Waveform-Feature-Driven Diagnosis and Physics-Constrained Self-Correction of Representative EMT Component Implementation Faults: A Multi-Agent Feasibility Study.

Latent faults in electromagnetic transient (EMT) components can alter initialization, switching-event, and history-state semantics while producing sparse or small waveform discrepancies. This study formulates a reference-model-based verification as a closed-set, waveform-guided diagnosis and constrained source-repair problem. Global, local-window, and event-level evidence rank fault mechanisms or trigger abstention. Repairs must pass compile-feasibility, behavioral-conformance, and applicability-aware physics-and-discretization audit gates. A multi-agent workflow implements this process. InvSqrt and single-phase-breaker faults were corrected to exported-waveform precision; the breaker record contained only two nonzero differences among 20,000 samples. The VARRL correction yielded 0.1% residual node-voltage RMS differences. A within-case VARRL extension across four matched conditions and three source variants exposed condition-dependent activation, a weakly separated effect of 0.018% RMS relative difference, a smaller inseparable effect routed to expert review, and a mixed-snapshot variant that reduced reference error but violated a discretization contract. An author-constructed ten-candidate challenge set spanning three component structures compiled in RSCAD FX 2.3 CBuilder; the deterministic audit returned Pass for three designed semantics-preserving refactorings, Reject for six isolated rule violations, and Expert review for one underspecified temporal convention. These results provide mechanism-level and preliminary audit-coverage evidence rather than population-level fault frequency, independent classification accuracy, general rule sufficiency, or formal verification.