What is this symbol that looks like a 3/4 circle connected to wires?
If you look further in the publication, you will find that it is a smoothing reactor.
In skimming through the document, I didn't see an explicit statement about the reactor being adjustable, but they did mention something about them being constructed with a number of "partial turns." They do say that the capacitor banks are tuned.
It is a choke (inductor).
Symbol comes from IEC60617 Symbols.
