Adaptive fault type classification for transmission network connecting converter-interfaced renewable plants

Fault ride through compliance as imposed by the grid codes (GCs) prevents the inadvertent disconnection of the renewable plants from the network even during faults. Control algorithms applied in the converters associated with such plants modulate the fault characteristics significantly and result in malfunction of available fault type classifiers at times. In this article, an adaptive fault type classification technique is proposed for transmission network connecting converter-interfaced renewable plants. The method calculates sequence current angles in the faulted loop by determining pure-fault impedance of the plant at every instant during fault using local voltage and current data for fault type identification. The proposed method is tested for different fault situations on renewable integrated standard systems using PSCAD/EMTDC. The performance of the proposed method is found to be accurate in the presence of different types of renewable plants and complying different GC requirements. Comparative assessment reveals its superior performance