Optimizing safety supervisors for wind turbines using barrier certificates

To avoid structural damage, a wind turbine is equipped with a safety supervisor that triggers an emergency shutdown procedure in case of internal faults or large wind gusts. This paper leverages the (compositional) barrier certificate framework for the design and optimization of such a supervisor. The problem is formulated as a sum of squares problem and is solved using semi-definite programming. Both a direct and compositional approach are successfully implemented and verified for the NREL 5MW reference turbine. In conclusion, the methods derived in this paper are indeed viable for the syntheses and optimization of safety systems for future wind turbines.