Transformerless Dynamic Voltage Restorer for Medium Voltage Applications

Power quality is an important issue due to its impact on electricity suppliers, equipment manufactures and customers. In this paper a predictive voltage control scheme for the effective control of transformer less dynamic voltage restorer (TDVR) is discussed. This control scheme employs the discrete model of a voltage source inverter and a filter for the generation of the switching strategy of inverter switches. Predictive voltage control algorithm based TDVR utilizes the reference voltage effectively. And thus maintains sinusoidal load voltages during various voltage disturbances as well as load conditions. Moreover, this scheme does not require any linear controller or modulation technique.