Stator Harmonic Current Compensation Method for a DFIG Connected to a Distorted Grid Through Proper Adjustment of Linear Rotor Current Controllers
Gustavo Figueiredo Gontijo1; Thiago Cardoso Tricarico1; Felipe Dicler1; Matheus Soares da Silva1; Leonardo Francisco da Silva1; Mauricio Aredes1
1 Universidade Federal do Rio de Janeiro
Baixar PDF doi:10.20906/CPS/CBA2018-0014
Resumo
The DFIG is highly attractive to the wind power industry due to its technical and economic advantages. However, the fact that its stator is directly connected to the electrical grid leads to serious power quality issues that are making the DFIG market share reduce, considerably, in the last few years. For instance, if the grid voltage is distorted the generator stator current will be distorted leading to loss in the system efficiency, to undesired torque pulsations and the system might be unable to comply with grid codes regarding harmonic current injection. Many different control strategies and converter topologies have been proposed aiming at mitigating these harmonic currents. Most of the techniques are based on the addition of extra, dedicated controllers besides the usual linear controllers that regulate the rotor current fundamental component. This paper develops a stability analysis, based on the linear control theory, aiming at designing the usual rotor current controllers in such a way that they are enough to compensate for stator harmonic current components. In other words, the linear controllers will be designed so that they have a frequency response characteristic that both maintain their good dynamic behavior and compensate for stator harmonic currents.
Palavras-chave: DFIG; Stability analysis; Harmonic current compensation