Design and analysis of bidirectional driven float-type wave power generation system

The dynamic model for a bidirectional driven float-type wave power generation system design is presented in this paper. The gravity, buoyancy and drag force acting on the wave energy converter (WEC) are all analyzed. The analytical expression of the torque applied on the rotor is given based on a linear model of the switched reluctance generator (SRG). The SRG usually rotates with low velocity in the WEC system. In this situation, current chopping control (CCC) is adopted with fixed turn-on angle and turn-off angle control mode to have a quick response for SRG. Further, in order to make the float keep in phase with the wave so as to improve the power generation efficiency, the reference current is dynamically adjusted according to the wave motion at all working stages. Then maximum power point tracking (MPPT) of system is achieved. A simulation model is developed in MATLAB for the bidirectional driven float-type wave power generation system with real wave statistical characteristics taken into account. Simulation results show that the WEC can output desired torque periodically with high efficiency and good adaptability. Therefore, the feasibility of applying a SRG in a WEC is also verified.