So many academic papers quote the following fact: "A line commutated converter in steady-state operation inherently consumes reactive power of about 60% of the DC power transferred."
I do not want to see this from "generating" or "consuming" vars' view. My real question is more like this: HVDC is causing current to phase shift from the voltage, what is causing the phase shift?
commutation process itself? or the reactive elements in filters and transformers?
I strongly believe that alpha angle in the commutation process is NOT the answer. alpha angle mask the appearance of current, it does not cause phase shift. Mask and phase shift are very different! Draw a metal picture of a diode inserted between your resistive circuit and an AC power source, current may disappear for half a cycle, but the current is still inphase with the voltage, no phase shift, no Var.
I find this frustrating, as most of you just accept the conclusions without truly understanding it.