A new power swing detection method based on chaos theory

The power swing blocking function is a very important element for distance relays to prevent unwanted tripping of transmission lines. In this paper, a new method is proposed for blocking of distance relay when a power swing occurs. In proposed method, chaos technique is used to detect the power swing and discrimination the faults occurring simultaneously with a power swing. The proposed algorithm detects the power swing using logistic map and blocks the relay. Also, the relay will be unblocked by the proposed algorithm when a permanent fault occurs simultaneously with the power swing. To evaluate the performance of the proposed algorithm, different types of power swings and simultaneous faults are simulated in DigSilent software. Then, the achieved data from the simulations are used in the Matlab environment to apply chaos theory for distinguishing between power swing and faults. The proposed method is also implemented on a real-time relay and has been tested by using a tester device. The results achieved by various case studies demonstrate the pertinence of the proposed method.