Modeling of switching power interfaces for smart-grid stability studies

Stability analysis of power systems dominated by power electronics devices is a challenge for the future. This paper focuses in the analysis based on impedance representation of a three phases inverter operating as voltage source. Therefore, two small signal input impedance modeling methods are described, the first is the linearized state space model methodology and the second is based on the assumption of no energy storage at the AC and DC side of the inverter. For both methods a comparative evaluation with the impedance obtained was realized by the application of a voltage perturbation to the DC side. The obtained results show that the proposed method can be employed in the studies of stability of power electronic systems.