IES58406B2 - Improvements in apparatus for and method of powerline surveying, designing and maintenance - Google Patents

Abstract

Ground power line measuring device, comprising a measuring end is formed from the positions and positions of the vertical line outlet and connecting the computing device in the circuit and a point. The computing device capable of the is a landform segmented drawing according to the two infrared and three-dimensional form a logic circuit intersects. By two sets of Coordinate or a set of Coordinate and quadrant angle of the measuring scale along the power line of state. The part of the front and obtaining and a to the tape measure or a estimation of the data file. Lock and power line design on auxiliary device and selecting for measuring wire pike load of bearing the direction of the wire rod to provide conveniently.

Description

IMPROVEMENTS IN APPARATUS FOR AND METHOD OF POWERLINE SURVEYING, DESIGNING AND MAINTENANCE The present invention relates to an overhead powerline survey design method and in particular to a survey method for the and maintenance of overhead power lines, including survey of a line from points off the line so that the route of the line and the local topography line may be recorded.

Traditionally, surveying of existing powerlines or of the route of planned powerlines is restricted to exactly following the route of the powerline by sighting from one point on the line to the next, along the route of the line. The traditional methodology allows only very limited 2Q account to be taken of local topographical features, e.g. roads, houses and the like. Measurements taken in powerline surveys are generally recorded manually in a logbook and computed at a later time to derive two25 dimensional co-ordinates for the points measured, i.e. height and distance along the line. These co-ordinates are then plotted using traditional drafting techniques. If it is required to import this data into a computerised system, the transfer has to be done manually.

S58404 - 2 The positions of the required support structures for a proposed powerline may then be defined on this plot. Following this the line of the conductor is plotted and ground clearance checked. If sufficient clearance has been obtained, this design is accepted and the relevant materials ordered so as to construct it.

This paper based system has a number of inherent shortcomings . These are: - The whole design process takes place in two dimensions whereas in reality three dimensional data should be used.

- Modifying a proposed design is time consuming and costly.

- The whole process is slow.

- The transcription of data and manual computation of coordinates and draughting thereof is prone to error.

- The survey technique requires that a corridor along the proposed route be cleared completely of vegetation, so as to establish a clear line of sight.

- The survey technique does not take full account of features offset from the route of the line.

- The design process takes place in a scaled plot, not at actual scale, thereby introducing errors due to the poor definition of the features plotted.

- The conductors are modelled using fixed parameters.

These cannot be easily altered to take account of varying limits.

- The cost of the proposed line is not calculated until the design has been accepted.

The above disadvantages are overcome by the use of powerline surveying apparatus and methods disclosed in U.K. Patent Application No. 2 230 090A and U.S. Patent Application Serial Number 07/741114.

The powerline program described in these patent applications is a specialised program module that runs within any suitable program development environment such as that described in the invention disclosed in U.K. Patent Application No. 2202871A, entitled Method and Apparatus for Survey Datalogging, hereinafter referred to as Autograd.

The PowerLine survey system disclosed in U.K. Patent Application No. 2 230 090A and USSN 07/741114 is a suite of computer programs produced to assist in the design and maintenance of overhead power lines. It covers all aspects of the design process from the measurement of the initial ground profile under the proposed route through the definition of the exact support structure positions and conductor types, taking into account the predicted cost and the relevant safety standards and industry guide-lines, to ordering of the actual fittings required and checking the tension of the line at the final construction stage. An important feature of this suite of programs is that it does not finish on completion of the construction stage but also provides facilities whereby constructed lines may by subsequently checked both by visual inspection of the various fittings for depreciation or damage and also by re-survey if so required. Furthermore, it is not restricted to newly constructed lines but also provides facilities whereby existing lines may be surveyed and the existing support structures monitored, thereby bringing them into the system. All these functions are available 3θ within a single integrated suite of programs and are all referenced to a single data-base.

The field survey program permits the route of the line to be surveyed not only from positions actually on that route itself but also from other places remote from but referenced to the route of the line. This has not however prevented implementation of the traditional survey technique of passing height and distance information via a change point but rather has supplemented it by now permitting the full three dimensional position of the observing station to be computed in this manner. Further flexibility is given in that the traditional traversing technique of passing three dimensional position information directly from one station to the next is provided as an alternative method.

During field surveys the position of totally inaccessible points may be easily established utilising a technique new to powerline surveys of defining a vertical plane containing the required point using two easily accessible points and then sighting directly to the required point and computing its position.

For refurbishment surveys of existing powerlines the field survey programs can monitor existing support structures and check them against design data-base information while the surveyor is still in the field.

All positional data is recorded as three dimensional co-ordinates. Traditional two dimensional output may still be obtained however so as to provide compatibility with existing work practices and formats.

The survey data gathered using a field computer may be * θ passed either directly or via a storage medium to an office based design system. Each data point is incorporated in a data string and referenced to a specific feature type.

This means that when it is passed across to the office design system, the reception program can read this information and define it appropriately using data-base information. The reception program thus creates a data 2q file appropriate to the specified Computer Aided Design (CAD) system.

The support structure positions and types may then be added to this design file. These support structures are drawn from a library referenced directly to the data-base. This means that the exact dimensions, loadings, components and cost of each type of structure are immediately available.

Once the support structures have been planted the conductors may be modelled. To do this a special program has been written which takes the complex mathematical equations of the curves defined by the conductors and plots their positions. A shadow may also be plotted defining the 5 minimum clearance line thereby enabling ground clearance to be quickly checked. Some features (i.e. roads) require a greater clearance than this minimum distance. These clearances may be checked by the design engineer using the minimum distance function provided as standard by the host CAD system.

The conductor program holds data on all the conductor types available and permits the design engineer to select che most appropriate one. The design engineer may also alter I the equivalent span (related to the distance between tension points), operational temperature, ice loading and wind conditions thereby checking the ground clearance even in extreme conditions.

In further stages of the design process, the designed line is checked to ensure that it meets all the required safety standards, and the designed line may then be costed oxi the basis of the fittings required and the estimated construction costs. A list of the required fittings may then be produced so that they may be ordered.

If at any time during the design or checking procedure a change is made this is immediately reflected in the displayed plot and can quickly be checked for ground clearance, accordance with safety standards and costs.

A hard copy of the form of a fully annotated and properly presented drawing may be obtained at any time using the standard CAD system plot facility.

This plot may be passed to the engineer in charge of the construction process. The support structures may then be placed on this basis. The conductors may then be strung. In. order to check that the required tension is being correctly applied the conductor computations are also provided on the hand-held field computer. This enables the engineer to determine how far the line should sag (taking into account the currently existing temperature conditions) for the tension applied.

If at some later stage it is required to update the ground profile to take account of any changes in the local geography since it was constructed this may be quickly done using the same field survey system. The new survey may then be passed to the head office and overlaid over the original showing immediately any changes which have occurred. The effect of these changes are immediately revealed. Any resultant modifications may then be quickly determined and costed.

A further feature is that if at some stage a change is planned in the local geography (i.e. a new road is to be built or a local householder desires to build an extension) the effect of these changes may be determined prior to the actual construction taking place, and the proposed construction or the route of the line modified accordingly if this is significant.

For the continued maintenance of the line a Line Patrol program has been written for the field computer which 2θ permits updated information resulting from a visual inspection to be gathered. This data is added to the data-base as soon as it is returned to head office. The relevant repairs or points for further inspection or survey 25 may then not only be listed but their position may also be shown on an attached plot or plan saving substantial time at the repair stage.

Finally it is possible at the time of a re-survev to check the tension of the line on the spot using the Sag & Tension module. The clearance between any observed point (either at ground level or at some other height e.g. the top of a tree) may be checked without having to observe the line at all. Ά further benefit of this module is that where ground clearance is tight the clearance may be checked not only for the currently prevailing weather conditions but also for worst case situations. 0 The PoleLine and TowerLine suite o£ programs running on an office computer give the overhead line engineer all the tools needed to design and maintain overhead lines under one environment. The system is sufficiently open to allow the completed design to be passed to other departments for their modifications to be incorporated.

The package runs under a host CAD environment and Poleline/Towerline data and drawings can be transferred amongst individuals with no conversation processes i necessary and with no loss of information providing (they have access to a computer running the same CAD package, irrespective of hardware.

I The present invention provides improvements in powerline surveying, designing and maintenance within the framework of the system disclosed in U.K. 2 230 090A and US 07/741114. The improvements relate specifically to surveying steps carried out in the field and also to steps carried out during the graphics phase of powerline designing.

Accordingly, the present invention provides an apparatus for ground-based powerline surveying comprising means for measuring points off the route of a powerline in addition to points strictly along the route of the powerline, and means for preparing two and three dimensional representations of the line and the land surrounding it, whereby the ground profile beneath the powerline may be observed from locations referenced to, but not necessarily lying on, the actual route of the line itself, characterised in that there are provided means for measuring points a perpendicular distance from the line and means for linking the measured points together to form linear profiles at specified distances either side of the line .

Advantageously, the apparatus further comprises means for the two and three dimensional determination of a feature crossing the line by measuring the point of crossing and the angle or bearing at which the feature crosses the line and, optionally, the difference in height of the feature to either side of the line.

Preferably, the apparatus includes means for defining an alignment by measuring two sets of coordinates or one set of coordinates and a bearing and means for adding taped or estimated measurements to a line by reference to 'a previously measured point.

The present invention also provides a method of ground-based powerline surveying comprising measuring points off the route of a powerline in addition to points strictly along the route of the powerline, and preparing two and three dimensional representations of the line and the land surrounding it, characterised in that the method includes measuring points a perpendicular distance from the line and linking the measured points together to form linear profiles at specified distances either side of the line .

Advantageously, the method further comprises determining the two and three dimensional profile of a feature crossing the line by measuring the point of crossing and the angle or bearing at which the feature crosses the line and, optionally, the difference in height of the feature to either side of the line.

Preferably, the method includes defining an alignment by measuring two sets of coordinates or one set of coordinates and a bearing and means for adding taped or estimated measurements to a line by reference to a previously measured point.

The present invention further provides apparatus for powerline designing comprising means for measuring points off the proposed route of a powerline in addition to points strictly along the route of the powerline, means for preparing two and three dimensional representations of the proposed powerline and the land surrounding it, means for defining the conductor design of the proposed powerline in relation to its specific environment, means for comparing and checking the conductor design parameters against industry standards and means for identifying and specifying component requirements, characterised in that there are provided means for determining the loading on a conductor-carrying pole, «means for selecting a pole suitable for bearing the determined load and, optionally, means for adding at least one stay to support the pole and determined load.

The present invention still further provides a method of powerline designing comprising measuring points off the proposed route of a powerline in addition to points strictly along the route of the powerline, preparing two and three dimensional representations of the proposed powerline and the land surrounding it, defining the conductor design of the proposed powerline in relation to its specific environment, comparing and checking the conductor design parameters against industry standards and identifying and specifying component requirements, characterised in that the method includes determining the 10 loading on a conductor-carrying pole, selecting a pole suitable for bearing the determined load and, optionally, adding at least one stay to support the pole and determined load.

The invention will now be described more particularly with reference to the accompanying drawings in which: Figure 1 is a flow chart showing the steps in the side hill logging aspect of the field logging apparatus and method; Figure 2 is a flow chart showing the steps in the feature crossing aspect of the field logging apparatus and method; and Figure 3 is a flow chart depicting the stay module used in powerline designing.

Several new features have been added to the powerline program for use during a ground-based field survey. These are: 1. Alignment definition; 2. Side Hill logging; 3. Feature crossing; and 4. Taped Measurements.

These four aspects will now be described 1. Alignment Definition The previously described field, software considered each section of line as a separate unit. It then progressed to permit sequential sections to be linked together in one unit through recording the angle of deviation at each change of direction. To it has now been added another facility whereby an alignment may be defined by either two sets of coordinates, or one set of coordinates and a bearing. This allows the surveyor to change the start and/or end points of the survey and to redesign the position of the line, if necessary. Thus, if an error is found in a measured line, this can be corrected readily without re-measuring the line.

. Slide Hill Logging Referring to Figure 1, for each point measured along the alignment, the levels of points a specified perpendicular distance either, or both, sides of the line may be input. The ground modeller links these points together to form profiles the specified distance either side of the centre-line. These profiles may be used to determine clearances for the conductors. 3. Feature Crossing Referring to Figure 2, where a feature crosses the centre-line it may now be defined through measuring the crossing point and the angle or bearing at which it crosses the line. In addition to logging the crossing angle, the difference in height a specification distance left and right of the centre-line may also be logged thereby permitting the feature to be shown in full three dimensional form. If a vertical feature is being logged both the base and top of the feature are extended either side of the line. 4. Taped Measurements The facility has been added whereby taped or estimated measurements may be added to the date file, through specifying their distance, difference in height and bearing or angle relative to the line, from a previously measured point. A series of points may be measured in this manner, each determined relative to the previous one.

Referring now to Figure 3 and the table, another addition to the powerline suite of programe comprises a module for entering a stay or stays for a pole into a powerline design. i For each pole encountered the program determines the loading on it from all circuits, tee-offs and existing stays. It checks these against the database to see if any loads are violated. If these violations exceed safety limits it tries to select a suitably stronger pole from its library. If this does not remedy the situation it determines what, if any, stay configuration should be used.

All possible stay configurations for each type of pole are stored in a database file. This file holds the stay strength, the minimum/maximum number of stays allowed, the spread (for stay pairs) and the angle the stay makes with the pole. This information is stored for three different load conditions, transverse, longitudinal and resolved (transverse and longitudinal combined).

When a pole requires staying the stay configurations for that pole are read from the database file in sequential order until one is found which satisfies the loading Ω conditions. These stays are drawn graphically and added to the graphical model. The extra load imposed on the pole is then calculated and a warning given if the pole cannot withstand it.

Where there is a load out of balance and existing stays have been specified the program attempts to modify those stays that are considered to influence the imbalanced load At V (the stays directly behind the imbalance, and matched pairs behind the imbalanced load).

The table shows a typical printout from the stay module in the survey of 13 poles of a powerline. At each pole, the module assesses whether the pole strength is sufficient to the need. If not, a warning or error is signified and the programs recalculates using a stronger pole (see for example pole 3 calculation). If a sufficiently strong pole cannot be found, the program adds at least one stay. assign file is TEST Warning - no jobnane.pc file. Using first phase encountered.

Circuit 1 is phase Cl in file test.pci voltage 0.40 nuaber of phases 4 conductor λ.A. RAHCO Circuit 2 is phase C2 in file test.pc2 voltage 0.40 nusber of phases 4 conductor A. A. RASGO Warning - problems with file REH testl. ploads.dtb ploads.dtb poles.dtb poles.dtb pstays.dtb pstays.dtb For pole 1 at chainage .00 Pole type X1H11 Pole naae Analysis will ba botto® loading Listing of existing stays at this location: No. Naae Attach. Pt Stay angle Spread 7/7 7/7 9.00 45.00 100.00 9.00 45.00 *160.00 Circuit Vertical Longitudinal te® Transverse tea Resolved 1 .28 180.46 9.82 St. 1 9.67 -81.74 29.75 .00 13.67 16.00 OK St. 2 9.67 -81.74 29.75 .00 13.67 16.00 OK Total 19.61 16.98 9.82 19.61 Allowed 20.00 10.98 67.90 Ήβ Verdict OK OK OK OK Secoffisended pole is X1H11 - 20 For pole 2 at chainage 70.00 Pole type X1K11 Pole na>3 Analysis will be bottoa loading Circuit Vertical kN Longitudinal kite Transverse kits Resolved 1 .59 .00 39.94 Total .59 .00 39.94 39.94 Allowed 20.00 16.98 67.90 H/A Verdict OK OK OK OK Reconisended pole is X1H11 For pole 3 at chainage 150.00 Pole type X1H11 Pole naie Analysis will be botton loading Circuit Vertical kH Longitudinal kBa Transverse Ma; Resolved 1 .56 .00 76.53 Total <56 .00 76.53 76.53 Allowed 20.00 16.98 67.90 B'/A Verdict OK OK ERROR OK Using stronger pole X1S11 Allowed 20.00 33.95 135.80 »/A Verdict OK OK OK OK RecoEsaended pole is X1S11 For pole 4 at chainage 213.00 Pole type X1H11 Pole name Analysis will be bottos loading Circuit Vertical kB Longitudinal Mm Transverse Ms Resolved TABLJa ( Contd , ) 1 .57 .00 Total .57 .00 Allowed 20.00 16.98 Verdict OK OK Using stronger pole X1S11 Allowed 20.00 33.95 Verdict OK OK Recomended pole is X1S11 For pole 5 at chainage 295.00 Pole type xiHll Pole nane Analysis will be bottom loading Circuit Vertical M Longitudinal klfe! 1 .63 .00 Total .63 .00 Allowed 20.00 16.98 Verdict OK OK Recomended pole is X1H11 For pole 6 at chainage 372.00 Pole type X1H11 Pole naae Analysis will be bottom loading Circuit Vertical Longitudinal kH kHii 1 .64 .00 Total .64 .00 Allowed 20.00 16=98 Verdict OK OK Recoaaended pole is X1H11 For pole 7 at chainage 457.00 89.21 89.21 89.21 67.90 If/A ERROR OK 135.80 H/A OK OK Transverse kl’Ta! Resolved 22.31 22.31 22.31 67.90 H/A OK OK Transverse & Resolved 22.73 22.73 22.73 67.90 H/A OK OK x TABLE {Contd- ) Pole type X1H11 Pole nane Analysis will be bottosi loading Circuit Vertical kH Longitudinal kBn Transverse kite Resolved 1 .66 .00 23.43 Total .66 .00 23.43 23.43 Allowed 20.00 16.98 67.90 0/A Verdict OK OK OK OK RecoKnended pole is X1N11 For pole 8 at chainage 539.00 Pole type X1M11 Pole na’^e t ' Analysis will be bottos loading Circuit Vertical KI Longitudinal kite Transverse Ku Resolved 1 .69 .00 24.56 Total .69 .00 24.56 24.56 Allowed 20.00 16.98 67.90 B/A Verdict OK OK OK OK Recomended pole is X1H11 For pole 9 at chainage 632.00 Pole type XUill Pole naae Analysis will be bottoa loading Circuit Vertical k£ Lonuitudinal Transverse Resolved 1 .70 .00 24.84 Total .70 .00 24.84 24.84 Allowed 20.00 16.98 67.90 B/A Verdict OK OK OK OK Recomended pole is X1H11 TABUS (contd.) For pole 10 at drainage 716.00 Pole type X1E11 Pole na®e Analysis will be bottom loading Listing of existing stays at this location: No. Name Attach. Pt Stay angle Spread 3 7/7 7.40 45.00 . 160.00 4 7/7 7.40 45.00 »160.00 Circuit Vertical Longitudinal Transverse Resolved Ki kN® ffl® 1 .57 .00 20.21 2 .24 148.38 6.92 St. 3 9.45 -65.70 23.91 .00 13.36 la. 00 OK St. 4 9.45 -65.70 -23.91 .00 13.36 16.00 OK Total 19.70 16.98 27.13 32.00 Allowed 20.00 16.98 67.90 W/A Verdict OK OK OK OK Recoimended pole is X1KL1 For pole 11 at drainage 776.00 Pole type X1M11 Pole naae Analysis will be bottom loading Circuit Vertical Ki Longitudinal kHa transverse Hfis Resolved 1 .67 .00 42.74 2 .67 .00 35.14 Total 1.34 .00 77.89 77.89 Allowed 20.00 16.98 67.90 H/A Verdict OK OK ERROR OK Using stronger pole X1S11 Allowed 20.00 33.95 135.80 B/A Verdict OK OK OK OK Recosaended pole is X1S11 For pole 12 at drainage 886.00 TABLE (Confed«I Pole type -'<111 Pole name Analysis will be bottom loading Listing of existing stays at this location: Ho. Name Attach. Pt Stay angle Spread 5 7/7 7.40 45.00 -20.00 6 7/7 7.40 45.00 20.00 Circuit Vertical Longitudinal Transverse Resolved kH RBh tiha 1 .67 .00 23.86 2 .43 -148.38 12.69 St. 5 9.45 65.70 -23.91 .00 St. 6 9.45 65.70 23.91 .00 Total 20.00 -16.98 36.55 40.30 Allowed 20.00 16.98 67.90 H/A Verdict KARS OK OK OK Recommended pole is X1H11 For pole 13 at chainage 946.00 13.36 16.00 OK 13.36 16.00 OK Pole type X1H11 Pole name Analysis! will be bottom loading Listing of existing stays at this location: No. .Base Attach. Pt Stay angle Spread 7 7/7 9.00 45.00 “20.0-0 8 7/7 9.00 45.00 20.00 Circuit Vertical Lonaitudinal Transverse Resolved kBa kSm 1 .24 -180.13 19.44 St. 7 9.65 81.58 -29.69 .CO St. 8 9.65 81.58 29.69 .00 Total 19.53 -16.98 19.44 25.81 Allowed 20.00 16.98 67.90 B/A Verdict OK OK OK OK 13.64 16.00 OK 13.64 16.00 OK Reconsended pole is X1HH PROGRAMME COMPLETED SUCCESSFULLY.

TABLE (contd.?

Claims (5)

CLAIMS:

1. Apparatus for ground-based powerline surveying comprising means for measuring points off the route of a powerline in addition to points strictly along the route of the powerline, and means for preparing two and three dimensional representations of the line and the land surrounding it, whereby the ground profile beneath the powerline may be observed from locations referenced to, but not necessarily lying on, the actual route of the line itself, characterised in that there are provided means for measuring points a perpendicular distance from the line and means for linking the measured points together to form linear profiles at specified distances either side of the line.

2. Apparatus as claimed in Claim 1, further comprising means for the two and three dimensional determination of a reature crossing the line by measuring the point of crossing and the angle or bearing at which the feature crosses the line and, optionally, the difference in height of the feature to either side of the line.

3. Apparatus as claimed in Claim 1 or 2, including means for defining an alignment by measuring two sets of coordinates or one set of coordinates and a bearing and means for adding taped or estimated measurements to a line by reference to a previously measured point.

4. Apparatus for powerline designing comprising means for measuring points off the proposed route of a powerline in addition to points strictly along the route of the powerline, means for preparing two and three dimensional representations of the proposed powerline and the land surrounding it, means for defining the conductor design of the proposed powerline in relation to its specific environment, means for comparing and checking the conductor design parameters against industry standards and means for identifying and. specifying component requirements, characterised in that there are provided means for determining the loading on a conductor-carrying pole, means for selecting a pole suitable for bearing the determined load and, optionally, means for adding at least one stay to support the pole and determined load.

5. Apparatus for ground-based powerline surveying or powerline designing substantially as herein described with reference to Figure 1 and 2 or 3 of the accompanying drawings .