The raft-type wave energy converter (WEC), consisting of several hinged rafts and hydraulic power take-off (PTO) systems, captures wave power in a line absorber manner, whose scattered and radiated wave pattern is different from that of a point absorber. This paper focuses on the latching control of a raft-type WEC consisting of two rafts and a hydraulic PTO system. To reduce the complexity of finding the optimal latching duration, the hydraulic PTO system is modelled as a Coulomb damping and the optimal latching control law is derived from a Coulomb damping-based model using the optimal control theory. The effectiveness of latching control on improving power capture ability of the raft-type WEC with a hydraulic PTO system and the benefit introduced by latching control in terms of power improvement are investigated. Results show that the optimal latching control law derived from the Coulomb damping-based model can effectively improve the power capture ability of the raft-type WEC with a hydraulic PTO system. The benefit due to latching control can reach a peak value of 3.04, which is 2 times that introduced by load control. Moreover, latching control can further benefit the raft-type WEC where load control has been performed.

筏式波浪能转换器（WEC）由多个铰接筏和液压动力输出（PTO）系统组成，以线吸收器的方式捕获波浪能，其散射和辐射波模式与点吸收器不同. 本文重点研究由两个筏子和一个液压 PTO 系统组成的筏式 WEC 的闭锁控制。为了降低寻找最优闭锁持续时间的复杂性，液压动力输出系统被建模为库仑阻尼，最优闭锁控制律是使用最优控制理论从基于库仑阻尼的模型中推导出来的。研究了闩锁控制在提高带有液压 PTO 系统的筏式 WEC 的功率捕获能力方面的有效性，以及闩锁控制在功率提高方面带来的好处。结果表明，基于库仑阻尼模型推导出的最优闭锁控制律可以有效提高带液压PTO系统的筏式WEC的功率捕获能力。锁存控制带来的收益可以达到峰值3.04，是负载控制带来的收益的2倍。此外，闩锁控制可以进一步使已执行负载控制的筏式 WEC 受益。