Abstract
This paper investigates optimal active control schemes applied to a point absorber wave energy converter within a receding horizon fashion. A variational formulation of the power maximization problem is adapted to solve the optimal control problem. The optimal control method is shown to be of a bang-bang type for a power takeoff mechanism that incorporates both linear dampers and active control elements. We also consider a direct transcription of the optimal control problem as a general nonlinear program. A variation of the projected gradient optimization scheme is formulated and shown to be feasible and computationally inexpensive compared to a standard NLP solver. Since the system model is bilinear and the cost function is not convex quadratic, the resulting optimization problem is not a quadratic program. Results will be compared with an optimal command latching method to demonstrate the improvement in absorbed power. All time domain simulations are generated under irregular sea conditions.
Original language | English |
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Article number | 6353624 |
Pages (from-to) | 324-332 |
Number of pages | 9 |
Journal | IEEE Transactions on Sustainable Energy |
Volume | 4 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2013 |
Externally published | Yes |
Keywords
- Optimal control
- projected gradient method
- wave energy