No abstract

To maximize the generated output power under random waves, the control strategy of maximum power point tracking (MPPT) is incorporated in point-absorbing type wave energy converter (WEC) system. However, due to the influence of mutative wave conditions, the curve of the maximum average power appears in multiple peaks, adding complexity to the tracking process. This paper proposes a new MPPT control technique for a wave power generation system, by using the flower pollination algorithm (FPA) instead of the conventional hill-climbing method. Compared with the hill-climbing method, this method has advantages of achieving a smaller peak-to-average ratio and capturing the more average power under the same sea state. The verification has been carried out through the simulations and the experimental results on a lab test bench.

No abstract

A reluctance lead screw (RLS) is proposed in this paper which consists of a rotor and a translator, forming a magnetic device that is able to transfer low-speed linear motion into high-speed rotational motion. Permanent magnets (PMs) are only installed in the rotor, making it more suitable for long-stroke applications. The design aspects are assessed by finite element analysis (FEA) and the performance is evaluated. In addition, the thrust force per magnet volume is presented for evaluating the utilization rate of the PMs. The simulation results show that RLS has an advantage in terms of the PM utilization rate. A new method for realizing spiral magnets has also been developed which can not only reduce the manufacturing difficulties, but also ease the installation work. Finally, based on the simulations and analyses, two RLS prototypes designed for wave energy converters (WECs) are presented to show the potential applications of this novel topology.

No abstract