## 2 CIM-Based DMS Platform Structure Considering Interoperability  
### IEC TC57 Cim  
The IEC TC57 CIM standard originated from EPRI's control center API (CCAPI) research project [28]. Initially, the project aimed to streamline the process and cost of integrating new applications into EMSs or other systems while also minimizing investments in existing, well-functioning applications. It sought to provide an integrated framework for connecting existing applications and systems. The main objective of the IEC 61970 series is to integrate applications developed by multiple suppliers within a control center environment. It provides a comprehensive set of guidelines and standards to facilitate seamless information exchange with external systems of the control center. The IEC 61970 standard is structured based on the CBD methodology, which involves developing and combining independent components separately to construct a software system. By utilizing the CBD approach, applications can be integrated by modifying the component container, even changes in the communication layer.  
The IEC 61970 standard defines the base CIM as the standard information model, which is crucial for ensuring interoperability among components within EMS [7]. CIM is an abstract model representing the various power system resources using object-oriented modeling techniques. In this study, the latest version of the CIM UML model officially released by the CIM User Group was adopted. The applied version, CIM UML 100.1.1.1,incorporates IEC 61970 version 17.40, IEC 61968 version 13.13b, and IEC 62325 version 3.17b. Released on 4 July 2022, this version supports the integrated application of the three CIM standards. To provide a clearer overview of the scope and purpose of these standards, Table 2 summarizes the key features and application fields of the IEC 61970, IEC 61968, and IEC 62325 standards.  
It enables the modeling of logical information, such as equipment or voltage/current required for actual power system operations, into recognizable object forms. These objects are represented by classes and attributes, organized into logical packages, each corresponding to a specific part of the entire power system. A subset of the complete CIM is referred to as a profile that contains only the corresponding information for a specific data exchange. Figure 1 shows the Unified Modeling Language (UML) diagram of the profile representing network topology. It includes classes such as ConductingEquipment, Terminal, and ConnectivityNode. ConductingEquipment models equipment that is responsible for conducting electricity and serves as a top-class entity encompassing various power system components such as ACLineSegment, Switch, and EnergyConsumer. Terminal represents the physical junction that connects multiple ConductingEquipments, while ConnectivityNode serves as a node facilitating connections between ConductingEquipments. Each ConductingEquipment is connected through Terminals. Figure 2 shows how to represent a simple distribution network in CIM. It depicts a structure that connects Terminals at both ends of ConductingEquipment and connects Terminals to ConnectivityNodes. If the connections in the real system of Switch1, Branch7, and Load5 are expressed by CIM, then Switch1, Branch7, and Load5 correspond to Switch1, ACLineSegment7, and EnergyConsumer5, respectively. The interconnection of Switch1, ACLineSegment7, and EnergyConsumer5 can be expressed by ConnectivityNode3 connecting Terminal2 for Switch2, Terminal6 for ACLinesegment7, and Terminal4 for EnergyConsumer5.  
Figure 1: UML diagram for a profile regarding network topology.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
\begin{tabular}{c} Supports data exchange between distribution management \\ systems (DMS) and other utility applications. \\ Provides models and messages for electricity market \\ communications based on CIM. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 2: Overview of CIM-Based Standards.