Fault ride-through for a smart rotor DQ-axis controlled wind turbine with a jammed trailing edge flap

A Smart Rotor wind turbine is able to reduce fatigue loads by deploying active aerodynamic devices along the span of the blades, which can lead to a reduced cost of energy. However, a major drawback is the complexity and potential for unreliability of the system. Faults can cause catastrophic damage and without compensation would require shutdown of the turbine, resulting in lost revenue. This is the first study to look at a fault ride-through solution to avoid shutdown of the turbine and lost revenue during a fault, while keeping additional damage to a minimum. A worst case scenario of a jammed flap with no direct knowledge of its occurrence is considered, while operating a DQ-axis Smart Rotor wind turbine. A method for detecting the fault using 1P cyclic loadings is presented, as well as two fault ride-through options: setting the remaining active flap angles to zero and setting the remaining flap angles to that of the jammed flap if known. These are analysed using IEC standard load cases. It is found that rapid detection of faults is vital for Smart Rotor controllers to avoid highly damaging cyclic loads caused by rotor imbalance, but that fault ride-through is fairly simple to implement and this allows the load benefits of the Smart Rotor to be accessible even with long fault periods.