The first two elements of PJM Interconnection's mission statement are to maintain the safety, adequacy, reliability and security of the power system, and to create and operate a robust, competitive and nondiscriminatory electric power market. As PJM (Norristown, Pennsylvania, U.S.) implements its mission statement through the Regional Transmission Expansion Plan (RTEP), it becomes critical to take advantage of beneficial decision support tools, such as a geographic information system (GIS), to optimize and streamline current and planned business enterprise practices.
By integrating business enterprise information with system mapping data, PJM's Transmission and Interconnection Planning Department leverages existing mission critical information while simultaneously creating a new, spatially dynamic visualization and decision support tool. A GIS will enable Transmission and Interconnection Planning to evaluate the RTEP and related information more efficiently.
Electric Industry Application of a GIS
The location of PJM's infrastructure can be mapped in a GIS. However, a GIS takes mapping to a more sophisticated, usable and reusable level. This distinguishes GIS from other design and drawing software due to its unique ability to study interrelationships and support complex analysis using powerful tools which link a series of map layers to associated information about those layers. For example, substations, generators, circuit breakers, transformers and transmission lines all have associated attributes such as voltage ratings, type and circuit identification. In the GIS, each element of the system is intrinsically related to service cost, project scheduling and facility information. The GIS bridges the gap between spreadsheets, facility locations, cost allocation, planning and business modeling tools. This bridge enables decision makers to consider alternatives more quickly and effectively. As a formal data resource, a GIS makes information that was previously scattered among many sources readily identifiable and easily accessible to users of all skill levels.
Why Use a Geographic Information System?
The System Planning GIS (SPGIS) is a powerful tool that allows PJM to visualize geographic relationships between facilities distributed over its vast system. For example, PJM has studied 501 generation interconnection requests totaling more than 137,000 MW in 14 different queues. Decisions made in Queue A can have significant impacts on later queues such as Queues B or C. Planners using the GIS will have the immediate benefit of analyzing dynamic project schedules and costs associated with transmission system upgrades. As PJM's charter expands as an RTO, better visibility of larger amounts of data with geographic relevance is necessary.
Phased Implementation Plan
Phase 0: GIS Pilot Project
A GIS pilot project was developed and served as the beginning of a broader GIS implementation life cycle. The GIS pilot has enabled Transmission and Interconnection Planning to continue with its plan for GIS development and implementation with a well-defined plan of action for GIS integration with the market growth activities.
Phase 1: System Planning GIS (current phase)
To meet the system planning geographic application needs, several important GIS databases had to be developed. Development of these key databases includes:
- Generator facilities milestones
- Individual generator milestones
- Attachment facilities milestones
- Network upgrades
- Baseline upgrades
- Organizational boundaries
- Political boundaries
- Existing facilities
- Planned facilities
- Transportation layers (interstate and arterial level)
- Environmentally sensitive areas.
As PJM's facilities information and GIS application inventory is developed, access to decision support programs is further enhanced. The end users will query and retrieve data through decision support systems for visualization and analysis. The system will facilitate the department's tasks involving system development over a large geographic area encompassing PJM's member companies.
Phase 2: PJM GIS Enhancements
In this phase, corporate standards for databases are achieved, and the focus is on the development of a corporate-wide spatial inventory to support multiple departments. Significant benefits could be realized in an effective implementation that supports PJM's power market and system operations. For example, voltage profile information was integrated with the GIS to create a 3D surface depicting voltage variances across the system (Fig. 1).
GIS Implementation Approach
As stated previously, implementing a GIS is accomplished through incremental phases. These phases lead to the generation of databases and applications to support priority needs with built-in flexibility. Each phase can be characterized as an evolution through a series of four typical stages (see sidebar). The GIS life-cycle stages are shown in Fig. 2.
The GIS functionality will develop from proof of concept through System Planning support to help manage Interconnection Planning work. The next phase will be to incorporate other PJM core business to support system operations and markets.
PJM's Current Use of GIS
The SPGIS is composed of three scales of information: transmission, cluster and subcluster. The three scales are topologically connected into a single fabric of information encompassing all layers of data, and geodatabase relationships and rules govern other interdependent behaviors.
Transmission Scale geospatial information is composed of features such as transmission lines, substations and queues (generation projects in a queue for study). These features are considered the backbone of the overall SPGIS. As shown in Fig. 3, the transmission scale represents the smallest scale of information, covering the whole geographic extent of PJM's planning area.
Features at the transmission scale are related to the overall System Planning Database Structure (SQL server) through a combination of ID fields. This enables engineers within the Transmission and Interconnection Planning Department to query any pertinent information within the System Planning Database using the GIS as the window into all system planning information.
Cluster Scale has a more detailed, larger-scaled set of features. The features that comprise this scale are: substation footprint, components (breakers, transformers and generators), busses and interconnection lines. The cluster scale is characterized by features that are georeferenced. The cluster scale features are connected to the transmission scale lines, and rules have been established for their relationship to other cluster scale features (Fig. 4), as well as to the transmission scale. The features within the geodatabase at this scale are related to the appropriate database tables within the System Planning Database through the use of individual component IDs or a combination of IDs.
Subcluster Scale is composed of the same features as the cluster scale, but the primary difference between the two is in how the information is viewed. While ArcMap is the primary viewing and editing tool for the transmission and cluster scale geospatial information, ArcSchematics is the viewing and analytical application for the subcluster scale (Fig. 5).
Transmission and Cluster Functions. Instead of studying multiple spreadsheets and computer-generated drawings independently, the Transmission and Interconnection Planning Department has developed a database system to meet its operation and planning needs. The SPGIS must relate to this database in a meaningful way, and appropriate information must be integrated with the GIS at the three scales of analysis and visualization. For example, upgrades to the current transmission system can be visualized in a variety of ways, such as viewing the impact(s) of a new generation project on the bulk transmission system (Fig. 6).
Another example involves the status of generation projects. A query of the System Planning Database is integrated with the GIS to visualize generation project status, as well as queued generators that are in-service operating at more than 100 MW.
Numerous documents, from engineering to legal, are associated with each queued project in the transmission system. The transmission scale feature datasets provide an opportunity to manage and retrieve any kind of document related to a particular queue or substation (Fig. 7).
Drilling down into the cluster scale features in the geodatabase allows PJM engineers to visualize a more-detailed dataset, such as individual bus configurations, circuit breakers and transformers. All components (circuit breakers and transformers) are maintained in the geodatabase and have representation in the System Planning Database. Features such as construction status and dates can be viewed as well.
The geodatabase allows PJM engineers to analyze and visualize system planning data in ways only limited by the imagination. For example, Fig. 8 shows in-service megawatts by state in the PJM system. A query was performed to total the in-service megawatts by state, and then the state polygons were extruded from the surface based on the number of megawatts in-service in that corresponding state. The states were then annotated accordingly, as shown in Fig. 8.
Data Visualization Applications
The Transmission and Interconnection Planning Department at PJM currently uses a database through an intranet portal. This information can be queried and analyzed to create visual models. The GIS application is used for creating additional data sets, developing new data relationships, reporting and editing information (Fig. 9).
Future Direction of System Planning GIS
The Transmission and Interconnection Planning Department has taken a proactive stance as it anticipates extensive growth in the near future. The GIS is being constructed in a manner foreseeing PJM's long-term objectives and serves as the kernel around which the PJM enterprise-wide GIS can be built. Although the initial focus is to facilitate the specific goals and objectives of the Transmission and Interconnection Planning Department, an even greater advantage can be realized through a SPGIS and ultimately a company-wide application of a GIS. This system would allow PJM to visualize and analyze information from multiple databases in an innovative and collaborative manner that is beneficial to all stakeholders. In conclusion, this unique application offers a versatile platform to visualize dynamic infrastructure data of the bulk power electrical grid on a regional basis as never done before.
Kenneth S. Seiler is manager of Interconnection Planning at PJM Interconnection, responsible for the interconnection coordination of generation, substation and transmission projects. Over the past three years, he has been extensively involved in the development of PJM's data visualization efforts related to the regional transmission expansion planning process. Prior to working for PJM, he worked at GPU Energy for 13 years in electrical equipment construction and maintenance and relay protection and control departments. Seiler received a BSEE degree from the Pennsylvania State University and a MBA degree from Lebanon Valley College.
Patrick Moore is director of Integral GIS, a geospatial application development and integration company based in Seattle, Washington. Prior to Integral GIS, Moore worked as a software engineer for the Microsoft Corp. He holds bachelors degrees in mathematics, physics and computer science, as well as a masters degree in environmental engineering, all from the University of Washington.
The Evolution of GIS Implementation
Stage 1: Education, Understanding, Acceptance and Support
- Rapid map generation
- Map query and reporting systems
- Small short-term spatial analysis projects
- Technology awareness by decision makers
- Focused applications for business needs
Stage 2: Geographic Data Catalog/Inventory
dentification of shared data requirements
Systematic development of long-term and reusable spatial databases
Integration of core tabular databases with spatial databases
Integration of corporate databases
Creation of database maintenance programs
Testing business-case hypotheses
Stage 3: Analysis, Data Queries and Retrievals
Custom spatial-analysis projects
Identification and development of reusable custom GIS analytic applications
Creation of geodatabase models
Further proof of the business case
Stage 4: Decision Support Tools
- Development of “plug-n-play” spatial support tools
- Development and distribution of packaged solutions
- Taking advantage of business-case benefits
- Possible intranet-based applications