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Abstract

Content

Introduction

Development projects for the creation and reorganization of the high-voltage overhead lines power associated with many difficulties. Even with the large number of existing software, these products have a number of shortcomings.

According to National Electrical Code of Ukraine, the degree of wear on the transmission grid is now more than 40%. This finding suggests that in the near future will begin active reconstruction of worn units of electrical systems, and their replacement by newer ones. Therefore, to simplify the process and to speed it up, you need software that can fully meet the requirements of the designers.

The opportunity to automate the design process can do with use of modern technology. Developed programs to automate these processes are referred to as CAD (CAD). CAD techniques are aimed at improving the design, namely:

1. Theme urgency

Since the design of overhead time-consuming task that often are utilized several departments of the design organization. That's why automation design of overhead lines must embrace the entire process chain. Efficient automated design of overhead lines is a very urgent problem of our time. Automation provides a rational allocation of functions between humans and computers: the designer solves the problems of a creative nature, and PC – formalized tasks that are implemented in the form of an algorithm.

CAD is implemented as a set of applications that provide design, drawings, modeling of structures. Today more and more organizations to solve design problems trying to use the CAD is caused not only by the desire to keep up with technological progress, but also a desire to simplify the work of the designer, improve productivity and quality of the projects. The introduction of CAD design institutes and organizations can accelerate the process of project implementation and significantly reduce the impact of human factors [ 1 ].

At the moment, the department of electrical systems of Donetsk National Technical University, there is software for CAD of high-voltage overhead power lines (Figure 1), but to meet the full requirements of the design organizations, it needs to be rework and improved. While working with the software package have been identified inaccuracies present the results of calculation errors in the program, as well as some of the errors related to the mathematical calculations that are within the master's work is planned to eliminate.

Program of mechanical calculation of overhead lines

Figure 1 – Program of mechanical calculation of overhead lines
(animation: 21 frames, 5 cycles of repeating, 108 kilobytes)

Therefore master's work is devoted to the actual topic. The developed software can be used for training purposes, as well as in the departments of design, to speed up the delivery of finished projects related to the structure or reconstruction of existing overhead power line.

2. Goal and tasks of the research

The purpose of the master's work is the development of software for automatic design of overhead power lines with a tool CAD - AutoCAD.

Objectives of the master's work:

  1. Review and critical analysis of existing software, teaching and research of the linear subsystem of a CAD overhead lines of 35-750 kV.
  2. Optimization of existing algorithms of teaching and research CAD overhead lines, taking into account the requirements of the current of Ukraine Electrical Code.
  3. Development of the module teaching and research of the automatic design of overhead lines for the placement of the supports using CAD-technologies.
  4. Development of the module teaching and research of the automatic design of overhead lines for the calculation of transition using a CAD-technologies.

3. Review of existing software

Teaching and research CAD overhead lines, currently in use in the department of electrical systems of Donetsk National Technical University, realized on the algorithms developed in the 2010 Master Lena Allagulova [2].

To optimize your code CAD overhead was created an information database containing the information needed to calculate the mechanical strength of the wires. Use a relational tabular data model. The local database is stored in one file, which entered into several tables. Was used DBMS – Microsoft Access.

The very same software was developed Khvorostianenko Mykhailo [1] with the object-oriented programming language ‐ Delphi 7. In general, the linear subsystem is stable, but when you work with it, have been identified inaccuracies and errors of calculations that are to be addressed within the master's work.

At this point, the application of complex software systems design automation, debugged and optimized only program of mechanical calculation of overhead power lines of high and very high voltage. It partially implemented algorithm sag in CAD AutoCAD.

4. Working with CAD

One of the most common CAD systems used by engineers from various industries, is AutoCAD. The advantage of using CAD is manifested in higher productivity from the engineers. In contrast to the drawings, which are performed in common graphic file or manually, engineers can make projects CAD much faster and higher throughput means that the number of workers can be reduced. This leads to a decrease in personnel costs, and the final product produced using CAD technology, is of higher quality and competitiveness.

The modern system of AutoCAD as a standard programming tools support LISP, ObjectARX, and Microsoft Visual Basic for Applications (VBA). At the same time, a lot of engineers who are not professional programmers have mastered the development of applications in Borland Delphi. Many of them are working simultaneously with AutoCAD.

The company Autodesk does not officially support Delphi as a standard for application development, but the introduction of a system of AutoCAD ActiveX technology makes it available for programs created in environments that use COM technology. However, there are non-standard techniques to operate the system from any AutoCAD programs. It should be noted that the use of any tools require a developer knowledge of the language LISP, but it is quite a powerful tool that allows you to perform all the necessary functions. Do not attempt to use Delphi to complete the development of large-intensive applications with a graphical base AutoCAD. Such programs are, of course, need to be developed using ObjeclARX or LISP.

As an example, in the use of AutoCAD CAD a procedure developed by Khvorostianenko Mykhailo:

procedure TForm1.Button1Click(Sender: TObject);
var
BeginPoint, EndPoint: OleVariant;
Line: IAcadLine;
Begin
// set the variable type of the array of three real numbers
BeginPoint:= VarArrayCreate([0, 2], varDouble);
EndPoint:= VarArrayCreate([0, 2], varDouble);
Try
// end point is given by the calculus of origin through the increment,
// specified in the original Excel file
EndPoint[0]:= BeginPoint[0]+PrX; // coordinate X
EndPoint[1]:= BeginPoint[1]+ PrY; // coordinate Y
EndPoint[2]:= BeginPoint[2]+ PrZ; // coordinate Z
// function returns an AddLine IAcadLine built site,
// wich we assign the corresponding variable
Line:= AcadDoc.ModelSpace.AddLine(BeginPoint, EndPoint);
// now with this line you can do whatever you can AutoCad, for example
// change the color
Line.color:= acRed;
// change the line thickness
Line.Lineweight:= acLnWt040
except
end;
end;


The interaction of the program calculate the mechanical strength of the resulting graph is overhead in the environment of AutoCad (figure 2).

Example applications AutoCad to display the results of calculations of mechanical wire

Figure 2 – Example applications AutoCad to display the results of calculations of mechanical wire

Next, there is the possibility of further formatting of the results, printing, saving on storage media.

Conclusion

The result of the qualifying master's work is the creation of teaching and research CAD of overhead lines that will fully perform the calculations required for the design and reconstruction of the overhead lines, with the construction of illustrative drawings in AutoCAD.

While writing the current author's abstract the master’s work is not finished yet. The final completion will be by the 1st December 2013. You may obtain the full work’s text and all the materials from the author or his supervisor after the stated date.

References

  1. Khvorostianenko Mykhailo — "Working out and research of the software of a subsystem concerning a linear part of UD CAD of air ETL 35-750 kV.".
  2. Lena Allagulova — "Improvement of information and mathematical software TR system CAD overhead transmission lines 35-750kV".
  3. Model Studio CS ËÝÏ v.2 [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: http://www.csoft.ru/....
  4. EnergyCS Line 3 [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: http://www.csoft.ru/....
  5. Ïðîåêòèðîâàíèå ËÝÏ [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: http://xn--c1adxddabidmmx3i.xn--p1ai/....
  6. Power Line Systems [Ýëåêòðîííûé ðåñóðñ]. – Ðåæèì äîñòóïà: http://www.powline.com/products.html.
  7. Ïðàâèëà óëàøòóâàííÿ åëåêòðîóñòàíîâîê. Ãëàâà 2.4, ãëàâà 2.5 ³ç çì³íîþ ¹1. – Ê.: ÃвÔÐÅ, 2006. – 143.