High Voltage DC Transmission

A: A: The symbol doesn’t imply load-break; that’s a different contact depiction. B: The earth is tied to the mechanism, not the blade. That leaves the conductor floating. That’s a shock hazard and a DFMEA miss. C: Dashed here denotes mechanical linkage, not optional function. Procedures don’t bleed charge. D: Reactor placement varies by topology; that’s not the defect being drawn.

A: A: MI handles voltage, but the thermal limit at 1.8 kA in that soil is the blocker. B: This is what the duty points to; DC-tested XLPE and thermal calcs line up. C: AC thermal margin doesn’t translate to DC space charge behavior. D: Pipe-type brings leakage and permitting pain without solving the soil resistivity issue.

A: A: Current didn’t change, ripple did. Saturation would show a DC offset issue. B: Pulling a filter bank does exactly this; the reactor now eats more harmonic content. C: PLL instability shows angle noise, not selective DC ripple growth. D: AC harmonics are already blocked by the transformer leakage and filters.

A: A: Cooling matters, but not before you energize insulation. B: Missing grading or leftover grounds will skew results or cause damage. This is step zero. C: Fiber checks come later; they don’t affect hipot stress. D: Humidity is recorded, not a gate to energization.