A smart fault detection and localization strategy of modular multi-level converters for HVDC networks

This paper presents a new fault detection and localization strategy for Modular multilevel converters (MMC). The proposed fault detection technique depends on the estimation of the sub-module capacitor voltages using the RLS algorithm without the need of extra sensors or special power circuits. The dynamic performance of the proposed strategy is investigated using hardware in the loop (HIL) based on an OPAL-RT real time digital simulator and a cRIO FPGA controller. The real-time simulation results clearly show the robustness of the proposed technique in terms of accuracy and time which significantly enhances the reliability of the MMC.