Part 2: Cleaning up your Grid Network Model Management “Junk Drawer”

Part 2: Grid Network Model Management (GNMM) Features

and the Grid Network Model Management (GNMM) Ecosystem

In part one, we discussed the “junk drawer” metaphor for the grid model management situation that most utilities find themselves in.

First, let's refresh our view of the Network Model Management System (NMMS) ecosystem. This view is reflected in the simplified diagram below.

Figure  Simplified Network Model Management System (NMMS) Ecosystem

These systems should be the system of record (SoR) for the data with which they are charged. Consider some of these examples:

• SCADA for grid state
• Work and Asset Management – Assets and the Work records associated with assets.
• AMI – metering data
• CIS – customer data
• OMS – outage data
• GIS – equipment, locational data
• NMMS - Network model management system that can pull these various inputs together to give utilities insight into, and confidence in, the data related to the state of the network.

The importance of this ecosystem is reflected when one considers the entire asset management lifecycle. This simplified version of that lifecycle is shown in the figure below.

Figure  Simplified asset lifecycle

Features of the GNMM solution

As stated earlier, the NMMS provides a single trusted source of accurate and up-to-date grid network data. The data is easily accessible to all authorized users, and relevant systems (from planning to operations) and use the same “single version of the truth” source data that has been validated through data quality and network connectivity processes.

Network model exchange is automated, and changes in participating systems are consumed by NMMS to update the model with As-Built and planned networks. Subscribing system data transformation is built into the NMMS solution, eliminating the need for manual data exchange manipulation. The system provides a single switch-node model that is automatically reduced to a bus-branch model for relevant subscribing applications, eliminating the need to maintain a separate bus-branch model.

The NMMS also provides a 360-degree view of As-Built, Planned, and As-Designed networks with relevant point-in-time views and future timelines. It combines data from various systems to host the entire network model in a single system. The NMMS hosts various views of the network, including the historical network, current as-built network, and future as-planned networks. It also provides the ability to associate different operating conditions to the selected network model, such as switching states (as-designed vs. as-operated), and electric loading, and environmental conditions.

Support for the full Asset Lifecycle from planning to design, construction, commissioning, operation and maintenance, and eventual retirement. This will allow, amongst others, for capturing the data once and re-using, and for the as-built network data to be ready for network operations in time for energization.

Assimilate data from various sources, including equipment and all the electric properties, network topology (connectivity), measurements and related SCADA points, service points, equivalent sources, electric loads and load profiles, calculated impedance values, equipment configuration settings, relay settings, equipment ratings and branch or circuit limits.

Perform data and grid network validation as part of a quality assurance process before publishing to subscribing applications. The GNMM solution would utilize features such as rule validation, load flow simulation, topology processing, one-line diagram auto-generation for manual validation, and state estimation validation^[1]. Identification of data and network connectivity errors will be referred to the source systems for fixing before publishing to end consumers.

Manage electric loads and load profiles are part of the network model are used for network planning as well as load flow, model validation and other studies. Loads could either be measured or calculated. Manage and possibly calculate Thevenin Equivalent Sources.

Manage measurement objects which arelinked to Equipment objects and associated with the relevant SCADA Points

Manage, transform, and publish network models in target proprietary formats such as PSS/E, Synergi, CYME from a single, common vendor-neutral format, which includes transformation from switch-node to bus-branch transformation and vice versa. Tracking of network model versions and provenance (auditing and tracing of transactions) and support for various statuses such as Current (As-Built), Future (Planned and Designed Projects), and Past (Historic) network models, including the switch open/closed states

Manage schematic one-line diagrams, supporting functionality for auto-generating (from underlying connectivity + annotations), diagram versioning, publishing either as operating diagrams, or as SCADA/EMS/ADMS diagrams that can be imported.

Best Practices and Key Requirements for a Grid Model Management Solution (GNMM)

Before we go much further, it is important to reflect on the key GNMM requirements and best practice guidelines. These include:

1. Streamlined Operations: GNMM aims to eliminate redundant tools and datasets, ensuring a well-architected solution without accidental complexities, inconsistent data, or lack of access control. Align processes and systems across the asset lifecycle value chain to work as a system of systems, rather than being focused only on its immediate KPIs.
2. DER Integration Support: GNMM is foundational for integrating Distributed Energy Resources effectively into the electrical grid, allowing optimal assessment, planning, design, and operation.
3. Network Planning Excellence: GNMM enables the management of current and future network states, linking with load forecast datasets, asset catalogs, and protection settings for comprehensive network planning.
4. Open Standards-Based Network Model: Adherence to the UCA/CIMUG CIM data model and IEC TC57 standards ensures avoidance of vendor lock-in and supports standardized grid model exchange. GNMM should adopt a fine-grained Node-Link representation based on these open industry standards.
5. Logical Separation of Equipment and Asset Data: GNMM supports the logical separation of equipment and asset data, easing the implementation of the utility-connected asset lifecycle.
6. Proprietary Grid Model Format Support: Automated transformations to and from proprietary grid model formats ensure usability across applications while maintaining a single version of the truth.
7. Single Equipment Type Catalog: A centrally maintained equipment type catalog ensures consistency, avoiding the need for separate libraries for each application subscribing to the GNMM model.
8. Link to Load Repository: GNMM manages a single source for 'Load’ and ‘Derived Load’ data such as load profiles, linked to grid network model load objects and published to all consuming applications.
9. Network Schematic Diagrams: GNMM automates the generation of network schematic and operating diagrams for centralized maintenance and publication to systems like ADMS and EMS.
10. Equipment Ratings and De-ratings Management: Determining operational limits and capabilities for accurate network analyses and simulation, such as load flow studies and contingency assessments.
11. Limits and Limit Sets Management: Using equipment ratings and protection settings to manage constraints for components, preventing overloads or potential failures. Capturing details related to protection settings also supports the analysis of network resilience to faults.
12. Equipment Installation Settings: Detailed information on installation configurations and settings for equipment such as DER and reclosers for accurate representation of real-world installation scenarios.
13. Project and Model Part Management: Supporting segmentation and organization of the network model, facilitating efficient handling and focused analyses, such as transmission, sub-transmission, and distribution.
14. Data Integration from Various Sources: Managing data integration from diverse sources to ensure timely availability of accurate as-built network data.
15. Network Validation: Integral to quality assurance, network validation applies defined criteria and conducts analyses such as load flow simulations and Single Line Diagram (SLD) generation for manual validation.
16. Network Model Version Management: GNMM implements a systematic approach to tracking model versions, enabling parallel developments, validation, and seamless incorporation of changes while preserving data integrity.
17. Manage Thevenin Equivalent Sources and Loads: Calculating and managing Thevenin Equivalent Loads and Sources for accurate simulation and analysis, supporting network segmentation.
18. Equipment (TypeAsset) Catalog: A single equipment catalog reduces the effort required to maintain a separate equipment catalog for each application, which would result in a divergence of data and reduced data quality.
19. Measurement Management: Manage the link between ‘Measurement’ objects which are linked to ‘Equipment’ objects and the relevant SCADA Points so that other applications and analytic solutions can utilize SCADA time series data efficiently.

What’s Coming Next

Stay tuned for part three, where we discuss ‘charting the path for grid model management success.

Invitation: Join us at DistribuTECH 2023 for a more in-depth Utility University course: Improving Data Quality with Network Model Management.