On the Reliability of Static Load Models for the Modeling of Active Distribution Networks under Steady-State Conditions

Robust and well-established distribution network (DN) equivalent models have been used by system operators. Nevertheless, the advent of distributed energy resources (DERs) has changed the nature and the characteristics of the DNs triggering the need for updating the existing models. This study deals with the reliability of the exponential and polynomial static load models on active DN (ADN) modeling under steady-state conditions. The accuracy of the examined models is evaluated under specific load types and DERs penetration level. The conducted analysis reveals the high impact of the DER penetration level on the model accuracy and its parameters. Results indicate that the ZIP model presents higher accuracy compared to the exponential. However, both models fail to accurately capture the steady-state behavior of ADNs in case frequency and voltage controls are applied to the DER units.