Design of an islanding detection circuit for dispersed generators with self-commutated static power converters

In this paper, an islanding detection circuit designed for dispersed generators with self-commutated static power converters is proposed. This circuit is suggested based on the monitoring of the magnitude and sign change in the ratio of the frequency deviation to the load variation. To facilitate the detection process, an asymmetrical circuit for generating the output power deviation is developed. The proposed method has been tested under various scenarios in order to examine the detection performance. It is found that the proposed method effectively detects the islanding event while different amount of power mismatch is considered. The test results help verify the effectiveness and feasibility of the proposed approach