PROCESS AND DEVICE FOR DETERMINING THE ORDINAL NUMBERS OF NON-CHARACTERISTIC HARMONIC CURRENTS AND FOR COMPENSATING THE SAME

摘要

A process and device (4) are disclosed for determining the ordinal numbers (z) of non-characteristic harmonic currents (Ih) in a second energy supply network (8) coupled to a first energy supply network (6) by a HVDC system (2) and to compensate said non-characteristic harmonic currents (lh) due to a harmonic distorsion (Uh) of the supply voltage (U1) caused when low-frequency harmonics in the first network (6) are transmitted through the close connection (2). The ordinal number (n) of the non-characteristic harmonics is determined by measuring the network (6) current and/or voltage (U1). The ordinal number (z) of the generated non-characteristic harmonics in the second network (8) is then derived from the ordinal number (n) by means of a voltage symmetry signal (SMG) and is supplied to filtering logics (54) of a compensating device (44). The energy quality, in particular of non-rigid networks, is thus substantially improved.