ines with insulating crossarms , for which, for simplicity of exposure , only an upper part of the body is shown in detail , including the top portion, and in which the components which can be selectively used from time to time are shown with a more marked line ;

• Figure 29 shows , on an enlarged scale , the details D) , E ) , F) , G) , H) and I ) of the connection of the insulating crossarms to the Single- and Double-Circuit towers referred to in Figures 25 to 28 ;

• Figures 30 to 33 show, in schematic form, the operating instructions for carrying out the various trans formations and obtaining the towers referred to in the previous figures .

DETAILED DESCRIPTION

The following description is provided to enable a person skilled in the art to reali ze and use the invention, which protecs both the lattice tower and the respective modular system .

Various modi fications to the embodiments set forth will be immediately clear to the persons skilled in the art and the general principles herein disclosed may be applied to other embodiments and applications without , however, departing from the protection scope of the present invention as defined in the enclosed claims .

With reference to the Figures , reference number 1 denotes a lattice tower for high-voltage (HV) overhead power lines having a lattice structure which can be anchored to the ground by means of , for example , a base 2 and a body 3 ending, at the side opposite to the base 2 , with a top portion 4 designed to connect , in suspension rather than in tension, respective conductors 5 o f a high-voltage overhead transmission line , known and not shown in detail for simplicity .

Speci fically, the top portion 4 of the lattice tower 1 is reali zed with the modular system according to the invention . In fact , this modular system comprises , and is therefore defined by :

- a truncated-pyramidal reticular structure 7 forming, in whole or in part , the body 3 ,

- at least four straight uprights 36 ( Figure 5 ) having a first prefixed length, substantially equal to a desired useful height for the top portion 4 of a lattice tower configured for a power line of , for example , 66kV or 132- 150kV .

The straight uprights 36 are configured to be connected ( and are connected, in the tower 1 ) to each other with a plurality of angles 20 , 21 , 37 arranged transversely to the uprights and are configured to be fixed in a vertical direction V and parallel to each other on the first reticular structure 7 , so as to form a single straight reticular structure 38 of parallelepiped shape, overhanging the body 3 , which in turn is formed by the first truncated-pyramidal reticular structure 7 .

The uprights 36 and the respective transverse angles 20 , 21 37 are configured to give the reticular structure 38 defining the top portion 4 , a prefixed recursive configuration which, as a whole , forms a plurality of three- dimensional modules 8 identical to each other and arranged sequentially in the vertical direction V .

In more detail , the three-dimensional modules 8 are reali zed by assembling the uprights 36 with :

- Pairs of angles 37 bolted at the ends , and mutually arranged crosswise , to the uprights , i . e . to cover all four faces of the single module 8 ,

- Upper and lower partition elements , such as those indicated with 20 and 21 and arranged hori zontally with respect to the vertical direction V of the top portion 4 of the lattice support 1 , so that a module 8 , which is formed by four elements 20 and the same many elements 21 , shares with the adj acent module the relative partition .

In accordance with an aspect of the invention, the modules 8 in which the recursive geometry top portion 4 can ideally be divided can have a cubic or parallelepiped shape.

The modular system, and thus also the tower, also comprises a set of known three-dimensional reticular pointshaped end elements 9b, 9c, known as "earth wire peaks" (Figures 7 and 8) , of pyramidal shape and with square base.

The set of end elements 9b, 9c may comprise, for example, two (or more) different types of earth wire peaks, all configured to be fixed in an integral way with a respective three-dimensional module 8b arranged at the top of the top portion 4 and having at least two different heights, for example a "short" earth wire peaks 9b having a simple tetrahedral or reticular structure and an earth wire peak 9c, which is higher than the earth wire peak 9b and always having a reticular structure. The height of the earth wire peaks 9b, 9c is chosen according to the rated electrical voltage of the HV overhead line, e.g. the shorter earth wire peaks 9b can be used on 66kV lines, while the taller earth wire peaks 9c can be used on 132-150kV lines.

The modular system also comprises a first set of transverse crossarms 10 and 11 made of reticular structure, for example, in a known way and therefore not described in detail, and which can be fixed laterally on opposite lateral transverse faces of the top portion 4.

Both types of transverse crossarms 10 and 11 of the first set are configured to selectively receive, at a first end 12 thereof, opposite the body 3, each a suspension insulator 13 (of known type) or tension insulators 14 (also of known type) for the support of the conductors 5.

In particular, among the cited first set of transverse crossarms 10, 11 in reticular structure, the first crossarms 10 are identical to each other (in terms of electrical voltage level ) and have the same overhang or transverse overhang from the top portion 4 , while the second crossarms 11 have an overhang or transverse overhang from the top portion 4 greater than that of said first crossarms 10 .

These crossarms 10 , 11 may be variously combined in number and arrangement on the same top portion 4 to obtain in a modular way di f ferent types of lattice towers 1 .

The modular system further comprises a second set of insulating transverse crossarms 15 ( Figures 25 and 26 ) , of known type , which can be fixed laterally, in the way that will be seen later, on the opposite transverse faces of the top portion 4 , which crossarms 15 are configured to support directly and in a known way, at a first end thereof 16 opposite the body 3 , the conductors 5 .

The aforesaid crossarms 15 , together with further components of the modular system which will be described below, can be used in place of the crossarms 10 , 11 and the corresponding suspension 13 or tension 14 insulators , so their mounting on the top portion 4 is normally alternative to the use of the crossarms 10 , 11 .

The modular system according to the invention further comprises respective points or knots of attachment 18 for the transverse crossarms 10 , 11 of the first set and for the crossarms 15 of the second set .

The aforesaid points or knots of attachment 18 are conveniently arranged at the lower and upper end of the recursive shape identi fying the three-dimensional modules 8 .

Thus , the aforesaid points or knots of attachment 18 are arranged in the direction V between pairs of three- dimensional modules 8 .

In other words , the aforesaid points or knots of attachment 18 are in correspondence with the knots of the reticular structure 38 forming the sequence of individual three-dimensional modules 8 . It follows that said aforesaid points or knots o f attachment 18 are obtained as integral parts of the reticular structure 38 and of each module 8 and are configured in correspondence o f an upper end, or top 20 , and of a lower end, or base 21 , of each module 8 , so that at least part of ( or all ) the transverse crossarms 10 , 11 of the first set and the transverse crossarms 15 of the second set may be fixed to the reticular structure 38 o f the top portion 4 in correspondence of any of the three-dimensional modules 8 .

Advantageously, the reticular structure 38 also includes points or knots of attachment 19 , apt to form a second set of attachment points for the crossarms 11 , i . e . those with increased length with respect to the crossarms 10 ; said points or knots 19 are substantially allocated in the centre line of one or more modules 8 , i . e . formed arranged between their ends 20 and 21 , with the advantage of being able to fix crossarms , in particular the aforesaid crossarms 11 partly on a first module 8 and partly on another immediately overlying module 8 .

According to an aspect of the invention, crossarms 10 , 11 can be fixed to the top portion 4 , at the height of di f ferent modules 8 of the reticular structure 38 in alternately opposite lateral pos itions to obtain SingleCircuit towers . Alternatively, the crossarms 10 , 11 may be fixed on the top portion 4 and in pairs side by side , on the opposite transverse faces of a single module 8 and below, arranged at di f ferent heights , to obtain a Double-Circuit tower 1 .

The crossarms 10 and/or 11 extend overhanging from the opposite transverse faces , starting from both opposite sides of the top portion 4 and are arranged one below the other, in correspondence of three-dimensional modules 8 between which at least one three-dimensional module 8 without crossarms is preferably arranged, so as to be vertically spaced apart from each other by a prefixed and adj ustable quantity based on the number of modules 8 without crossarms 10 , 11 being reali zed .

Also the insulating crossarms 15 of the second set of crossarms can be mounted on the top portion 4 with configurations similar to that described for the crossarms 10 , 11 .

For this purpose , the modular system also comprises a set of first brackets 22 , second brackets 23 , third brackets 24 and fourth brackets 25 , each of which can be selectively fixed to the top portion 4 in correspondence of one or more of the three-dimensional modules 8 in which the top portion 4 is divided, in order to laterally bind to the same a respective insulating transversal crossarm 15 of the second set of transversal crossarms , which is thus connected to the top portion 4 , in correspondence of the modules 8 with interposition of a pair of brackets 22 , 25 or 23 , 24 .

The first and second brackets 22 , 23 are configured to be fixed to an upper attachment point 26 of each insulating transverse crossarm 15 at , respectively, a prefixed first and second transverse distance from the top portion 4 , the second prefixed distance being greater than the first prefixed distance .

For this purpose , the first and second brackets 22 , 23 are formed, each, by two angle elements 27 and 28 , for example of the reticular type or made of profiles , connected to each other at their first end 29 and connected to respectively the upper end 20 and the lower end 21 of a three-dimensional module 8 so as to form with it, in an elevation frontal view, an isosceles triangle.

In particular, the angle elements 27, 28 are connected to the knots 18, which also connect together the three- dimensional module 8 to which the angle elements 27,28 are connected with two other modules 8, arranged above and below it, respectively. The ends 29 are in turn connected by a knot 30, for example consisting of a side-by-side pair of bolted plates 31.

The only difference between brackets 22 and 23 consists in the different length of angle elements 27,28, where shorter angle elements 27b, 28b are used for the bracket 22, and longer angle elements 27c, 28c are used for the bracket 23, so that the angle formed by the junction of the elements 27c, 28c (e.g. about 30°) is less than that formed by the junction of the elements 27b, 28b (slightly more than 90°) .

In any case, thanks to the different length of the elements 27b, c and 28b, c the first and second brackets 22,23 are both configured to extend overhanging from the top portion 4, but the second brackets 23 with an overhang greater than that of the first brackets 22.

Similarly, the third brackets 24 are configured to be fixed to a lower attachment point 32 of each insulating transverse crossarm 15 but at a third prefixed distance from the top portion 4, less than the second prefixed distance, in pair with a respective second bracket 23 constrained to the upper end 26 of a same insulating transverse crossarm 15.

The third brackets 24 are configured to extend overhanging from the top portion 4 with an overhang lower than that of the second brackets 23 and are formed by two angle elements 33, for example reticular or made as profiles, connected together at their first end 34, e.g. as the angle elements 27,28, and connected to the knots 18 of, respectively, the upper end 20 and the lower end 21 of a three-dimensional module 8, so as to form with it, in a front elevation view, a rectangular triangle.

The brackets 23,24, having an overhang length greater than the brackets 22, allow the position of the lower insulating crossarm 15 (and consequently of the conductor 5 associated with it) to be offset laterally, allowing snow to fall more easily in mountain areas without overloading the conductors 5.

The fourth brackets 25 are also configured to be fixed to the lower attachment point 32 of each insulating transverse crossarm 15, but in pair with a respective first bracket 22 constrained to the upper end 26 of the same insulating transverse crossarm 15.

The fourth brackets 25 are made of elements shaped like a U arranged horizontally and facing the side opposite to the support 1, for example formed by a U-shaped profile 35, fixed to a corresponding knot 18 of the lower end 21 of the three-dimensional modules 8.

It is evident that in the attached Figures, which are views in orthogonal projection and in elevation of the top portions 4 and of the relative modules 8, only a single knot 18 is visible for each angle of the rectangle (in the figure) formed by each module 8, but that another knot 18 is arranged behind the one visible in the relative Figures, at a distance corresponding to the transverse width of its faces, measured in a direction perpendicular to the plane of the sheet, of each module 8, so that the brackets 22-25 will be connected to both such knots 18, or to a crossbar connecting them to each other. Preferably, the uprights 36 and the transverse angles 20 , 21 , 37 forming the top portion 4 divided into the three- dimensional modules 8 are configured to be fixed in an integral way one with the other constrained between them and with the transverse crossarms 10 , 11 ( in a direct manner ) of the first set and with the insulating transverse crossarms 15 ( in an indirect manner ) of the second set through the knots 18 , for example made in a traditional manner with bolted metal plates .

It is evident from what has been described so far that all the variants of the lattice tower shown in the figures can be obtained by composing di f ferently the top portion 4 , the earth wire peaks 9 and the crossarms 10 , 11 or the brackets 22-25 for the crossarms 15 .

Finally, it is apparent that the invention also extends to a method to reali ze a lattice tower for high-voltage overhead power lines having a lattice structure including a base 2 anchored to the ground and a body 3 ending, at the side opposite to the base 2 , with a top portion 4 designed to fasten respective conductors 5 of a high-voltage overhead electrical transmission line , comprising the following steps : reali zing a first truncated-pyramidal reticular structure 7 forming at least part of the body 3 ;

- reali zing a second straight and parallelepiped-shaped reticular structure 38 overhanging the truncated-pyramidal body 7 and constituting almost all or all of the top portion 4 using four straight uprights 36 having a first fixed length, the straight uprights being configured to be connected to each other with a plurality of angles 20 , 21 and 37 arranged transversely to the uprights , and arranged to be fixed in a vertical direction V and parallel to each other on the first reticular structure 7 , so that the entire top portion 4 presents a prefixed recursive configuration forming a plurality of three-dimensional modules 8 identical to each other arranged sequentially in the vertical direction V; preferably, the number of modules 8 formed by the top portion 4 being smaller to reali ze a 66kV power line (by way of example ) and greater, so as to obtain a greater overall height of the top portion 4 , to reali ze a 132 - 150kV power line (by way of example ) ;

- selectively and laterally fixing on opposite sides of the top portion a first set of transversal crossarms 10 , 11 made of reticular structure or a second set of insulating transverse crossarms 15 , the transversal crossarms of the first set being configured to selectively receive , at their first end 12 , opposite to the body, first insulator suspension set 13 or second insulator tension set 14 for the support of the conductors 5 ; and the insulating transverse crossarms 15 of the second set being configured to support at their first end 16 , opposite to the body, the conductors 5 ;

- the transversal crossarms of the first and second set 10 , 11 or 15 being fixed on the top portion 4 at di f ferent heights and/or with di f ferent overhangs from the top portion, alternately or in pairs on both sides of the top portion, in order to selectively obtain a lattice tower for HV overhead power lines for di fferent rated voltage levels , rather than in Single-Circuit or Double-Circuit , as well as in plain or mountain configuration .

All the aims of the invention are therefore achieved .

With reference to figures 30 , 31 , 32 , 33 some examples are shown for the trans formation of the support , in particular the trans formation of a 66kV SC tension support to a 150kV SC tension support , with plain and mountain crossarms .

The first operation includes dismantling the 66kV earth wire peak and replacing it with the new earth wire peak for 150kV voltage , also dismantling the body attachment plates .

The second operation includes dismantling the 66kV high, medium and low crossarms and in more detail the respective attachment plates ( knots 18 ) of the tie rods of the crossarms .

The third operation follows , namely :

- The 150kV high crossarm is placed and mounted one module 8 above where the 66kV voltage crossarm was located . In greater detail , in this case the plates for the attachment of the tie rods also act as a j oint for the earth wire peak . The new attachment plate between the pole and the crossarm strut is also mounted .

- The 150kV medium crossarm is placed and mounted in place of the 66kV medium crossarm . Said 150kV medium crossarm includes new plates for tie rod attachment , which must replace the existing plates present on the body .

- The 150kV low crossarm is placed and mounted in place of the 66kV low crossarm, replacing the existing tie rods attachment plates with the new tie rod attachment plates .

Preferably, in correspondence with the attachment to the body of the struts of all the cros sarms , the existing bolts are replaced .

A fourth operation includes inserting the section rods at the level of the new high crossarm .

Again by way of example and with reference to the figures indicated above , another operating instruction is given, one that concerns the trans formation of an SC66kV suspension pole into an SC suspension pole with 150kV voltage , with plain and mountain crossarms .

The first operation consists in dismantling the 66kV earth wire peak and replacing it with the new earth wire peak for 150 kV voltage .

The second operation includes dismantling the high, medium and low, 66kV crossarms , including the tie rod attachment plates ( knots 18 ) for the medium crossarm and low crossarm . The tie rod plates for the high crossarm can remain in place .

A third operation concerns the 150kV high crossarm, which must be mounted two spans above where the high 66kV crossarm was located, whereas the 150kV medium crossarm must be mounted one span above the 66kV medium crossarm and the 150kV low crossarm must be mounted one span above the 66kV low crossarm .

In correspondence with the attachment to the body of the struts of all crossarms , the existing bolts are replaced with the new ones supplied .

The medium crossarm is supplied with new tie rod attachment plates which will have to replace the existing plates present on the body . The old tie rod attachment plates for the 66kV cros sarm will need to be replaced with the new strut attachment plates for the new crossarm .

It then remains to mount the new 150kV low crossarm, replace the existing tie rod attachment plates with the new strut attachment plates and the plates in the upper span with the new tie rod attachment plates .

The fourth operation includes inserting the section rods at the level of the new medium and low crossarms . It is important to note that, while the above described invention refers in particular to very specific embodiments, it must not be intended as limited to such embodiments, including within its scope all the variants, modifications or simplifications covered by the enclosed claims.

For example, although specific reference has been made in the description to 66kV or 132-150kV overhead electrical lines, these electrical voltage levels must not be construed as limiting the protection required; it is clear, in fact, that with the modular system described herein it is possible to effectively realize high-voltage overhead electrical lines of any rated voltage.