Energetic Macroscopic Representation of a Marine Current Turbine System with Loss Minimization Control

This paper presents a detailed modeling along with an energetic macroscopic graphical representation of the marine current turbine (MCT) system. The MCT system under study consists of a 1.5-MW fixed pitch turbine, a permanent magnet synchronous generator, an ac-dc fully controlled machine side converter, a dc link, a dc-ac fully controlled grid-side converter, connection cables, a transformer, and the main grid. The control of each converter is designed by considering the tuning chain as a part of the system's energetic macroscopic representation. The machine side converter's control makes use of the maximum power point tracking torque control and the generator loss minimization (output maximization) techniques to enhance the overall efficiency when the system runs under the rated marine current speed. When the system runs above the base speed, the control mode is switched to the rated power limiting mode. The grid-side converter is controlled to stabilize the dc-link voltage within a certain range besides controlling the reactive power. The proposed control strategies are evaluated based on the model results by using the real data of The Alderney Race (Raz Blanchard in French) marine site.