GB/T 45906.2-2025 in English

Standard Overview and Development Background

GB/T 45906.2-2025, "Substation Secondary Systems Part 2: Data and Models," is a core component of the substation secondary system standards suite. It aims to establish a unified digital description framework to address the challenges of system integration and information silos caused by heterogeneous data models in traditional substations. This standard, in line with the development needs of new power systems, provides technical support for the intelligent transformation of substations by standardizing data representation and model construction.

Analysis of core content architecture

In-depth analysis of key technical requirements

Innovation in the data management system

The standard innovatively proposes a multi-dimensional data quality evaluation system. This system uses a combination of quality bits, including validity, invalidation reasons, source identification, test value flags, and operation lockouts, to provide a refined characterization of data quality. For example, when a measured value exceeds the data type's expression range, the overflow quality bit is set; when a limit is exceeded, the out-of-limit quality bit is set, providing advanced applications with a reliable basis for determining data status.

Unified Time Scale Specifications

Differentiated time scale annotation rules are defined for different data types: steady-state data uses the first calculation window time scale (Figure 6), dynamic phasor data uses the calculation window midpoint (Figure 7), and state variables use the transition edge time after the state stabilizes (Figure 8). This unified time scale specification solves the time synchronization challenge for multi-source data and ensures time consistency for station-wide coordinated control.

Refined Device Modeling

The standard requires that device models include three dimensions: components (physical structure), functions (logical capabilities), and interfaces (communication services). Taking a transformer as an example: a three-phase independent device requires three single-phase components, each containing subcomponents such as the insulation bushing and windings. The functional component must include logical nodes such as differential protection and overcurrent protection. The interface component defines communication service capabilities such as MMS and GOOSE.

Model configuration process standardization

The standard specifies the full life cycle model configuration process from equipment factory → engineering design → system integration → commissioning verification → acceptance archiving (Figure 11):

• Factory stage: The equipment manufacturer provides a factory model containing basic parameters and capability descriptions
• Design stage: The design unit completes the equipment naming and connection relationship definition to form a design model
• Integration stage: The whole station model configuration such as scheduling naming and communication parameters is completed through the system configuration tool
• Debugging stage: The correctness of the model is verified and corrected through joint testing
• Archiving stage: After acceptance, the model is solidified and archived as a benchmark for transformation

Dual-mode compatibility implementation solution

The standard requires that the model support both DL/T860 and CIM (GB/T 43259.301) two standards, Appendix C gives the implementation method based on DL/T860 in detail:

Implementation Recommendations and Application Outlook

Phase-based Implementation Strategy

It is recommended to adopt the implementation strategy of "pilot first, gradual promotion": first, fully apply the standard in newly built smart substations, then implement model standardization transformation in steps in renovation projects, and finally achieve unified standardization of the data model of the entire station.

Tool chain support construction

It is necessary to develop supporting system configuration tools (Section 8.2) and device configuration tools (Section 8.3) that comply with the standards. The tools should support:

• Model version management and difference comparison
• Bidirectional conversion between DL/T860 and CIM models
• Automatic generation of monitoring screen point tables based on models
• Local model modification isolation and impact analysis

Prospects for standardization benefits

Through the implementation of this standard, it is expected to achieve: the interoperability rate of equipment models will be increased by more than 80%, the engineering integration cycle will be shortened by 40%, and the operation and maintenance efficiency will be improved by 35%, laying a solid foundation for the digital twin and intelligent operation and maintenance of substations.

Conclusion

GB/T 45906.2-2025 addresses the long-standing issue of fragmented standards in substation secondary systems by establishing unified data and model specifications. Its innovative data quality system, refined equipment modeling methods, and full lifecycle configuration management process provide a complete technical framework for smart substation construction. With its implementation, the standardization level and interoperability of substations in my country will be significantly improved.