No clear winner. The survival gap is under 10 percentage points and the balanced-score gap is under 0.05, so neither SolvSRK nor the best baseline clears the win threshold. Either works — choose on cost, licensing, or integration effort. All verdicts →
4D Single-Machine Infinite-Bus with 3-phase bolted fault. State: [delta, omega, E'q, E'd]. Transient model (Kundur Ch. 4). Fault: V(t)=0 at t=[1.0, 1.1] s. Non-segmented: RHS checks t internally. Tests SolvSRK on piecewise-constant discontinuity.
Kundur (1994) Power System Stability and Control, Ch. 4 Table 4.1; Anderson & Fouad (2003)
Canonical RHS excerpt from the registered callable used for this benchmark cell. Expand it to verify the state equations; it is not a standalone runnable fixture.
def _smib_3phase_fault_rhs(t: float, y: np.ndarray) -> np.ndarray:
"""SMIB 4-state transient model with piecewise-constant V(t).
V(t)=0 during [1.0, 1.1] s (bolted 3-phase fault); V_inf otherwise.
Pe = E'q·Iq + E'd·Id + (X'd − X'q)·Id·Iq (Kundur Eq. 3.131).
"""
delta, omega, Eq_p, Ed_p = y
V = 0.0 if _SF_FAULT_ON <= t <= _SF_FAULT_OFF else _SF_Vinf
Id = (Eq_p - V * np.cos(delta)) / _SF_Xdp
Iq = (V * np.sin(delta) - Ed_p) / _SF_Xqp
Pe = Eq_p * Iq + Ed_p * Id + (_SF_Xdp - _SF_Xqp) * Id * Iq
ddelta = _SF_ws * (omega - 1.0)
domega = (1.0 / (2.0 * _SF_H)) * (_SF_Pm - Pe - _SF_D * (omega - 1.0))
dEq_p = (1.0 / _SF_Td0p) * (_SF_Efd - Eq_p - (_SF_Xd - _SF_Xdp) * Id)
dEd_p = -(1.0 / _SF_Tq0p) * (Ed_p + (_SF_Xq - _SF_Xqp) * Iq)
return np.array([ddelta, domega, dEq_p, dEd_p])Canonical RHS excerpt captured from the same registered callable used for the published benchmark. Frozen closure values are summarized below; helper imports and solver settings are intentionally omitted.
Fingerprint
Spread: low
Default noise: low
Recommendation snapshot
Clean best: SciPy Radau
Noisy best: SciPy BDF
Coverage
14 solver arms · clean + 5 noise levels
Ranked on survival, precision, and speed
20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: SMIB 3-phase fault (4D, non-segmented) (smib-3-phase-fault-4d-non-segmented)
Governed SolvTune benchmark freeze; per-arm medians only. RHS definitions and raw trial rows are not published.
Self-reported by Resonix Labs · not independently verified
Pick an objective and a noise level to rank all arms on survival, median SCD, median nfev, and median wall time. Medians across seeds.
Objective
Best overall trade-off of survival, precision, and speed.
Noise level
| # | Solver | Survival | SCD | nfev | Wall | Score |
|---|---|---|---|---|---|---|
| 1 | SciPy RadauSciPy | 100% | 15.9 | 48 | 1 ms | 0.997 |
| 2 | SciPy BDFSciPy | 100% | 15.6 | 38 | 1 ms | 0.990 |
| 3 | CVODE BDFexternal | 100% | 14.3 | 10 | 6 ms | 0.959 |
| 4 | CVODE Adamsexternal | 100% | 14.3 | 10 | 6 ms | 0.959 |
| 5 | SciPy RK23SciPy | 100% | 12.5 | 20 | <1 ms | 0.917 |
| 6 | SciPy LSODASciPy | 100% | 12.4 | 5 | <1 ms | 0.915 |
| 7 | SciPy RK45SciPy | 100% | 9.8 | 38 | <1 ms | 0.852 |
| 8 | SciPy DOP853SciPy | 100% | 8.2 | 254 | 2 ms | 0.815 |
| 9 | Tsit5external | 100% | 7.3 | 204 | 696 ms | 0.793 |
| 10 | SolvSRK | 100% | 0.0 | 26,671 | 5.95 s | 0.619 |
At Clean, best balanced arm is SciPy Radau · SolvSRK survival 100%, SCD 0.0.
Values are medians across seeds, measured by Resonix Labs on Resonix hardware and not independently verified; nfev and wall are on reference lab hardware (indicative). Under injected noise only SolvSRK and the SciPy arms are run. How we measure accuracy → · Verification status →
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SolvSRK · 30-day trial
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Replace the access date. Pin the freeze ID and library versions when comparing against a later export. Cite it as what it is — a self-reported vendor benchmark, not an independently verified result. The note field says so; please keep it.
@misc{resonix_evidence_smib_3_phase_fault_4d_non_segmented_2026,
title = {Resonix Evidence Portal: SMIB 3-phase fault (4D, non-segmented)},
author = {{Resonix Labs (Canada) Inc.}},
year = {2026},
howpublished = {\url{https://resonix.tech/evidence/problems/smib-3-phase-fault-4d-non-segmented}},
note = {Self-reported vendor benchmark; internally generated by Resonix Labs and not independently verified. Accessed YYYY-MM-DD. Freeze 2026-08-13; libsolvsrk 2.3.0; SciPy 1.14.}
}TRL 4–5 · simulation-lab validated · 398 problems · 14 solver arms · clean + 5 noise levels
Freeze: 2026-08-13 · scipy 1.14 · libsolvsrk 2.3.0 · Methodology
Self-reported by Resonix Labs · not independently verified · Verification status