Symmetrical Components, Per-Unit Systems, and Unbalanced Fault Analysis: Fortescue's Transformation, Sequence Networks, Single-Line-to-Ground Faults, and Ferroresonance

Deep End Era. Engineering with Sankalp · Oct 29, 2026 · 1h 39m

An unbalanced fault breaks the simple per-phase picture of a three-phase grid. This opening power-systems episode develops per-unit normalization, Fortescue's symmetrical components, positive-, negative- and zero-sequence networks, unbalanced fault analysis and nonlinear ferroresonance.

Chapters

00:00:00 Launching Series 3

00:04:02 The Per-Unit ($pu$) System

00:11:41 Charles Fortescue's 1918 Breakthrough

00:20:26 Why Symmetrical Components Decouple a Three-Phase Grid

00:29:39 Sequence Impedances of Synchronous Generators and Transformers

00:38:18 Connecting Sequence Networks for Unbalanced…