DC-side harmonic compensation in DC traction applications
A problem associated with dc traction substations, is the non-robustness of the passive filters used for the filtering of the harmonics induced by the 12-pulse rectifiers. These harmonics cause problems with the communications and the signaling on the dc railway lines. Interference with the railway signaling system can have serious and sometimes fatal effects. Therefore, a method is being devised by which the problematic harmonics can be compensated for by means of an Active Power Filter (APF) on the dc-side of the 12-pulse rectifiers.