Application of the optimal command method to the control of the SEAREV wave energy converter: A study on the influence of time constants on the efficiency of the latching control

This paper deals with latching control of the SEAREV ocean wave energy converter. It has been shown in previous studies that latching control could improve considerably the overall efficiency of the system, but assuming that the actuators idealy apply forces instantaneously. In reality, time constants are unavoidable in the response of the actuators and this can have an influence on the global benefit that one could expect from the control; the present study focus specifically on this issue. First, equation of motion of the SEAREV machine is written under the form of state equation by using Prony's method. Then, optimal command theory is applied in order to compute the command sequence, using a weak modelisation to describe latching control and a first order model to describe the actuators. Time domain simulations were performed, and results show that the time constants can affect strongly the global efficiency of the latching control.