Fault Location in Hybrid AC/DC Transmission Grids Containing DERs and HVDC Lines

This paper introduces a new fault location method for hybrid AC/DC complex transmission grids containing Distributed Energy Resources (DERs) and Modular Multilevel Converter-High Voltage Direct Current (HVDC) lines. Digital Fault Recorders (DFR) in the DC grid cannot observe faults occurring in the AC network and vice-versa. The proposed algorithm accurately locates faults irrespective of their location using a subset of DFRs selected by a K-means clustering method. The algorithm is tested using an AC/DC complex transmission network formed by merging the modified IEEE 39 bus transmission system and the CIGRE B4 DC grid test systems under several fault conditions using EMTP-RV and MATLAB as simulation tools.