PASSIVE Anti-Islanding Methods

Passive Anti-Islanding Methods monitors the variation in system parameters such as frequency, voltage and current on the DG side at the Point of Common Coupling (PCC). In case of islanding, these parameters display variations which have been used to detect islanding. The methodology of choosing the limits of variation of these methods mainly depend on the IEEE standard 1547 [18] which is shown in table 1.
\begin{equation} {P=\ P}_{\text{DG}}-\ P_{\text{LOAD}}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (3)\nonumber \\ \end{equation}
\({\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ Q=Q}_{\text{DG}}-\ Q_{\text{LOAD}}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (4)\)
Figure 5 presents a single line diagram of a grid-connected DG source. The real power (ΔP) and reactive power (ΔQ) delivered are represented by Eqs (3 and 4) respectively.
\(P_{\text{DG}}\ \)and \(Q_{\text{DG}}\ \)are the real and reactive power delivered by the DG source respectively. Similarly, Pload and Qload are the real and reactive power absorbed by the load.
Table 1 of IEEE 1547 standard for IDM