DC choke arrangement of a power transformer, especially of a frequency converter, provided with a DC circuit and connected to an AC electricity network, to limit the harmonics of the network current taken by an appliance from the AC network, in which DC choke arrangement is at least one choke (Ldc+, Ldc-), which is arranged in the magnetic core, which contains pillar parts and yoke parts (1a', 1 b', 2a', 2b'), in which one or more permanent magnets (51) are arranged in the magnetic core of the choke, and in which the permanent magnet is positioned at an angle with respect to the longitudinal direction of the part or parts of the magnetic core such that the cross-sectional area of the permanent magnet is greater than the cross-sectional area of the part of the magnetic core in question or the parts of the magnetic core in question.