Development of a Portable SCADA System for Substations complying with International Standards and Logical Node Assignment Organization

Control and Data Acquisition, SCADA) for substations that aims to reduce costs while preserving operational capability under practical field operating constraints. The system connects to the substation’s internal network only when needed. Communication paths are redundant to tolerate failures and maintain continuity during equipment or link issues. A converter translates between the IEC 61850 international standard and the company’s proprietary legacy protocol, and it aggregates data from intelligent devices so operators can handle all device data in a centralized and consistent way. Software running on a commercial laptop provides safe operation, including a confirmation step before issuing commands, immediate display of status and measurements, clear color indications when data become unreliable due to communication loss or abnormal status, event and history logging to ensure traceability, time synchronization to maintain consistent timestamps, prevention of unauthorized connections by whitelisting device addresses, and antivirus and application control protection that allows only preapproved programs to run. In our evaluations, delays in status and measurement displays met the target values. Some control operations slightly exceeded the targets due to device-side processing time, but this was judged acceptable for practical field operations. In parallel with the technical development, we addressed the operational burden caused by fragmented, person-dependent knowledge in daily work. Differences in device configurations and settings across substations tend to necessitate site-specific data mappings, customized screens, and tailored control logic, which increases dependence on individual staff and slows onboarding and handovers. If the use of IEC 61850 logical nodes—an approach that groups data by function—is inconsistent, design and test teams may interpret the same data differently, resulting in mistakes and rework. When standards or device models are updated, such ad hoc practices quickly become fragile, increasing both update costs and the risk of configuration errors. To mitigate these issues, we took three concrete steps. First, we defined common, siteindependent data management requirements that scale to the largest anticipated device configurations, reducing the need for special handling at each site and aligning engineering and maintenance work. Second, we established basic rules for selecting and assigning logical nodes and shared them in tabular form so that data are placed consistently across devices, which helps prevent design drift (inconsistencies that accumulate over time) and clarifies expectations for both users and vendors. Third, drawing on diverse use cases such as equipment failures, we compiled manuals that systematically describe how events occur, how they appear on screens, and recommended response steps. This enables faster and more consistent troubleshooting in the field and in control rooms. These materials are maintained with version control and recorded change histories, and their content is being enhanced step by step through practical use. As a result, we are building a foundation to reduce personnel dependence, shorten training and handover times, and achieve uniform quality across sites. The portable SCADA also helps reduce the number of permanently installed terminals, offering a practical solution that can be deployed with limited resources while supporting reliable operation.