Coupled Dynamic Analysis of a MUFOWT with Transient Broken-blade Incident

The number of wind turbines has rapidly been increased all around the world. Despite many positive aspects, the on-land and coastal wind farms also have disadvantages such as lack of available space, noise restriction, negative shade/visual impact, community opposition, and regulatory challenges. Therefore, several countries have positively considered floating wind turbines in the deeper sea. Another important concept is the Multiple Unit Floating Offshore Wind Turbine (MUFOWT). This concept includes multiple turbines upon a single floating platform, rather than the typical concept of asingle turbine on asingle floater. When properly designed, MUFOWT may reduce installation and mooring costs because only one floater is necessary for multiple turbines. MUFOWT also provides more stable and better seakeeping condition than a single-unit structure. In the case of MUFOWT, however, one wind-turbine-failure event can cause problems for other units. In this study, aone-turbine-failure event (one blade fully broken) is simulated and checked. The analysis shows that malfunction of one turbine in MUFOWT may induce appreciable changes in the performance of other turbines or the floating platform. This study can directly be applied to the development of the remote structural health monitoring system of MUFOWT in detecting partial turbine failure by measuring tower or platform responses.