Educational Toolkits

Free, interactive tools built by a practicing protection engineer to make the hard-to-picture parts of power systems tangible. They run entirely in your browser — nothing to install, nothing to sign up for.

Phase A Phase B Phase C

Interactive tool

Sequence Components Toolkit

A hands-on visualizer for symmetrical (sequence) components — the analytical backbone of unbalanced fault analysis. Drag the phase or sequence sliders and watch the phasors respond in real time, then see any unbalanced three-phase set resolve into its positive-, negative-, and zero-sequence networks. Step through worked fault conditions with the underlying math shown right alongside the diagram — the picture and the equations, finally in one place.

Real-time phase & sequence sliders
Positive / negative / zero decomposition
ABC & CBA rotation
Single line-to-ground & phase-to-phase faults
Polar ↔ rectangular · degree ↔ radian tools
Runs in your browser — nothing to install

Launch the toolkit → Opens in a new tab · free to use · best on desktop or tablet

Training session · interactive figures

Symmetrical Components — Session Toolkits

The interactive figures from the live Symmetrical Components tutorial, each on its own page so you can drive it yourself. Every picture is computed by the same engine used in class — so it can never disagree with the math. Best on a desktop or tablet.

01 · Transformation

See the decomposition happen

Watch a fault current resolve into positive-, negative-, and zero-sequence sets. Switch the disturbance — balanced, single line-to-ground, line-to-line, open phase — and see which sets survive.

Open the toolkit → 02 · Build it

One unbalanced set = three balanced sets

Drive the three phase phasors with the sliders and watch the balanced positive, negative, and zero sets that add up to make them — Fortescue's theorem, live.

Open the toolkit → 03 · The lab

Sequence lab — drive it yourself

The full sandbox: set the magnitude and angle of each sequence component and read the phase currents that result — or work it the other way around.

Open the toolkit → 04 · What the CT sees

Line-to-line quantities can't see zero sequence

Drive the phase currents and watch line-to-line quantities stay blind to the zero-sequence set — the reason a delta winding hides ground current.

Open the toolkit → 05 · Transformers

Where zero sequence can go through a bank

Pick a transformer winding connection and impedance, and see whether zero-sequence current passes through, sources from, or is blocked by the bank.

Open the toolkit → 06 · Solved live

The bank decides — with real numbers

The engine solves it in real time: choose HV/LV connections, clock hour, neutral impedance and core type, and read the verdict off the zero-sequence current on each side.

Open the toolkit →

These open in a new tab and run entirely in your browser. From the Symmetrical Components — Part 1 session; more toolkits will be added as further sessions are built.

More toolkits are on the way. Have one you'd find useful, or spotted something to improve? Email Doug Millner.