Impedance-Based Stability Analysis of a Single-Phase Community Microgrid in Islanded Mode

When a microgrid operates in islanded mode, stability becomes an issue, especially as the system configuration changes over time. This calls for a systematic modeling approach to study the stability of microgrid in islanded mode. In this paper, the impedance-based stability analysis is applied to assess the stability of a single-phase community microgrid in islanded mode. A new method of impedance modeling of single-phase inverter using the state-space model based approach is proposed. This method is successfully adopted in the case study to assess the microgrid stability under different conditions. The case study results suggest the need for more robust DER interface design and DER control to maintain the microgrid stability.