A New Active Islanding Detection Technique Using Superimposed Power Angle Disturbance of IBDER

Abstract

In this paper, a new active islanding detection technique (AIDT) based on superimposed positive-sequence (p-s) power angle disturbance is proposed. The injection of disturbance signal leads to a superimposed positive-sequence phase angle (SPPA) deviation at the inverter-based distributed energy resource (IBDER) terminal during islanding event. It is found that the variation in SPPA is capable of detecting unintentional islanding conditions. Since the sequence elements of voltage and currents during islanding event are different from that of a pre-islanding event, superimposed elements are derived at the IBDER terminal. Furthermore, the proposed technique is capable of identifying nonislanding events such as voltage sag, three-phase faults, load switching, and capacitor switching. The proposed technique along with the control schemes of IBDER units is developed using real-time digital simulator (RTDS). The performance of the proposed technique is compared with the conventional techniques. The detection time for the proposed method is within the specified range in IEEE Std. 1547, and is around 20 ms.