An improved linear time-varying reactive hydrodynamic control for a grid-connected wave energy conversion system

Generally, a grid-connected wave energy conversion system consists of various standard stages, such as wave absorption, power take-off, and power conditioning. Each stage has a specific control objective, which may not align with the control objectives of other stages, affecting overall wave-to-grid economic performance. This study assesses a controlled grid-connected wave energy conversion system with an improved reactive hydrodynamic WEC controller, i.e. LiTe-Con+. In particular, the LiTe-Con+ adapts its constraint handling mechanism in a time-varying manner, providing improved power absorption and use of the dynamic range. Lyapunov-based nonlinear controllers are also designed for the power converters in the powertrain. The proposed system is then simulated in the MATLAB/SIMULINK environment in order to demonstrate the effectiveness of the proposed control scheme. The results show the superior performance of LiTe-Con+ compared to LiTe-Con and passive damping controllers.