Single phase voltage sag compensation system based on a modified flyback converter

Nowadays, it is very important to fulfill the energy quality requirements of critical loads. Voltage sags are the most costly kind of disturbance in an industrial or commercial environment. This paper presents an interesting approach to mitigate the effects of these voltage sags, using the nature of the output voltage of PFC converters-using a flyback converter-and also integrating the inverter stage within the main converter, improving efficiency at the cost of having one additional winding in the flyback transformer. The scheme reduces the number of control loops to only one; due to the modification of the output filter of the converter the dynamic response of the converter is improved.