Automatic Generation of Commissioning Schemes for Intelligent Substation Renovation and Expansion Based on an SCD Difference Graph and Sub-CRC Boundary Inference

In intelligent substation renovation and expansion projects, commissioning scheme preparation still depends heavily on engineering experience, which can lead to over-extended test boundaries and missed changes to virtual circuits. This paper proposes an automatic scheme generation method based on a Substation Configuration Description (SCD) difference graph and hierarchical cyclic redundancy check (CRC) boundary inference. A unified IEC 61850 intermediate model represents device, communication, and virtual link changes; IED CRC, sub-CRC, and minimum sub-CRC then refine the test boundary from devices to links and communication directions. Scenario templates, quantitative task costs, rule inference, and permission constraints are subsequently used to generate commissioning objects, tests, procedures, and safety measures. The method is evaluated on three synthetic renovation scenarios using a pre-frozen edit manifest oracle. In Case A, the representative scheme covers all four oracle devices, all three oracle link groups, and all 12 required step categories, with step completeness and step precision both equal to 1.0 and zero permission violations. Across the three cases, the method maintains complete device coverage while reducing redundant device-level tests.