GRIDRA
Labs

Lab

IEEE 39-Bus Power Flow

A full Newton-Raphson AC power flow on the canonical IEEE 39-bus (New England) test system — bundled with the standard model data. Scale the load, switch any line out for an N-1 study, toggle generator Q limits, and see bus voltages, line loadings and system losses on the single-line diagram.

Einfach erklärt

Das IEEE-39-Bus-System ist ein kleines Standardmodell eines realen Stromnetzes (New England), mit dem Ingenieure weltweit Verfahren testen. Dieses Tool löst dessen „Lastfluss": Aus der Einspeisung jedes Generators und dem Verbrauch jeder Last berechnet es die Spannung an jedem Knoten und die Leistung auf jeder Leitung — mit demselben iterativen Verfahren (Newton-Raphson), das auch kommerzielle Software wie PowerFactory nutzt. Du kannst die Last erhöhen oder senken, eine beliebige Leitung abschalten, um zu sehen, ob das übrige Netz das verkraftet (eine „N-1"-Prüfung), und beobachten, wie Spannungen und Leitungsauslastungen im Diagramm reagieren.

100%

Converged in 4 iterations

Newton-Raphson, mismatch 3.3e-11 p.u.

Slack gen

678 MW

Total loss

43.6 MW

Total load

6,254 MW

Worst line loading

76%

Voltage range

0.982–1.064 p.u.

1 bus above 1.06 p.u. (highest 1.064).
The slack generator at bus 31 supplies 678 MW, above its 646 MW rating — it is covering the extra losses of this loading. In operation, other units would be redispatched to take that share.
Buses39Branches46 (12 transformers)Generators10Base100 MVATotal load6,254 MWTotal generation6,298 MW
Line 1–2 · 178 MVA · 30% · click to toggleLine 1–39 · 76 MVA · 11% · click to toggleLine 2–3 · 332 MVA · 67% · click to toggleLine 2–25 · 258 MVA · 53% · click to toggleLine 2–30 (transformer) · 290 MVA · 33% · click to toggleLine 3–4 · 119 MVA · 28% · click to toggleLine 3–18 · 43 MVA · 9% · click to toggleLine 4–5 · 197 MVA · 33% · click to toggleLine 4–14 · 270 MVA · 54% · click to toggleLine 5–6 · 539 MVA · 45% · click to toggleLine 5–8 · 343 MVA · 38% · click to toggleLine 6–7 · 461 MVA · 51% · click to toggleLine 6–11 · 325 MVA · 68% · click to toggleLine 6–31 (transformer) · 675 MVA · 39% · click to toggleLine 7–8 · 219 MVA · 24% · click to toggleLine 8–9 · 137 MVA · 15% · click to toggleLine 9–39 · 42 MVA · 11% · click to toggleLine 10–11 · 336 MVA · 56% · click to toggleLine 10–13 · 324 MVA · 54% · click to toggleLine 10–32 (transformer) · 659 MVA · 76% · click to toggleLine 12–11 (transformer) · 42 MVA · 9% · click to toggleLine 12–13 (transformer) · 46 MVA · 9% · click to toggleLine 13–14 · 317 MVA · 53% · click to toggleLine 14–15 · 65 MVA · 11% · click to toggleLine 15–16 · 312 MVA · 52% · click to toggleLine 16–17 · 228 MVA · 38% · click to toggleLine 16–19 · 455 MVA · 76% · click to toggleLine 16–21 · 330 MVA · 55% · click to toggleLine 16–24 · 106 MVA · 18% · click to toggleLine 17–18 · 199 MVA · 33% · click to toggleLine 17–27 · 50 MVA · 8% · click to toggleLine 19–20 (transformer) · 175 MVA · 19% · click to toggleLine 19–33 (transformer) · 631 MVA · 71% · click to toggleLine 20–34 (transformer) · 519 MVA · 59% · click to toggleLine 21–22 · 611 MVA · 69% · click to toggleLine 22–23 · 60 MVA · 13% · click to toggleLine 22–35 (transformer) · 667 MVA · 76% · click to toggleLine 23–24 · 354 MVA · 59% · click to toggleLine 23–36 (transformer) · 559 MVA · 63% · click to toggleLine 25–26 · 68 MVA · 13% · click to toggleLine 25–37 (transformer) · 542 MVA · 60% · click to toggleLine 26–27 · 266 MVA · 45% · click to toggleLine 26–28 · 142 MVA · 25% · click to toggleLine 26–29 · 192 MVA · 34% · click to toggleLine 28–29 · 349 MVA · 59% · click to toggleLine 29–38 (transformer) · 829 MVA · 69% · click to toggle11.03921.04831.03141.00451.00661.00870.99880.99891.038101.018111.013121.001131.015141.012151.016161.033171.034181.032191.050200.991211.032221.050231.045241.038251.058261.053271.038281.050291.050301.050310.982320.984330.997341.012351.049361.064371.028381.027391.030
V near nominal V marginal V / loading violation slack bus generator bus· click a line to switch it out (N-1), click a bus for detail

How this is built: the network is the canonical IEEE 39-bus ("New England") test system, transcribed verbatim from MATPOWER's case39 (100 MVA base, 39 buses, 46 branches, 10 generators). It's solved with a standard polar-form Newton-Raphson AC power flow — the same routine MATPOWER, pandapower and PYPOWER run underneath — verified in this project's test suite to reproduce the published solved case (every bus voltage within 1e-3 p.u., losses ~43.6 MW). Generator Q-limit enforcement is optional and off by default, matching the canonical case. The load slider scales every generator's dispatch by the same factor, so the slack machine only covers the change in losses rather than the whole change in demand. This is the steady-state power flow phase — the same network and diagram also drive the classical-model transient stability study in the companion tool below.

Explore: IEEE 39-Bus Transient Stability

Apply a fault to this same network and watch every generator's rotor angle swing — including a critical clearing time finder.

Further reading