Efficient coordination of ROCOF and frequency relays for distributed generation protection by using the application region

• Published in: IEEE transactions on power delivery Vol. 21; no. 4; pp. 1878 - 1884
• Main Authors: Vieira, J.C.M., Freitas, W., Wilsun Xu, Morelato, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-10-2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adjustment; Applied sciences; Connection and protection apparatus; Digital relays; Distributed control; Distributed generation; Distributed power generation; Disturbances. Regulation. Protection; dynamic simulation; Electric power distribution; Electric power plants; Electric power systems; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Exact sciences and technology; Frequency; frequency relays; Generators; islanding detection; Manufacturing; Miscellaneous; Optimization; Power networks and lines; Power system relaying; Protection; Protection systems; Protective relaying; rate of change of frequency relays; Security; Synchronous generators; Relay; islanding detection; dynamic simulation; Protective device; Unbalanced conditions; Distributed power generation; Conceptual analysis; Damage prevention; rate of change of frequency relays; Trigger; Loss of mains; Power system protection; Failure detection; Synchronous generators; Delay time; Distributed generation; Electric power production; Dynamic model; frequency relays
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2006.881588

This paper proposes a method for determining the coordination of the rate of change of frequency (ROCOF) and under/overfrequency relays for distributed generation protection considering islanding detection and frequency-tripping requirements. The method is based on the concept of application region, which defines a region in the trigger time versus active power imbalance space where frequency-based relays can be adjusted to satisfy the anti-islanding and frequency-tripping requirements simultaneously. This method can be used to optimally determine the instantaneous and time-delay settings of different frequency-based relays in a unified manner. The application region can be also employed to evaluate how much an existing frequency-based protection scheme violates one of the above-mentioned requirements. In addition, it can be used to set different combinations of frequency-based relays in order to make the distributed generator frequency-based protection system as efficient as possible, since it respects the region that satisfies both requirements