Abstract: A land electrode has at least one feeding element connected to an electrode line of a high voltage direct current (HVDC) transmission system. The land electrode is in electric contact with a conducting medium and further comprises at least two electrically non-conducting element barriers, spaced apart along the feeding element. Between the element barriers, an active part of the surface of the feeding element is formed, which active part is in electric contact with the conducting medium. The element barriers have a substantial extension outwards from the active part of the surface of the feeding element into the first conducting medium, so as to homogeneize the current distribution along the active part of the surface of the feeding element.

Abstract: A sea electrode (15) for grounding of a high voltage direct current transmission system comprises an electrically conducting electrode body (1) for connection to the transmission system and at least one ballast (4) located above the electrode. The electrode further comprises a layer (5) of an electrically non-conducting material, located above the electrode body and extending over it, so as to influence the maximum electrical field strength not to exceed a desired level at a point (P) at the edge of the non-conducting layer and thereby also in the sea water outside a zone (35) located below the non-conducting layer and in a vertical direction limited by the edge of the non-conducting layer.

Abstract: An electrode for use in electro-chemical corrosion protection systems, such as cathodic and anodic metal corrosion protection, is in electric contact with a ionically conducting medium. It comprises at least two electrically non-conducting barriers, spaced apart along the electrode. Between the barriers an active part of the surface of the electrode is formed, which active part is in electric contact with the conducting medium. The barriers have a substantial extension outwards from said active part of the surface of the electrode into the conducting medium, so as to homogeneize the current distribution along said active part of the surface of the electrode. (FIG.