Control of a wind turbine for grid fault detection in stand-alone or grid-connected modes

In this study, a wind generation is considered as a unit able to supply an isolated load or to be integrated into a network coupled with classical alternators. This generator operates without auxiliary source and participates in the production-consumption balance by adjusting the provided amplitude and frequency of the voltages, through the generation or the absorption of active and reactive powers. For a smooth transition between different operation modes, a control strategy is proposed to receive measurements and operates in grid-connected or stand-alone modes with automatic switches. The transition from first to second mode corresponds to an islanding one. In this context, an algorithm, based on surveillance of the wind power, the voltage and frequency of the grid, is suggested to detect islanding in case of defects and to participate in the grid stabilization by reducing the voltage and frequency fluctuations across the injection of active and reactive powers.