Adaptive Zone-2 Distance Protection Scheme for Multi-Terminal Line Connecting Wind Farm

Abstract: Wind energy is one of the fastest growing renewable sources in the world that converts wind power into the electricity through wind farms. Stochastic nature of the wind power makes interconnection of wind farms to the grid unreliable. Thus, in order to enhance the system stability, it is important to protect different parts of the power system specifically transmission lines. Since distance relays are the primary devices in the protection of lines, adjusting their setting is a crucial issue in terms of mitigating the rate of disruption and increasing the overall stability. In this paper, the impact of wind speed variation in the second zone of the distance relay has been studied. To monitor distance relay operation part of a power system is simulated in PSCAD/EMTDC. Then, an adaptive Technique is proposed to coordinate zone-2 operation in accordance to other zones and prevent over/under reach. This method is based on the Neural Network in MATLAB Simulink to adjust the second zone automatically due to occurring instantaneous changes in the grid.