The operation of offshore wind power plants with respect to power quality and grid code compliance must be verified for different conditions in the design phase using harmonic analysis methods. This paper addresses this verification by first considering a scenario in which wind turbines operate with a typically used modulation strategy, carrier-based pulse width modulation. The studies are performed at several operating points, not only at the rated condition, and at two points of the electrical infrastructure, at the point of connection of the wind turbine and at the point of common coupling of the offshore wind farm. For this type of modulation technique and according to the resonance conditions of the studied offshore system, the harmonic distortion of current signals is relatively high and the compliance of the German – grid code is not achieved. To tackle this, wind turbine manufacturer oriented solutions are proposed with the aim of improving the harmonic emission of the offshore wind farm. The implementation of a particular solution of selective harmonic elimination is presented together with complementary solutions to further improve the harmonic emission of the wind power facility. Furthermore, this paper discloses the modeling approach to account for an adequate harmonic assessment of the wind power plant under study.

In this paper, a Frequency-Dependent Pi Model (FDPi) of a three-core submarine cable is presented. The model is intended to be used for the representation of submarine cables in an Offshore Wind Power Plant (OWPP) scenario for both time and frequency domain analysis. The frequency-dependent variation of each conductive layer is modeled by a Foster equivalent network whose parameters are tuned by means of Vector Fitting (VF) algorithm. The complete formulation for the parameterization of the model is presented in detail, which allows an easy reproduction of the presented model. The validation of the model is performed via a comparison with a well-established reference model, the Universal Line Model (ULM) from PSCAD/EMTDC software. Two cable system case studies are presented. The first case study shows the response of the FDPi Model for a three-core submarine cable. On the other hand, the second case study depicts the response of three single-core underground cables laying in trefoil formation. This last case shows the applicability of the FDPi Model to other types of cable systems and indirectly validates the response of the aforementioned model with experimental results. Additionally, potential applications of the FDPi model are presented.

The high-power grid-connected inverter (GCI) plays a key role in integrating wind power generation. The finite control set model predictive control (FCS-MPC) has emerged as a promising high-performance control strategy for this class of power converters. However, practical stability assessment of GCI with MPC has not been fully addressed. This article investigates the stability of high-power GCI controlled by MPC and its application in offshore wind farm. The frequency scan technique is employed to derive the impedance characteristic of MPC-enabled inverter. Then, effects of MPC parameters and operating conditions on passivity are investigated. The proposed control strategy is validated and compared with classical PI-based control within Alpha Ventus offshore wind farm. Simulation and hardware-in-the-loop (HiL) verification are both implemented. The employed HiL setup integrates dSPACE DS1006 and PLECS RT Box 1, providing a versatile real-time testing platform for independent validation of the controller and plant model. The study findings show that MPC strategy can effectively mitigate oscillation phenomena and enhance stability of offshore wind farm under weak grid conditions. Hence, the proposed MPC strategy is a promising solution to promote penetration of offshore wind power generation into power system