Multistep Sequential Model Predictive Control of 3-Level NPC PMSG Wind Turbines

We present a novel model predictive control algorithm for three level neutral point clamped converter back-to-back PMSG wind turbine systems. In order to reduce the computational complexity we utilize a sequential approach. The wind turbine as well as the grid outputs are optimized within the outer loop. In order to reduce the computational effort a modified sphere decoder is applied. The best K solution candidates of the outer loop are then passed on to the inner loop. The DC-link balance is optimized in the inner loop. Since the number of solution candidates is comparably small for the inner loop, an exhaustive search is applied. The framework is verified by means of numerical simulations.