Discrete wavelet transform based protection for a wind farm double fed induction generator

In remote areas, it is always preferred to generate electricity using wind power. A double-fed induction generator has always been a good choice to generate electric power from wind. It is not easy to detect internal short circuits on stator windings especially for those occurring within a few turns of the stator windings. The short circuit currents flowing in such cases cannot be determined by traditional relaying systems. In this paper a new simulation technique that can successfully identify internal winding failures is being introduced. The simulation is done via EMTP-ATP simulation programs. The performance of the double-fed induction generator during transient conditions including internal windings short circuits has been studied. The simulation uses discrete wavelet transform to extract features from the stator current, where a threshold value is set based on a set of training data obtained from simulation. The proposed algorithm proved to be accurate, reliable with much low computational burden.