Identification of Required Converter Models for a Simplified Short Circuit Current Calculation of DC Distribution Grids

Abstract

DC distribution grids are subject of current research. One important aspect is a simplified short circuit current calculation for designing and selecting grid equipment. For a simplified short circuit current calculation method as less as possible models are desired. Therefore, this paper investigates the behavior of different converter topologies in case of a DC short circuit by conducting transient simulations. Based on the investigations the minimal acceptable number of required models for approximating the short circuit current contribution of converters is identified. As a result the minimal acceptable number of standard models of converters for a simplified short circuit current calculation is five. With these five standard models the short circuit current contribution of all converter topologies can be approximated accurately.