Experimental study on the performance of a floating array-point-raft wave energy converter under random wave conditions

An array-point-raft wave energy converter (ARR WEC) integrating multiple-point absorption and raft type wave energy capturing technologies is proposed and experimentally investigated in this study. A 10 kW pilot device was developed, and a three-month real sea test was carried out in the Taiwan Strait, China. The experimental results confirmed the feasibility and effectiveness of the new system. The overall performance, heaving performance, power output and wave energy conversion efficiency of the pilot APR WEC running under random waves are reported and analyzed in detail. The heaving motions of the oscillating buoys and the instantaneous and average power output of the permanent magnet generator (PMG) are affected significantly by the number of oscillating buoys used to collect wave energy. More oscillating buoys used increase the production of electricity and improve the power quality, but lead to the reduction of energy conversion efficiency in long wave periods. The increase of electrical resistance of PMG results in an increased wave conversion efficiency. The experimental results obtained are valuable in the optimal design and operation of the ARR WEC system proposed.