1. Optimal Active Control and Optimization of a Wave Energy Converter
- Author
-
Eric C. Kerrigan and Edo Abraham
- Subjects
Mathematical optimization ,Quadratic equation ,Optimization problem ,Renewable Energy, Sustainability and the Environment ,Control theory ,Bilinear interpolation ,Quadratic programming ,Solver ,Linear-quadratic-Gaussian control ,Optimal control ,Mathematics ,Nonlinear programming - 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.
- Published
- 2013