New management structure of active and reactive power of a large wind farm based on multilevel converter

• Modeling of the different components of the wind farm (wind turbines, gearbox and DFIG).
• Control MPPT of each turbine, Vector control of each DFIG.
• Modeling of a rotor side converter (RSC) and a grid side converter (GSC).
• DC voltage control in closed loop.
• Active and reactive power supervision using proportional distribution algorithm.

This paper proposes a system of supervision and operation of a new structure wherein a large wind farm is connected to an electrical grid. The farm is managed in such a manner that it can produce the power needed by the grid system. The supervision algorithm is used to distribute the active and reactive power references to the wind turbines proportionally. Based on the aerodynamic power and wind speed of each turbine, the active and reactive power references are produced individually. By using the vector field oriented control, each doubly fed induction generator is controlled through the rotor, which is connected to the two-level pulse width modulation converter. The close loop control is used to provide a constant DC voltage using a five-level neutral point clamped converter. The five-level neutral point clamped converter allows also the adaptation of the voltage level to the electrical grid with better resolution waveform. The analysis of the simulation results shows the effectiveness of the proposed system.