Analysis and Comparison of Various Islanding Detection Schemes for DC Microgrids

Islanding detection is a critical issue in the case of AC and DC microgrids (MGs). If the islanding detection technique fails, it may lead to instability in the system. This can affect the load side devices as well as consumers. Many methods have been proposed to detect islanding on AC MGs. Nowadays, the researchers focus on DC MGs islanding detection schemes (IDSs) as the number of converters in DC MGs is reduced significantly. This also leads to reduce total conversion losses to achieve improved efficiency. A current injection-based active islanding detection scheme (IDS) is proposed to detect islanding in DC MGs. This paper compares three passive IDSs, namely under/over voltage (UOV), change in impedance (CII), and rate of change of power (ROCOP) based passive IDSs with the proposed current injection-based active IDS. The performance of these techniques is compared in terms of detection time and the effectiveness during different non-islanding cases. The performance and effectiveness of the proposed IDSs are verified and compared with the help of hardware set up and dSPACE DS1104 controller.