Tool
Fault Analysis Lab
Symmetrical-components short-circuit analysis for a source-transformer-cable feeder — pick a fault type, location and resistance, and see the resulting three-phase current and voltage waveforms and phasors, before and after the fault.
Basitçe
Bir güç hattında bir şeyler ters gittiğinde elektriksel olarak ne olacağını simüle eder — bir kablonun toprağa değmesi, ya da iki iletkenin birbirine değmesi gibi. Ne kadar akım akacağını ve yakındaki gerilimin nasıl görüneceğini hesaplar — elektrik mühendislerinin onlarca yıldır elle kullandığı aynı standart yöntemle (simetrik bileşenler) — sadece anında ve kağıt yerine görsel olarak.
Network & fault
01 / inputOne phase to ground — by far the most common fault type in practice (≈70-80%).
Assumed Dyn (delta HV, grounded-star LV) — the standard arrangement for HV/MV distribution transformers, and the reason the grid source doesn't appear at all in the zero-sequence path below.
R, X — left to right.
0.121 kA fault current
Line-ground fault, 40% along the line — equivalent MVA at the largest phase current ≈ 4 MVA.
Reading point
02 / readoutRight at the fault location itself.
IA
0.121 kA
∠-89°
IB
0.000 kA
—
IC
0.000 kA
—
I0 (ground)
0.040 kA
VA
0% nom.
—
VB
171% nom.
∠-149°
VC
171% nom.
∠150°
Min. voltage
0%
Waveform & phasors
Solid = during fault, at At the fault. Dashed = pre-fault.
How this is built: symmetrical- components fault analysis (Fortescue transform + sequence networks) — the same closed- form method used in fault studies and relay-testing tools, not an iterative power flow. Positive- and negative-sequence impedances are treated as equal throughout; the transformer's zero-sequence impedance is assumed equal to its positive-sequence impedance; pre-fault load current is neglected (standard practice for a maximum fault- current study — it's also why MP2, downstream of the fault, reads ~0 current here). The transformer is assumed Dyn, so the grid source never enters the zero-sequence path — only the transformer and its grounding impedance do. Per-unit values referred to a fixed 100 MVA system base internally; every result shown is scaled back to real kV/kA, so the choice of base has no effect on any number above.
Further reading
- J. J. Grainger & W. D. Stevenson Jr., Power System Analysis, McGraw-Hill — symmetrical components and fault current calculation.
- J. D. Glover, M. S. Sarma & T. J. Overbye, Power System Analysis and Design, Cengage Learning — sequence networks and per-unit fault studies.
- IEC 60909-0, Short-circuit currents in three-phase AC systems — Part 0: Calculation of currents — the industry standard this engine's method follows in spirit, though this tool computes exact fault currents rather than IEC 60909's standardized correction-factor approximations.