Design and Experiment of a Novel 2-D Lookup Table MPPT for the PTO System of WECs

The power takeoff (PTO) system is the core unit of the wave energy converter (WEC). Introducing a maximum power point tracking (MPPT) for the PTO system can enhance the energy production, which is important for in-situ WECs. Traditional online MPPT algorithms encounter various challenges when applied to WEC, including lengthy processing time, diminished accuracy, and susceptibility to step size. A 2-D lookup table MPPT is proposed to better integrate MPPT with wave energy. The proposed algorithm establishes a 2-D mapping relationship in a table of the maximum power points at each generator rotational speed and external load. This algorithm distinguishes from conventional wave energy MPPT strategies by avoiding the observation of wave variables, such as period and amplitude, thereby negating the need for operational identification and offering substantial benefits in random wave scenarios. The 2-D lookup table MPPT is validated through simulation and experiments. Results show that it can improve the collection of electrical power by more than 150% compared with online MPPT, demonstrating its fast, efficient, and accurate response characteristics.