Influence of voltage sags on dynamic voltage behavior with massive inverter-based loads

The self-disconnection of photovoltaics (PVs) due to voltage sags can make the voltage sags more severe, because the sudden loss of PVs at the voltage sags increases the apparent load, which consists of the net loads and PVs. The voltage sags cause the self-disconnection of loads as well as PVs. Because inverter-based loads are easily disconnected from the power system, the self-disconnection of such loads causes a significant rise in post-disturbance voltage, which is a major concern in Japan. Therefore, the influence of the self-disconnection of massive inverter-based loads on dynamic voltage behavior was clarified ahead of examining the influence of the self-disconnection of massive PVs. A sensitivity analysis of dynamic voltage behavior on induction motors as well as the self-disconnection of loads through time-domain simulation using real system data is presented. The anticipated dynamic voltage behavior with massive inverter-based loads is also discussed.