A Single Phase Dynamic Voltage Restorer (DVR) With Direct AC-AC Converter Using dq Transform to Mitigate Voltage Sag

Voltage sag is a phenomenon of a short time voltage reduction from the nominal value which often occurs in the industrial’s electricity. Certainly, it causes negative impact on industrial production. The solution to this problem is by installing AC-AC converter that is modified into Dynamic Voltage Restorer (DVR). AC-AC converter is used in this design to minimize battery usage and to reduce harmonic components. The method used is transformation of direct-quadrature (dq) synchronous reference frame for single phase systems. It transforms AC variables, from stationary frame to the dq rotating frame into DC variables. The circuit model and the result in Power SIM simulation where the AC-AC converter output voltage is controlled has been described. DVR in this paper is capable to mitigate line voltage up to the remaining 25%.