Direct Power Control for Doubly-Fed Induction Generator Using Indirect Matrix Converters

In this paper a novel DPC strategy for Doubly-Fed Induction Generation (DFIG) based wind energy generation system with Indirect Matrix Converter (IMC) is proposed. The DPC with IMC deals with several main characteristics which makes it very suitable for DFIG. By suitably selecting switching pattern, the strategy is able to improve the steady state and transient response behaviors of the machine. This paper investigates the use of four-step commutation in rectifier stage of indirect matrix converters to reduce losses and input currents waveform distortion caused by circuit snubber. Using this proposed strategy, the advantages of the DPC schemes and the benefits of the indirect matrix converters can be combined. it will be shown that by use appropriate indirect space vector modulation in IMC the harmonics are reduced considerably. Simulation results of a 2 MW DFIG system demonstrate the effectiveness of the proposed control strategy during variations of active and reactive power.