4.2. WEC Power Take-Off System
The WEC Power Take-Off (PTO) system shall be represented by a linear spring-damper system that is
connected to the FOWT in the heave DOF.
4.3. WEC Natural Frequency and Stiffness
Since in this study the only excitation force is being imparted on the WEC by the FOWT, the stiffness
of the PTO system shall be set such that the natural frequency of the WEC matches that of the FOWT for
Cases 1, 2 and 3 (cf. Table 2). As discussed by literature (e.g. [10]), by matching the natural frequency of
the excited body to that of the excitation force, the induced motion shall be greatest. The PTO stiffness,
KPTO for each case is given in Table 2.