Designing of a FCM Multilevel Interlinking Converter for Medium Voltage Hybrid Microgrids

This paper presents an improved Flying Capacitor based multilevel converter to link ac and dc subgrids of a hybrid Medium Voltage )MV ( microgrid. Increase in the number of output voltage levels with lower size of filters, increase in the number of combinations to obtain a desired voltage level (redundancy), lower voltage and power rating of components and natural self-balancing of flying capacitors and dc link voltage compared to other conventional converters are the main properties of proposed interlinking converter. The proposed multilevel converter can decrease the limitations on power transfer between ac and dc subgrids, which can significantly complicate the power management and control of hybrid systems. The interlinking converter plays both inverter-based and rectifier-based roles in hybrid system, depending on the power transfer direction. Multilevel based interlinking converters can improve the power quality of hybrid system especially during islanded modes. Furthermore, a modified control strategy has been presented for the interlinking converter. The proposed structure is simulated using PSCAD/EMTDC software and simulation results are presented to validate the effectiveness and advantages of the proposed configuration