Short-term wind power forecasting using adouble-stage hierarchical ANFIS approachfor energy management in microgrids

In this work, a directional relaying algorithm is proposed for transmission line to prevent relay maloperation duringcoupling capacitor voltage transformer (CCVT) subsidence transient. The effect of CCVT subsidence transient duringsingle-pole-tripping condition is highlighted in this paper. The proposed method which is based on phaseangle difference of post fault and prefault positive sequence current can help the directional relay to takeaccurate decision during erroneous CCVT secondary response. The available CCVT model in PSCAD is not ableto generate significant subsidence transient in the secondary side. So, a new CCVT model is developed inEMTDC/PSCAD domain for transient response analysis and to check the relay operation. Next, the performance ofdifferent voltage and current information based directional relaying techniques have been analyzed and comparedwith the proposed method. The results are evaluated for different system and fault conditions. Results demonstrate theaccuracy of the proposed method.