Power Technology Issue 100

SIEMENS Power Transmission and Distribution

Power System Visualization with Google Earth™ Dr. Neeta Patwardhan Senior Software Engineer neeta.patwardhan@siemens.com

Google Earth™ is a powerful tool that combines Google’s search feature with a rich variety of visual information - high resolution satellite imagery, maps, terrain data, multimedia content and life-like models of buildings. Google Earth™ is readily available

and can be easily downloaded from (www.google.com) and provides an easy interface for 3D viewing and sharing of geographic information. Additionally the Google Earth community with millions of users around the world is a valuable and free resource for gathering and sharing ideas.

By incorporating Google Earth™ technology into Siemens PTI’s product suite, we bring to your desktop a wealth of possibilities - view graphical one-line diagrams against the backdrop of virtually any location, add tailored 3D models of power plants, view the area spanned by an outage, fly over an entire network or zoom in to a particular transmission tower. Using this new feature engineers can explore by visualizing location specific data related to power systems as well as create powerful presentations.

One-line diagrams with geographic coordinate information can now be exported to KML (Keyhole Markup Language) format from Siemens PTI’s diagram management tool. Google Earth understands KML and requires location information in the form of Latitude and Longitude. These coordinates should be in WGS-84 (World Geodetic System). Various tools are available to import geographic data e.g. PSS™E users can import geographic coordinates with the help of a bus location file. Users can thus view network diagrams superimposed on any location of interest around the globe. This innovative feature has recently been enabled in various products across our suite, and can be an important visual aid in research and analysis.

We provide a template based architecture that maps component names on diagrams to templates. An easily extensible set of KML templates is included. These are expanded and used for rendering selected graphical elements in Google Earth™. The generated KML can be adapted to customize representations for symbols. Snippets of KML code from the virtual community can be combined with our templates to achieve any desired special effects. By modifying existing templates, features can be rendered in a particular style. E.g. branches displayed as very thick green lines or buses represented with company specific images. Hence, network display attributes can be modified according to user specifications. Furthermore, new templates can be added or existing ones completely replaced making for a highly configurable and flexible design. By providing modifiable templates, our export feature de-couples the KML code that Google Earth understands, from our graphics.

In addition, it is possible to bulk select or deselect components to be published from the diagram. Alternately, a user can turn off a few specific elements that need not be exported. A graphical element in a network can be represented in Google Earth as a user defined drawing, an icon, an image or a textured 3D model. Siemens PTI provides a library of these that can be modified. Customized models, icons and images can be added to our existing set. New 3D models can be created or edited with Google Sketchup – a free drawing tool that simplifies 3D design and lets you place your models in Google Earth. Moreover Google 3D Warehouse provides a rich resource to share, search for and download models.

Users may also make adjustments to the level of detail required by editing templates. E.g. within a certain range, icons are seen but when zoomed in further a complete 3D model of the feature is visible. Annotation can be associated with components on a diagram. This will appear as comments in a placemark, visible only when the mouse is over the specified location making it a useful presentation and collaboration tool.

Power Technology August 2007

Page 2

The export function has thus been designed to provide a complete framework that can be used out of the box or expanded to meet specific needs. Viewing networks in Google Earth enables clients to exploit free, state of the art technology with a single export. By combining the power of an atlas, a flight simulator and a powerful search engine, visualizing power networks with geographic data is limited only by an engineer’s imagination. The only downside – too much fun can be addictive!

Figure 1 - PSS™E Generated Overview of a Partial Network Located around Albany, NY

Power Technology August 2007

Page 3

Figure 2 - PSS™E Generated 3D Model of a Power Station Zoomed in View.

Figure 3 - PSS™E Generated 3D Model of a Transmission Tower Zoomed in View