A pulse width modulated AC link dynamic voltage restorer

This paper proposes a vector-switching matrix converter able to perform as a dynamic voltage restorer (DVR). The topology connects in series with the distribution feeder and is realized by the cascaded connection of a three-phase capacitor bank, a three-phase single-pole double-throw (SPDT) switch, and a three-phase injection transformer. The entire topology is energy storage-free, and the SPDT switch is pulse width modulated using simple dc duty ratios without the need for a phase locked loop. The paper provides details on the DVR modeling, equivalent circuit, and design considerations. Computer simulations are included to validate the approach.