Transmission lines
Lumped models, ABCD parameters, surge impedance, SIL, Ferranti.
Lessons
Transmission line modeling — short, medium-π, long with ABCD
Three lumped models by length, the hyperbolic ABCD form, surge impedance Z_c, SIL = V_LL²/Z_c, and the Ferranti effect on long lightly-loaded lines.
HVDC fundamentals — LCC vs VSC, configurations
When HVDC beats HVAC (long OHL, async tie, subsea cable). LCC (thyristor, ±800 kV / 8 GW) vs VSC (IGBT MMC, black-start, 4-quadrant). Configurations and notable installations.
Insulation coordination + BIL + surge arresters
BIL (Basic Insulation Level), MOV surge arresters (MCOV / V_pr), coordination margin (BIL − V_pr) / V_pr ≥ 20-25%. IEEE 1313 / IEC 60071 standards. Lightning vs switching surges; arrester placement within 60-80 ft of equipment.
FACTS devices — SVC / STATCOM / TCSC / UPFC
Flexible AC Transmission Systems: SVC (TCR + TSC, harmonics, Q ∝ V²), STATCOM (VSC MMC, fast, constant I at low V), TCSC (series cap + TCR for power-flow control + SSR damping), UPFC (full P+Q+V independent control via shunt + series VSC pair).