Abstract: A plant for transmission of high voltage direct current is coupled to an alternating current network (3) with a fundamental frequency (.function.), and has a control equipment (CEQ) and a direct current link (5). A device (76) for damping an oscillation in a current (ID) in the direct current link at a frequency equal to the fundamental frequency has means (81) for generating reference signals (SSIN, SCOS ) oscillating with an influenceable reference frequency (.function..sub.R), and means (821, 822,-831, 832, 84, 85, 86) for forming an actuating signal (SAS), oscillating with the reference frequency (.function..sub.R), and with a phase position equal to the sum of an adjustable phase angle displacement (.sigma.) and of a phase position (.phi.) of the oscillation in the current in the direct current link in relation to a voltage (UC) of the alternating current network. The device further has means (107) for forming a control signal (.alpha.