Control of Variable-Speed Type Wind Turbines Using Direct Power Control Space Vector Modulated 3-Level PWM Converter

This paper presents implementation of system for variable-speed wind turbine based on permanent magnet synchronous generator (PMSG). System consists of six-pulse diode rectifier, dc/dc boost converter and 3-level neutral point clamped (npc) converter. Control scheme is mainly based on active and reactive power loops and contains following additional blocks: virtual flux and filter-capacitor voltage estimators for sensorless operation, active damping (AD) of possible resonances in LCL filter connecting converter to the grid, PWM modulator with DC link voltage balancing and minimization of switching losses. It is shown that the proposed control method exhibits several features as: sensorless operation, robust algorithm, minimization of switching losses as well as simple tuning procedure of AD. Simulation and experimental results have proven a good performance and verified the validity of the proposed system.