Approximation of Current Contribution by Converters with DC Fault Ride-Through Capability for Short Circuit Current Calculation of DC Distribution Grids

Abstract

This paper presents a novel model including an approximation function to approximate the DC short circuit current contribution by converters with DC fault ride-through capability. The intended field of application of this model is a fast algebraic short circuit current calculation for DC distribution grid planning. In a first step, converter topologies with DC fault ride-through capability and the current contribution of these converter topologies are presented. Afterwards, based on preliminary investigations an approximation function to approximate the current contribution is derived. Finally, the derived model is validated by comparing the current contributions of the model with results of detailed transient simulations.