New Islanding Detection Method for Inverter-Based Distributed Generation Considering Its Switching Frequency

• Published in: IEEE transactions on industry applications Vol. 46; no. 5; pp. 2089 - 2098
• Main Authors: Lee, Soo-Hyoung, Park, Jung-Wook
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Delay; Distributed control; Distributed generation (DG); Electric power distribution; Electric power generation; Electric power systems; Electric utilities; Electricity distribution; inductance concentration bus; Inverters; islanding detection; load concentration bus; Methods; Power quality; Power system harmonics; Power system reliability; Power system stability; Power systems; pulsewidth modulation (PWM) inverter; Reactive power; Safety; Stability; Switching; Switching frequency
• DOI: 10.1109/TIA.2010.2049727
• ISSN: 0093-9994

Islanding detection is one of the most important issues for the distributed generation (DG) systems connected to an electric power grid. The conventional passive islanding detection methods inherently have a nondetection zone (NDZ), and active islanding detection methods might cause problems with safety, reliability, stability, and power quality on a power system. This paper proposes a passive islanding detection method with the zero NDZ property by considering the switching frequency from an inverter of the DG system. Moreover, the proposed method does not cause any negative effects in the aforementioned problems because it avoids applying the intended changes such as variations of reactive power and/or harmonics, which are required in the active islanding detection methods. Several case studies are carried out to verify that the proposed method can detect the islanding operation within 20 ms, which is less than 150 ms required in a recloser as the shortest mechanical reclosing (delay) time. Moreover, this value satisfies the requirement of 2 s given in IEEE Std. 1547.