A Multi-Source Cross-Domain Data Fusion Framework for Ordinal Health-State Assessment: A Reproducible Surrogate Benchmark Motivated by Hydrogen-Cooled Turbogenerators

Real-world fault data for hydrogen-cooled turbogenerators are scarce and largely proprietary, which hinders data-driven health assessment aligned with severity standards. This paper proposes a standards-aligned, multi-source ordinal fusion framework and demonstrates it, as a proof of concept, on a reproducible four-domain surrogate collection. The collection combines public industrial datasets—SKAB (cooling loop), UCI-WWT (water chemistry), CARE Wind Farm A (electrical and thermal conditions)—and a physics-informed hydrogen-side stream derived from Henry’s law and a continuously stirred tank reactor (CSTR) mass balance, joined by paired sampling. The collection is a methodological benchmark, not a validated diagnostic for any specific machine. A dual-head classifier supervised by a hybrid CORN + EMD ordinal loss, a multi-stream fusion backbone, and a calibrated ensemble with per-model temperature scaling are aligned with the four-level GB/T 43188-2023 scheme (Normal/Attention/Abnormal/Serious). All methods are evaluated under a unified protocol (mean ± standard deviation over three seeds; the deterministic calibrated ensemble is reported as a single value). On 600 fused test samples, the ensemble reaches F1-macro 0.5349, Accuracy 0.6717, Cohen’s κ = 0.4713, and quadratic-weighted kappa (QWK) 0.5948, improving F1-macro by +22.4 pp over the strongest full-scale single-source baseline (InceptionTime on CARE, trained under the identical protocol), with larger rank-aware gains (+30.4 pp on κ, +36.2 pp on QWK). It further improves by +8.9 pp over the strongest cross-entropy fusion baseline retrained under the identical protocol. The results support the methodological claim that fusing four heterogeneous monitoring domains under rank-aware ordinal supervision yields coherent, standards-aligned severity grades, offering a reproducible benchmark and methodology whose transfer to real hydrogen-cooled turbogenerators remains to be validated on co-recorded plant data.