Cables are extensively used for underground alternating current electricity distribution and progressively over longer distances ; the proliferation of offshore wind farms which require interconnections with the mainland has also increased their use underwater. Models of cables are available in the well-known Electro Magnetic Transient Program software and are designed to the time-domain. These models are assembled using different techniques but all of them need a precise knowledge of the frequency domain parameters of the cables. Accordingly, for the calculation of the impedances of three-core submarine power cables this thesis proposes an improved method to consider the proximity effect between all conductors. The method, which is a semi-analytical, uses the dual concept of thin-wires and sub-conductors to describe the current density inside the conductors and the calculation of the impedances. The effect of the sea return is also analyzed and a quasi Monte Carlo method is proposed, to solve the integrals describing the impedances formulations for the two layer soil (the sea and seabed) upon which the submarine cables are laid. The effect due to the presence of semi-conducting layers in the cables is also treated. The stochastic collocation method is also described and applied, in order to account for the variability of the input parameters.
