Symmetrical Components & Fault Visualizer

Decompose unbalanced three-phase systems into positive, negative, and zero-sequence networks — then drive fault current through them and see every sequence quantity update in real time.

AVAILABLEAUTOMATED CHECKS ONLYSTANDARDS-AWAREADVANCEDIEEEIEC 60909WHAT DO THESE STATUSES MEAN?

SEQUENCE NETWORK SOLVER4 FAULT TYPES3 GROUNDING MODES480 V – 138 kV

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Overview

Symmetrical components are the mathematical backbone of every short-circuit study, relay coordination file, and arc flash report produced today. This lab builds genuine intuition by letting you manipulate a live sequence-network solver: choose a fault type (3-phase, SLG, LL, DLG), set grounding method (solid, ungrounded, or high-resistance), adjust source strength and transformer impedance, then watch phasor diagrams, waveforms, sequence-current tables, and network block diagrams all update simultaneously. Seven tabbed workspaces cover the full topic arc — from the conceptual overview of positive/negative/zero sequences, through hands-on fault exploration and design challenges, to a graded quiz. Field-relevant presets let you jump instantly to textbook scenarios. Whether you are studying for the PE exam, preparing for a NETA certification, or building engineering intuition for a protection study, this visualizer makes abstract math tangible.

App preview

A live look at the app you'll launch — every control on the left drives the visualizations on the right in real time.

Inside the lab

Example data — not a real field report

Overview tab with a balanced (no fault) system — Overview · Balanced system — only positive-sequence current flows; negative and zero sequences are zero.

Sequences tab showing layered phasor decomposition and Fortescue transform matrix — Sequences · Layered phasor decomposition with the Fortescue transform matrix made visible.

Fault Explorer tab comparing four fault types side by side — Fault Explorer · Side-by-side comparison of every fault type, which sequences participate, and severity.

Design Challenge tab with auto-graded engineering scenarios — Design Challenge · Open-ended engineering tasks the app auto-grades against your configuration.

What you'll do

01Explain why any unbalanced phasor set can be decomposed into three balanced sequence sets
02Identify which sequence components are present for each of the four fault types (3-phase, SLG, LL, DLG)
03Trace fault current through positive-, negative-, and zero-sequence networks connected in series or parallel
04Predict how grounding method (solid / ungrounded / HRG) changes zero-sequence current and ground fault magnitude
05Read and interpret phasor diagrams and sequence-current tables in the context of a real fault study
06Apply symmetrical-components theory to protection and coordination decisions

Try a guided scenario

Move between phase quantities and sequence quantities for several fault types.

Symmetrical components and sequence networks · Power Systems Analysis

No sign-in required. Progress is saved on this device.

What this lab is not

Not a design document, stamped calculation, or approval record.
Not a substitute for engineering analysis by a licensed professional.
Not connected to live equipment and not a safety device.

Calculation basis

References IEEE, IEC 60909. Results are computed from the entered inputs and cited back to the referencing clause or table number — no code text or table is reproduced verbatim.

Simplifying assumptions are stated in the lab itself; where a model is intentionally conceptual, the lab says so rather than implying study-grade accuracy.

Standards basis: Standards-aware. Validation state: Automated checks only (last checked 2026-08-15).