Substation Design in the Third Dimension

Designing a substation using old-school techniques eats up labor hours like a 747 sucks up jet fuel. It is just amazing so many companies still subscribe to those same labor-intensive approaches that engineering departments were using almost 100 years ago.

Of course, some innovative utilities and engineering firms are pioneering new engineering processes, but the majority of engineering departments are designing substations manually like fine Swiss watches. Each substation is carefully crafted: a work of art, one of a kind, an anachronism. If cars were produced this way, everyone would be walking; the cars would take too long to build and be way too expensive for most people to afford.

A technological tsunami is swamping the electric utility industry today. The smart grid is everywhere. It started with meters. Then it moved to communications systems and load-management software. It was not long before focus shifted to the actual transmission and distribution grid.

Utilities added sensors, sophisticated monitoring components and diagnostics to the equipment. Computerized protection and control systems grew. Communications came in the form of fiber optics and stand-alone smart substations networked with other smart substations, forming smart grids.

Technology-Enhanced Engineering

This optimization is taking place in the engineering design process, as well. Like the hardware-oriented portion of the electric utility industry, the engineering department has a lot of smart tools in its toolbox, but they tend to be stand-alone.

Engineers have Microsoft spreadsheets and database programs. Add computer-aided design (CAD) programs like AutoCAD's Inventor, Bentley's V8i, Intergraph's SmartPlant 3D and Power Line Systems' PLS-CADD, and include analytical programs like ETAP, EMTP-RV and CYME. And the toolbox is growing. However, the system is still fragmented, disconnected and uncommunicative.

Industry-wise, utilities are stuck somewhere between the 19^th century and 21^th century technologically. Manual paper-based tasks coexist with some form of computer-assisted processes, but paper trumps technology.

Skilled designers spend their time at CAD workstations manually making detailed construction drawings (plan views, sections, a conduit plan, a foundation plan) one line at a time. When the drawings are done, highly trained engineers manually count the components (length of conduit, number of insulators, nuts and bolts) and fill out requests for purchase orders by hand. Is this the best way to use a critical resource?

Leading the Way

Although in the minority, a few organizations have evolved to the 21^st century. They are using digitally enabled technology that is connected across the enterprise, and that is the real story with designing substations in the 21^st century. Utilities such as Public Service Company of New Mexico (PNM), American Electric Power, Duke Energy, Nashville Electric Service (NES) and Progress Energy Carolinas have realized how inefficient the traditional approach was and how badly it needed optimization.

They recognize engineering-based software is capable of more. It can be linked to the business units of the enterprise. It can reduce many of the labor-intensive tasks, such as entering data automatically, and manage the project more efficiently. They also understand something has to be done to meet the expected crush of modernization required by the grid to meet customer demand for electricity.

One recent survey by SBI Energy estimated that, from 2006 to 2010, globally, utilities added approximately 11,000 new substations to their systems. SBI went on to predict that, even with the economic slowdown, roughly 8,000 more new substations will be added worldwide between 2011 and 2015. That is about 1,600 substations per year and does not include retrofitting or expanding all of the existing substations that number in the hundreds of thousands globally.

Substations in the Crosshairs

It can take a couple of engineers four to six months to design a simple distribution substation (transformer, switchgear, isolation devices and feeders). Move up in complexity to something like a transmission substation, and time consumption increases exponentially. With numbers like those, something has to be done to simplify the engineering process.

There is no reason designing a substation cannot be automated for the most part. Take a look at the typical one-line diagram. It does not take a rocket scientist to figure out they are all pretty much the same.

Of course, there will be cases that require some customization, but automated substation design typically follows the Pareto principle, more commonly known as the 80-20 rule. In other words, at least 80% of substation projects can use predefined standardized designs while only 20% or fewer will require some form of customization. That is a pretty good payback for the effort.

The solution is a standardized design. PNM developed standard designs for its substations more than 20 years ago. The utility recognized that by selecting a few basic configurations, it could streamline the engineering process.

“Once the standard configurations were defined, technicians in the CAD and GIS department customized their AutoCAD software with VLISP routines to create a series of customized menus they called 3D-DASL, now available as a plug-in for AutoCAD,” said Gathen Garcia, CAD and GIS manager of PNM.

“The designer had only to select the specific substation configuration and 3D-DASL did the rest,” Garcia explained. “The menus produce a complete set of detailed construction drawings. The best part of the process is the fact that the drawings are 3-D, only minimal training was necessary for the designer and the design/drafting process has been reduced from several months to less than eight hours.”

NES reports it has been using 3-D models for many years, too. NES is using Autodesk's Inventor software for new substations and retrofits to existing stations. NES's engineers have created a library of parts or blocks for equipment and substation components. As it developed the system, NES realized it could enhance those blocks with additional information such as embedded standards, automated calculations and material information.

Duke Energy also has been transforming its substation design process. The utility saw the need to link software, databases and processes to reduce time-consuming manual tasks into digitally enhanced efficient methods. The Duke system uses 3-D digital models of the substation created by Autodesk software using intelligent equipment blocks integrated to other business systems. Duke has automated tasks such as bills of materials (BOM) to eliminate the need to count parts and components manually for procurement.

The Industry Responds

Industry vendors such as Bentley Systems also have been working along these lines. The company's substation V8i software offers utilities some interesting 3-D substation modeling and integrated connections between MicroStation, ProjectWise and ORACLE SQL databases.

Consulting engineering companies also are adapting tools to improve their efficiency. Black & Veatch offers 3-D renderings with automated links to other business systems. POWER Engineers is developing a smart one-line diagram with embedded intelligence and links to instruction books, drawings and manuals. Mike Beehler, vice president, Burns & McDonnell, said, “Within the next five years, Burns & McDonnell expects to see all domestic substation design drawings to be in 3-D. Internationally, they see just about all design drawings utilizing 3-D capabilities.”

Beehler tells of advances Burns & McDonnell has made in the area of adding intelligence to the 3-D models. “Many of today's equipment suppliers provide detailed drawings in 3-D. These third-party drawings are imported into cells developed by Burns & McDonnell, along with steel structures, foundations, bolts, wire jumpers and everything else needed. The cells will allow for complete BOM to be generated by the software rather than have skilled designers manually count parts and components,” he reported.

Global Interest

The 3-D substation design is a worldwide phenomenon. Hydro-Québec started developing its internal 3-D CAD capabilities in 2004. The utility uses software from Dassault Systèmes to build up its 3-D substation modeling system. Hydro-Québec reports that the software allows it to join all of the various engineering groups together to produce unique 3-D models of its substations, which improves the quality of the deliverables and efficiency of the engineers.

The East China Electric Power Design Institute (ECEPDI) has made the transition from 2-D to 3-D and has designed the world's largest underground substation using Intergraph's SmartPlant 3D engineering and design software. The Shanghai Jing An 500-kV substation was designed to supply power for the Shanghai World Expo. ECEPDI has been using the SmartPlant 3D program for many years and says it increases its productivity, especially on complex projects such as this one.

Expanding 3-D

Other technologies such as light detection and ranging (LiDAR) are also finding their way into the optimization process. Terrestrial LiDAR (T&D World, August 2011) has proven to be an excellent tool for substation expansion projects. A large percentage of existing substations were built 50 years ago or more, and detailed drawings of the stations may be out of date, incomplete or, worst case, missing.

Terrestrial LiDAR scanning can provide a comprehensive survey of all the equipment, structures, foundations, bus work and lines in the substations. In a few hours, a couple of technicians can take a laser snapshot of the substation without being exposed to any dangerous clearance issues normally associated with energized substation work.

The LiDAR 3-D model can serve as a virtual substation on the engineer's computer, giving the engineer the capability of making accurate measurements and identifying clearance issues that may exist. The model also can be imported into any of the major CAD programs available today. There, they are rendered into a complete set of detailed as-built drawings for the substation in only a few weeks. And if anything was missed, the engineer can revisit it by going back to the computer and quickly crunching some additional data points. No windshield time is necessary; it is all in the LiDAR data cloud.

Game-Changing Technologies

Another area in which technology is changing substation design is surveying. GPS gives unprecedented accuracy and speed to the procedure. One utility requested a bid for the surveying of a substation expansion. A traditional surveying company included five days of expenses for a crew of three in its proposal. An engineering company using GPS surveying methods did the work in three hours with one person, and its base price was half the cost of the traditional surveying company.

Every component in the substation comes with documentation, which becomes a huge issue for storage and retrieval. Years ago, manufacturers made the switch to digital files, but the issue of retrieval across the enterprise is still a problem with utilities. Merrick & Co. has an interesting approach. It combines the 3-D LiDAR model with a panoramic visual database and links to equipment databases.

In a nutshell, anyone in the enterprise with access to a computer can view the 3-D LiDAR model. The panoramic photographs taken by the LiDAR technician at the time of the laser survey can be viewed any time. If more information is needed, the viewer can click on links to the equipment database and see outline drawings, nameplates or instruction manuals. Paper books, drawings and maps are limiting and no longer needed with the digital technologies available.

Schneider Electric has developed labor-saving smart software called System Engineering Tools, which includes a single-line analyzer function. The software is used for designing IEC 61850-based substations. These can be complex schemes with each intelligent electronic device (IED) communicating with other IEDs and the supervisory control and data acquisition (SCADA) system. The engineer scans a one-line diagram into the program, and in the simplest terms, the program recognizes the devices, assists the engineer with connections and lays out the communications system. This program replaces all the vendor tools previously required to link IEDs and SCADA, simplifying the process and removing all the iterations previously required between sessions with the separate vendor tools.

Digital Accelerators

Sophisticated software, laser scanning, 3-D digital models of substations, GPS surveying techniques, links to business management systems and databases require processing power, bandwidth and storage. Today's substation engineer can have instant access to any substation project documentation from an iPad.

A digitally enhanced optimized engineering scheme gives automated designs, which generate the bill of materials linked to the procurement system. Requests for quotes are created automatically from the BOM and purchase orders are produced from the response. Project inventory is managed from receipt to issuing to installation without data being reentered. And that is only the beginning of 21^st century technology streamlining the process. If it follows other transitions, it will only get better.