A comparison of fault-tolerant control strategies for a PMSG-based marine current turbine system under generator side converter faulty conditions

This paper describes fault-tolerant control strategies for a Permanent Magnet Synchronous Generator (PMSG)-based Marine Current Turbine (MCT) dealing with the generator-side converter under faulty conditions. MCT system mainly used PI controllers. However, this type of controllers is very sensitive to faulty conditions such as an open circuit faults in the generator-side converter. As consequence, the MCT system represents a high decrease in its power generation and dynamic performances. In this faulty context, firstly, a fault tolerant structure consists in requiring only minimum hardware modifications to the converter is proposed. In the second part, a backstepping and a second-order sliding mode nonlinear control are therefore investigated for fault-tolerant control purposes. A comparison between the different control strategies is proposed to prove the most robust one.