Safety Evaluation of a Hybrid Substructure for Offshore Wind Turbine

Table 4

Design load cases (DLC) for ultimate limit state.

DLC	Condition	Wave	Wind
1.1	Power production	Normal	Normal
1.3	Power production	Normal	Extreme
1.4	Power production	Normal	Extreme
1.5	Power production	Normal	Extreme
1.6a	Power production	Severe	Normal
2.1	Power production + control system fault	Normal	Normal
2.2	Power production + occurrence of fault	Normal	Normal
2.3	Power production + loss of electrical grid connection	Normal	Extreme
4.2	Normal shut-down + deterministic gust	Normal	Extreme
5.1	Emergency shut-down	Normal	Normal
6.1a	Idling	Extreme	Extreme
6.2a	Idling with grid loss	Extreme	Extreme
6.3a	Idling with extreme yaw misalignment	Extreme	Extreme
7.1a	Idling with pitch failure	Extreme	Extreme
8.1	Transport, assembly, maintenance, and repair	Normal	15 m/s