Comparison of Different Configurations for a Shoreline Pond Electrode Station in the Case of an HVDC Transmission System—Part II: Electric Field Study for Frames of Non-Linear Novel Electrode Arrangement Based on a Simplified Analytical Model

According to CIGRE, the usual arrangement of electrodes in a shoreline electrode station for HVDC interconnections is straight with the following form: forming straight frames with the electrodes at equal distances and placing the frames parallel to the longitudinal axis of the breakwater, successively at fixed distances between them. In a previous paper by the authors, 10 alternative configurations of placement of such straight frames were examined to determine which placements mainly affect the near-field results. In particular, radial or circumferential arrangements of the straight frames on a central base in the open sea improve the overall field results, such as the absolute potential and electrode station resistance to remote earth, satisfying the requirements of the maximum electric field strength. In this paper, the nonlinear configuration of the frames will be studied from an electric field perspective at the level of a preliminary study forming innovative configurations in order to check their suitability with respect to the relevant requirements of the CIGRE guidelines B4.61/2017. These arrangements, located in electrode stations, are evaluated and compared with the older configurations for two cases, those of Korakia in Crete and Stachtoroi in Aegina, Attica, for the HVDC Crete-mainland Greece interconnection of 1 GW, ±500 kV.