A New Method for Fast Power Swing Detection Using the Rate of Change of Energy in the Current Signal

In order to maintain power system stability, modern transmission networks need a high fault detection speed. Therefore, a high level of protection security is required. Distance protection due to its fast fault clearance feature is a commonly used relay for transmission lines. The variation in voltage and current signals during power swing is often the root cause for incorrect operation of distance relay. As a result, the distance relay may initiate a trip command to the breaker to isolate transmission lines unnecessarily. Therefore, power swing blocking (PSB) function is necessary for the distance relay to avoid unwanted tripping of the transmission line. A power swing detection technique is proposed in this paper using the rate of change of energy in the current signal. This method can also detect faults occurring simultaneously with power swings. The practicality of the proposed method is shown in the standard 39-bus test system using the MATLAB and DIgSILENT software. The proposed method is also implemented on a relay and is tested using a relay tester device made by Vebko Amirkabir Co.