Power Swing and Fault Detection in the Presence of Wind Farms Using Generator Speed Zero-Crossing Moment

Nowadays, due to the entry of wind power plants into the power systems, which causes changes in the network parameters, power swing detection has become more important. Changes in the wind speed and noncontinuity of the wind power plants lead to changes in the power swing characteristic. Therefore, the impedance seen by the distance relay is changed, and so the maloperation of the relay during the stable power swing may occur. This paper proposes a new method to detect power fluctuations based on the synchronous generator speed while it is independent of the network parameters. Based on the proposed method, the generator speed at any moment does not pass through zero during the stable power swing. In contrast, it passes through zero by occurring fault types with high and low fault resistance, fault types during power swing, and an unstable power swing. Therefore, the method prevents maloperation of distance protection. It is worth noting that the proposed method is applicable for distance protection in any power system with and without wind power plants, such as in the distance protection of compensated transmission lines. The obtained results indicate that the proposed method detects power fluctuations in a short time.