“Mitigation of current harmonics and unballances using power electronic transformer”

The widespread increase of non-linear loads nowadays, significant amounts of harmonic currents are being injected into power systems. Active power filters (APF) have proved to be an interesting and effective solution to compensate current harmonics and reactive power in power distribution systems. Power electronic transformer (PET) is a new type of transformer, which realizes voltage transformation and power delivery in a power system through power electronic conversion. The proposed PET performs typical functions and has advantages such as power factor correction, voltage regulation, voltage sag and swell elimination, voltage flicker reduction and protection capability in fault situations. In this paper, parallel operation of PET to compensate current harmonics, unbalance currents and reactive power in power distribution systems the same as APF is discussed. In the other hands, synchronous by feeding special loads by PET, this transformer acts as APF. Power quality improvement with power electronic transformer has been verified by the simulation results with MATLAB/SIMULINK.