This paper addresses the mathematical modelling
of the relationship between the free surface elevation (FSE) and
the excitation force for wave energy devices (excitation force
model). While most studies focus on the model relating the
FSE to the device motion, the excitation force model is required
to complete the mathematical wave energy system description
and also plays an important role in excitation force observer
design. In the paper, a range of linear and nonlinear modelling
methodologies, based on system identification from numerical
wave tank tests, are developed for a range of device geometries.
The results demonstrate a significant benefit in adopting a
nonlinear parameterisation and show that models are heavily
dependent on incident wave amplitude
