To Construct or Retrofit Transmission Lines in a Reliable, Cost-effective Manner requires accurate, consistent and detailed engineering drawings. Due to the rising demand in transmission work at Progress Energy Carolinas (PEC; Raleigh, North Carolina, U.S.), the time the utility's engineers have to design transmission systems has been shrinking consistently over the years. As a result, PEC has had to optimize its engineering design phase to boost productivity.

Standardization and automation are the two key drivers to accomplish this optimization goal. To meet this challenge, PEC's transmission operations and planning department conceptualized, formulated, validated and implemented FAST 2.0: Functional Automation & Standardization of Transmission Structure Drawings. The program streamlines the production of 230-kV and 115-kV transmission structure drawings.

Over the last few decades, PEC's service territory has been one of the fastest growing in the southeastern United States. The investor-owned utility serves 1.4 million customers in North Carolina and South Carolina in a service area of more than 34,000 sq miles (88,060 sq km).

To meet the growing demand, PEC has an impending need to plan, design, construct and retrofit power transmission lines. An effective engineering design process is a vital step toward completing projects on time and within budget. This need motivated PEC to improve and automate its engineering design processes to yield compound productivity enhancements and elevated efficiencies.

INCENTIVES FOR CHANGE

During the engineering design phase of a transmission line project, a line design tool — using the applied design criteria — generates plan and profile drawings. Based on the plan and profile drawings, engineers design and produce structure drawings using a standard computer-aided design (CAD) application. Traditionally, standard structure drawings comprise static bill-of-material (BOM) information and stand-alone graphic details on each drawing.

To facilitate timely completion of construction with no latent errors, the structure drawings must be code-compliant, accurate and consistent. Additionally, the material information contained in the drawings must concur with the parts list compiled by the BOM tool to eliminate ambiguities. Consequently, material changes that occur in the centralized material database need to be updated on several types of drawing sheets, resulting in a multi-layered data-entry process.

The conventional format of cross-referencing assemblies and parts reduces readability, potentially leading to errors in the construction of a structure. Additionally, the assembly and part designations are drawing-specific, eliminating the possibility to process the same change at one time across a group of drawings, also known as batch processing.

The conventional structure-drawing format includes all possible options for the construction of a particular structure. This format was originally intended to reduce the number of standard drawings required. However, accomplishing that goal sacrificed both the readability and the ability to edit multiple drawings at once. Combining these limitations with the need for additional process improvements provided PEC a great opportunity to simplify the otherwise laborious structure-drawing production process.

AN INNOVATIVE SOLUTION

FAST 2.0's graphic user interface is a vast improvement over the conventional method of designing project-specific structure drawings. The conventional method involves deleting the optional assemblies and parts not required for the structure construction. This process is tedious and inefficient.

To simplify and automate the drawing-production process, PEC designed and developed a graphic user interface using Visual Basic programming. A toolbar was designed within the CAD application to access any structure-family user interface. Each user interface has a set of company-standard drawings within the structure family. This setup enables a user to design a required structure-type drawing quickly.

The first page on the user interface lists important instructions for using the FAST 2.0 process, making it easy for personnel with limited experience. To initiate the design process, the user places a D-size (24-inch by 36-inch [610-mm by 914-mm]) project-specific template in the design file by clicking a button on the user interface. The project-specific template has allotted blank areas for various design elements (for example, overhead ground wire, crossarms, clamps and cross braces). The blank areas are filled in with the appropriate design elements required for that particular project using check boxes on the user interface. The user interface is programmed so that it places the correct design elements from the centralized library every time.

This process significantly reduced the production time on structure drawings without compromising accuracy, consistency or reliability. With the FAST 2.0 process, designing a project-specific structure drawing is just a few clicks away. The user interface also includes functionality such as access to the standards manual in PDF format on the company intranet.

FAST FEATURES

Material engineers modify, replace, delete and append material information in the centralized material database on a regular basis. The same changes should be included in the standard structure drawings in order to maintain concurrent BOM data. This concurrence involves a two-layered data-entry process. The goal for FAST 2.0 was to develop dynamic BOM data on the drawings that would respond to the real-time changes in the material database.

PEC devised a solution using pivot-table technology driven by an open-database-connectivity (ODBC)-compliant database. The material information in the ODBC database is linked in the form of Excel pivot tables, enabling real-time changes as they occur in the database. The dynamic pivot table replaced the static BOM text on the structure drawings. This improvement resolved the static BOM issue and eliminated the two-layered data-entry process.

ENHANCED READABILITY

The conventional structure-drawing format includes a consolidated BOM list required for construction. Assemblies, parts and bolts are listed in separate tables. This arrangement of assemblies and parts requires extensive cross-referencing, leading to a poor readability format. To enhance readability, PEC has segmented the material into assemblies required to construct each corresponding design detail.

For instance, an overhead ground wire detail has only the material table required for overhead ground wire configuration. The new design incorporates the material list above the vector graphical elements in every design detail, enabling quick navigation to identify the material specifications.

The application of pivot tables improved this process. The Excel pivot tables were linked within the CAD cell using an object linking and embedding technique. Using pivot tables in the engineering design process is an innovative way to integrate assemblies and parts for enhanced readability, as well as to facilitate easy maintenance.

With the conventional practice, the item number identifying each part is specific to each drawing, eliminating the possibility to process changes in batches when a change is required across a group of drawings. To remedy this situation, PEC assigned a unique item number for each part in the database, facilitating batch processing. A bracket identified by a specific item number is the same across all drawings, thus providing and enforcing consistency, and facilitating the batch-change process.

OVERWHELMING BENEFITS

A project-specific structure drawing is estimated to take 10 hours using the conventional process; it would take approximately 10 minutes using the FAST 2.0 process. That's a 97.5% time savings realized using the FAST 2.0 process versus the conventional process.

With the FAST 2.0 process, engineers can consistently produce accurate and easy-to-read drawings, all to the benefit of the organization. The cost-benefit implications are enormous. If the engineer's loaded cost is assumed as US$55 per hour, the generation of a single drawing using the conventional process represents $550. By comparison, the FAST 2.0 process represents a cost of less than $10. And, if one assumes 40 projects a year and an average of five structure drawings per project, those numbers get multiplied by 200 to represent annual costs.

The FAST 2.0 tool is highly efficient compared to the conventional process. Users generate the desired output with limited resources and minimal effort. The efficiency relies on reducing redundant tasks. PEC addressed the redundancy factor effectively to gain efficiency in several areas, including time, money, accuracy, consistency, reliability and maintenance. The efficiency gained in terms of time and money is more than 95% in both areas.

ACKNOWLEDGEMENTS

The authors extend a special thanks to Mick Vander Ploeg, director of project management at Progress Energy Carolinas, and Rhonda Webb, a manager for the utility, for envisioning and laying the platform for a design-automation strategy in the transmission department. Thanks also goes to Paul Cox, a lead engineer in line engineering, Ray Watkins, senior engineer, and Leo Gladney, manager of line engineering, for their unparalleled and continuous support, which resulted in this project success and fruition.

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Shiva Korremla (shiva.korremla@pgnmail.com) is a promising engineer at Progress Energy. His critical thinking and application of advanced concepts realized improvements in areas unexplored by the utility industry. His job responsibilities include automating and improving transmission engineering design processes with the aid of 3-D parametric modeling, Visual Basic programming, database concepts and Kaizen techniques (subset of the Lean system). He received a MSME degree from the University of Texas at El Paso.

David Dudley (david.dudley@pgnmail.com) is a seasoned line designer in the transmission operations and planning department at Progress Energy. His cross-functional expertise enabled the developers of FAST 2.0 to capture all possible scenarios, to prevent any potential issues. His job responsibilities include siting, permitting and designing transmission lines as well as training engineers new to the group.

Michael Goins (michael.goins@pgnmail.com) is a valued team member in Progress Energy's design automation projects. His role is to act as a liaison for the design automation team and technology group to accelerate the database re-engineering process required for the FAST 2.0 project. His job responsibilities also include CAD application support and training. He received a bachelor's degree in computer information systems and is pursuing an MBA degree.

Mike Kirkland (mike.kirkland@pgnmail.com) is manager of the transmission technical specifications and standards unit at Progress Energy. He fostered the design automation strategy, foreseeing the potential benefits to engineering units and the organization as a whole. His role is to monitor and control the design automation projects by providing the required resources. He holds a BSEE degree.

Summary of Time and Cost

Task	Time		Cost
	Conventional process	FAST 2.0 process	Conventional process	FAST 2.0 process
One drawing	10 hours	10 minutes	$550	$9.16
Yearly (200 drawings)	2000 hours	33.3 hours	$110,000	$1832