Cost-Effective Power Conversion for Wave Energy Harvesting Using Doubly-Fed Induction Generator

This work presents a wave energy conversion system incorporating a cost-effective power electronic interface designed with a minimized number of switching devices to enhance operational efficiency and reduce implementation complexity. A doubly-fed induction machine is utilized as the primary electromechanical component, providing stable performance across a broad range of wave energy conditions. To improve system responsiveness and reduce dependence on external measurement devices, an internal model-based observer is implemented for real-time estimation of rotor speed, complemented by a grid voltage estimation method that facilitates reliable synchronization and control. The complete system is developed and analyzed within both the MATLAB/Simulink and PLECS simulation environments. Simulation studies under varying grid and wave conditions confirm the effectiveness of the proposed architecture in delivering robust, efficient energy conversion and precise control. The control strategy exhibits strong adaptability to grid fluctuations and supports accurate power regulation. The system is comprehensively verified through simulation, and a series of representative case studies are presented to demonstrate and validate its performance.