Application Integration Deployment Scenario

This section describes how a deployment of the CIM and GID can be used to create a platform for legacy application integration. This migration strategy is based on the deployment of adapters that convert legacy ways of modeling and exchanging data to CIM and GID.

Figure ‑13 Application Integration Scenario

In this case, a control center application integration project is considered. This development integrates the following applications:

· Legacy EMS

· New archive, state estimator, and power flow

· Condition-based monitoring software

· CIM-based power system modeling environment

· Data Engineering Tool

This example employed a CIM/GID-based message bus as illustrated in Figure 13.

In this example, adapters are used to connect the applications to the CIM/GID-based Message Bus. These adapters server two purposes:

· What data is exchanged

· How data is exchanged

With regard to the internal representation of data within applications or sets of tightly coupled applications, one can suggest that the value to the utility of how an application natively models or exchanges data internally is low. At the most, special analysis applications may only need to browse the lineage of data (where it came from) for auditing/validation but not details about native semantics[20]. Consequently, application integration provides a scenario where the semantics of each application may be assimilated into the common model.

With regard to how data is exchanged, IntelliGrid Architecture recommendations for application integration include the use of common model-enabled application integration technology. Specifically, instead of using a cross-industry publish/subscribe API to link applications, IntelliGrid Architecture-based application integration employs a CIM-enabled publish/subscribe API such as IEC61970 Generic Eventing and Subscription. Note that both cross-industry and common model-enabled publish/subscribe API’s are generic in that they can be applied to any application type and do not hard code application specific semantics into the API.

In essence, applications and/or systems can continue to use their internal data representation and exchange methodologies within their own domains, but are required to map to the CIM APIs whenever data exchanges involve external applications and/or systems.

This example illustrates the integration of transmission related applications using the a message bus as shown in Figure 14:

Figure ‑14 Control Center Application Integration

Figure 15, illustrates the specific GID interfaces required to integrate the applications involved:

Figure ‑15 Specific GID Interfaces Used For Application Integration

One advantage of this approach is that it facilitates incremental upgrading of the EMS and other systems, primarily within utility operations centers. In this example, a new state estimator and power flow application can be integrated with the legacy EMS using a new CIM based data-engineering tool. The data-engineering tool supplies CIM model information to the new state estimator and power flow application. The data-engineering tool also supplies a portion of the power system model to the Measurement Data Server Adapter. As discussed previously, an application uses the GID to expose information within the context of the CIM. In this case, the Measurement Data Server imports a small amount of the power model so that it can expose archive data within a CIM context.

Keeping the shared model in sync across multiple cooperating components is an important task. The GID’s Generic Data Access Model Change Events capabilities are used for this purpose. Figure 16 illustrates this process:

Figure ‑16 Data Synchronization

The steps of such a Use Case are listed below:

1. The User adds a new breaker to the EMS system’s power system model, using the EMS model server via the modeling server’s GUI.

2. The EMS GDA Server publishes a GDA Model Change Event onto the Integration Bus.

3. The Model Change Event is received by the GDA Client in the Asset Management System adapter. If there is a need to join EMS and AMS data, a mapping from logical to physical devices must be maintained. It is possible that this mapping will be done in the AMS or EMS adapter as illustrated in Figure 17.

4. The User is prompted to map new logical breaker to new or existing physical breaker in asset model using the AMS Adapter Mapping GUI

5. The archive wrapper also receives a Model Change Event.

6. In some cases, the Archive may have the ability to create a new archive point on the basis of a pre-configured template. If this is the case, then the Archive adapter can use this template and the information in the Model Change Event to determine appropriate archive configuration and add a new archive point automatically.

7. The CIM model subset in archive is also automatically updated and archiving begins. It is important to note that in order for the archive to present historical data within a TC57 namespace, only a relatively small portion of the EMS model must be maintained in the archive wrapper model manager.

Figure ‑17 Keeping the Mapping From Assets To the Power System In Sync

This workflow example can also be applied to information model changes such as the addition of a new attribute on a purchase order class. While these changes are somewhat more difficult to automate among systems, GDA Model Change Events have been design specifically to address both instance data and information model changes.

This scenario shows how applications can be connected together with adapters that can be supplied off the shelf. The deployment of TC57 based technology can lower cost significantly and thereby enable the creation of a single unified integration architecture that heretofore would be too expensive.

Again, security, network/enterprise management, and data management requirements need to be incorporated in this Use Case. Security requirements are shown in IntelliGrid Architecture Intra-Control Center Environment, and include:

· Authorization Service for Access Control

· Audit Service

· Security Policy Service

· User Profile and User Management

Network and enterprise management requirements, as also shown in IntelliGrid Architecture Intra-Control Center Environment, can rely on readily available standard technologies, such as the IETF’s Simple Network Management Protocol (SNMP) and Web-Based Enterprise Management (WBEM).

Data management requirements, although greatly enhanced by the available standards such as CIM and GDA, still need guidelines, additional tools, and automated procedures that will allow actually implementation of these concepts in the most efficacious manner.