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Continuous injection-based islanding detection of Inverter-Interfaced Distributed Generator (IIDG) has been a general trend. The major issues in previous islanding detection methods are large Non-Detection Zone (NDZ), poor Power Quality (PQ), high implementation cost, and lack of real-time validation. Further, the threshold in most methods is not generic and depends on the system’s rating. Hence, this paper proposes a local voltage and current measurement-based islanding detection method for IIDGs. It utilizes parameters estimated from the fundamental phasors of voltage and current at the Point of Common Coupling (PCC) of IIDG using Space Vector Rotation (SVR) and a controlled self-decaying current injection. The proposed disturbance is injected only after disturbance detection by SVR parameters to mitigate the impact on PQ. Disturbance identification is easy due to the combined PCC voltage and current effects on parameter estimation. Real-Time Digital Simulator (RTDS) and Controller Hardware In the Loop (CHIL) setup-based results from the proposed method have been obtained and compared with previous methods. These results indicate the proposed method’s real-time efficacy (low islanding detection time) with no NDZ and negligible impact on PQ for different islanding events. Also, the proposed method is independent of the microgrid’s rating and reliable for non-islanding events. [ABSTRACT FROM AUTHOR]

System inertia plays a vital role in controlling the angular stability of the system during a disturbance. Due to increased penetration of power electronic interfaced sources, such as Solar Photovoltaic (SPV) source, the overall system inertia reduces and varies depending on their operating conditions. In this paper, an approach for online inertia estimation in the power system network with SPV sources is proposed, using the synchronized measurements from Phasor Measurement Units (PMUs). An equivalent swing equation is used to emulate the network dynamics. A relationship between the inertia constant and the roots of this equation is determined. In order to numerically obtain the roots, the Estimation of Signal Parameter via Rotational Invariance Techniques (ESPRIT) method is first used to find the modes present in the frequency signal. A new formulation is proposed to extract an equivalent mode from all the obtained modes. Also, to avoid phase step error, Rate Of Change Of Frequency (ROCOF) is estimated from the equivalent mode of the frequency signal. Results obtained for the 39 bus New England system for various test cases, using Real-Time Digital Simulator (RTDS), prove the efficacy and superiority of the proposed approach over the existing approaches in the literature. [ABSTRACT FROM AUTHOR]