Maximum Power Point Tracking Control Strategy Based on the Hydrodynamic Model of the Pendulum Wave Energy Generation System

This paper proposes a new pendulum wave energy generation device, which is a direct-drive power generation structure with a rack and pinion drive mechanism. In order to improve the power generation efficiency of the pendulum wave energy generation system (PWEGS), this paper presents a maximum power point tracking (MPPT) control strategy. Firstly, the basic conditions for maximum capture power can be solved according to the hydrodynamic model of the pendulum body. On the one hand, a resonance control method is proposed to make the system resonate with the wave in real-time so as to increase the mechanical energy captured by the device. The specific implementation mode is to change the position of the counterweight mass block according to the wave cycle, so as to change the natural cycle of the device. On the other hand, a torque control method is proposed to improve the conversion efficiency of mechanical energy to electric energy. In essence, the optimal power take-off (PTO) damping torque is generated to match the radiation damping torque of the system by controlling the torque current of the permanent magnet synchronous generator, so that the equivalent resistance of the PTO system can be consistent with the radiation damping of the system. Based on the two control methods, the PWEGS can generate the maximum power. Finally, the feasibility and accuracy of the proposed MPPT control strategy are verified by simulation results.