IEEE 39-bus swing equations
DISADVANTAGES1 · dim 20A baseline wins. At the comparison noise level, the best baseline beats SolvSRK by at least 10 percentage points of survival, or by at least 0.05 balanced score when survival is tied. Use the winning baseline named on the problem page - not SolvSRK. All verdicts →
10-generator swing ODE with fault clearing; transient stability benchmark
Problem definition
Canonical benchmark implementation
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.
Show canonical RHS excerpt
def rhs(t: float, y: np.ndarray) -> np.ndarray:
delta = y[:n_gen]
omega = y[n_gen:]
P_e = np.zeros(n_gen)
for i in range(n_gen):
for j in range(n_gen):
if B[i, j] > 0:
P_e[i] += E[i] * E[j] * B[i, j] * np.sin(delta[i] - delta[j])
P_m_eff = P_m.copy()
if fault_time <= t <= fault_time + fault_duration:
P_m_eff[0] = 0.0
ddelta = omega - omega_s
domega = (P_m_eff - P_e - D * (omega - omega_s)) / M
return np.concatenate([ddelta, domega])- Parameters
- B = [0, 5, 0, 0, 0, 0, …] [shape=(10, 10), min=0, max=5]
- D = [0.04, 0.04, 0.02, 0.02, 0.02, 0.02, 0.02, 0.02, 0.02, 0.02]
- E = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
- M = [0.0265258238486, 0.0229713634529, 0.0237140865207, 0.0189394382279, 0.0229713634529, 0.0230774667483, 0.0200004711819, 0.018408921751, 0.0183028184556, 0.0222816920329]
- P_m = [2.5, 5.45, 6.5, 6.32, 5.6, 6.38, 2.8, 5.4, 0.7, 8.95]
- fault_duration = 0.1
- fault_time = 1
- n_gen = 10
- omega_s = 376.991118431
- Initial condition
- y(0) = [0.252680255142, 0.576389114736, 0.707584436725, 0.684131254766, 0.594385800001, 0.691898182137, …] [shape=(20,), min=0.0700572930881, max=376.991118431]
- Horizon
- t ∈ [0, 5]
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: extreme
Default noise: low
Recommendation snapshot
Clean best: SolvSRK
Noisy best: SciPy BDF
Coverage
14 solver arms · clean + 5 noise levels
Ranked on survival, precision, and speed
Versions & freeze
Methodology →- Freeze
- 2026-08-13
- libsolvsrk
- 2.3.0
- SciPy
- 1.14
- SUNDIALS
- CVODE (bundled backend)
20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: IEEE 39-bus swing equations (ieee-39-bus-swing-equations)
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
Results matrix
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 | SolvSRK | 100% | 9.1 | 6,559 | 126 ms | 0.836 |
| 2 | SciPy RadauSciPy | 100% | 8.3 | 7,656 | 388 ms | 0.817 |
| 3 | Vern7external | 100% | 7.8 | 3,282 | 3.82 s | 0.805 |
| 4 | SciPy LSODASciPy | 100% | 7.6 | 1,859 | 67 ms | 0.800 |
| 5 | Vern9external | 100% | 7.4 | 3,986 | 3.86 s | 0.796 |
| 6 | SciPy DOP853SciPy | 100% | 7.3 | 2,402 | 90 ms | 0.793 |
| 7 | SciPy RK45SciPy | 100% | 7.0 | 2,792 | 107 ms | 0.785 |
| 8 | Tsit5external | 100% | 6.8 | 2,742 | 998 ms | 0.781 |
| 9 | FBDFexternal | 100% | 6.4 | 2,376 | 4.77 s | 0.772 |
| 10 | SciPy BDFSciPy | 100% | 6.3 | 2,476 | 160 ms | 0.769 |
| 11 | CVODE Adamsexternal | 100% | 6.2 | 1,101 | 48 ms | 0.766 |
| 12 | CVODE BDFexternal | 100% | 6.0 | 1,631 | 68 ms | 0.763 |
| 13 | SciPy RK23SciPy | 100% | 5.8 | 6,803 | 273 ms | 0.758 |
| 14 | TRBDF2external | 100% | 3.3 | 4,542 | 4.99 s | 0.697 |
At Clean, best balanced arm is SolvSRK.
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 →
Cite this page
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_ieee_39_bus_swing_equations_2026,
title = {Resonix Evidence Portal: IEEE 39-bus swing equations},
author = {{Resonix Labs (Canada) Inc.}},
year = {2026},
howpublished = {\url{https://resonixusa.com/evidence/problems/ieee-39-bus-swing-equations}},
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.}
}Related
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