Arm energy balancing techniques for modular multilevel converter for both equal and unequal frequencies operations

10.18453/rosdok_id00004850 Sah, Gyanendra Kumar Gyanendra Kumar Sah http://d-nb.info/gnd/1370530102 Arm energy balancing techniques for modular multilevel converter for both equal and unequal frequencies operations Universität Rostock 2023 620 Engineering & allied operations 621.3 Electrical Engineering, Electronics 2023 en https://purl.uni-rostock.de/rosdok/id00004850 urn:nbn:de:gbv:28-rosdok_id00004850-8 This work investigates and presents many possible degrees of freedom and arm energies regulation techniques of MMC for both equal and unequal single-phase and three-phase system frequency operations. Only four average arm energy controllers are found to be possible, which do not inject harmonics into the source and load currents. Of these four methods, only two are stable for equal frequency operations. A new seven-arm direct AC-AC MMC topology is proposed to increase the converter's power density if the source does not allow reactive power flow for equal frequency operation of MMC.