Losses and Inductive Parameters in Subsea Power Cables

Four samples of galvanized steel armour for sub sea power cables are tested with an electric steel tester. The samples exhibit different remanence magnetization and permeability. The effects of permeability on loss in sub sea cables is found to be insignificant. Slight increase of conductor inductance due to increase in permeability of armour wires is observed. Mutual cancellation of inductance between circuits that are twisted opposite to each other, or with respect to one circuit, is confirmed with laboratory tests and measurements on full scale sub sea power cables. The parameters of one cable is calculated using IEC s analytical approach and found to be inaccurate for conductor resistance. The Calculations places 22% of total cable loss in the armour. Measurements on two sub sea cables and analysis using finite element method contradict the calculated armour loss. Parameters for two sub sea power cables are calculated based on measurements performed on the actual cables. The calculated values are compared with values computed using finite element analysis. Derived physics from laboratory experiments and measurements on the cables is applied in finite element analysis and found to be accurate compared with calculated values from measurements and computed values using Flux 2.5D