Bifurcation study of three-phase inverter system with interacting loads

Plenty of distributed generation (DG) units directly export DC power such as the PV arrays. As a commercial interface, three-phase voltage-source inverters (VSIs) are commonly equipped for the power conversion from the DC power sources to the AC utility. In a practical DG system, the grid-connected loads are full of dynamics at the point of common connection (PCC). Thus, grid-connected loads inevitably have mutual interaction with VSI at PCC, which may have an impact on the stability and deteriorate the regulation capability of VSI. In this paper, the oscillatory behavior of single three-phase VSI is studied in the presence of resistive loads. The corresponding oscillation boundaries of the system are numerically collected for various circuit conditions with respect to the emergence of a low-frequency oscillation as a Hopf-type phenomenon.