High-Voltage Direct Current (HVDC) Transmission: Line-Commutated (LCC) vs Modular Multilevel Voltage-Source Converters (VSC-MMC), DC Breakers, and Multi-Terminal Grids

Deep End Era. Engineering with Sankalp · Oct 29, 2026 · 1h 28m

Why convert AC power to DC for long transmission links and submarine cables? This episode compares line-commutated converters with modular multilevel voltage-source converters, then examines commutation failure, DC fault paths, hybrid breakers, multi-terminal grids and voltage-droop control.

Chapters

00:00:00 Chapter 1: Cold Open — Why a 100-Kilometer Undersea 500-kV AC Cable Chokes to Death on Its Own Capacitance—And How $\pm 1,100\text{-kV}$ HVDC Moves 12 Gigawatts Across 3,300 Kilometers!

00:06:29 Chapter 2: The Physics & Economics of HVDC vs. HVAC — Break-Even Distances, Asynchronous…