Causal sub-optimal control of linear generators for wave power systems

This paper proposes the reactive control of a wave
energy converter (WEC) to extract power from a direct drive
linear generator in irregular waves. By introducing reactive
control at a single frequency, the motion of the WEC is generally
in phase with the incoming waves without the need for wave
prediction. The power take-off (PTO) force is provided by an
air-cored tubular machine which is directly coupled to the WEC.
The model of a WEC with reactive control is only linear when
no amplitude or force constraints are required; these must be
added to the model to see how it works in sea states that excite a
resonance response. With these constraints, the motion between
the buoy and waves becomes out of phase and the system is nonlinear.
A Matlab/Simulink time domain model is used to analyze
and simulate the system.