Abstract: This paper introduces modulation techniques to reduce harmonics in Flexible Power Electronic Transformer. The proposed FPET is power electronic based transformer which has enough flexibility to satisfy future needs of power electronic centralized systems. The main feature of the FPET is the independent operation of modules each of which contains one port and connected to a common dc link. Each port can be considered as input or output, because bidirectional power flow is provided. More harmonic component in the input current of FPET has been compared to the similar circuits topologies proposed for multilevel PET. PSM i.e. PHASE SHIFT MODULATION technique will be applied to FPET to control voltage and reduce harmonics. SPWM, SIGMA DELTA MODULATION, and HYSTERESIS BAND CONTROL MODULATION techniques would be used to reduce THD of voltage and current waveforms of FPET

Keywords: DC Source, IGBT, INVERTER, CYCLOCONVERTER, LC-FILTER, MODULATION TECHNIQUES, BI-DIRECTIONAL POWER FLOW, HFIT.