Finite-Set Model Predictive Control of a Dynamic Voltage Restorer based on a Nine Switch Converter Topology Solid State Transformer

Power quality is a critical concern, especially for voltage sensible equipment whose performance is highly dependent on the stability and reliability of the electrical supply. Disturbances such as voltage sags, swells, harmonics, and interruptions are characterized by deviations in voltage, current, or frequency that can lead to equipment malfunction or failure. Sensitive applications, including medical systems in hospitals, educational institutions, and correctional facilities, are particularly vulnerable, with outages that can result in significant o p erational and economic losses. To mitigate these issues, several solutions based on power electronics have been developed, among which the Dynamic Voltage Restorer (DVR) is widely recognized as one of the most effective and cost-efficient s o lutions. T h e D V R i s a power electronics-based device designed to detect and compensate for voltage sags in real time. This paper presents a dynamic voltage restorer, based on a Nine-Switch Converter Solid State Transformer (NSC-SST) configuration. Results under voltage-sag operation have been obtained using real-time simulation based on a hardware in the loop (HIL) control planform. These results showed that the proposed NSC-SST DVR presents several advantages such as: simple topology when compared with classical SST based on an arrangement of two-level voltage source converters, capable to operate under voltage-sag condition either with classical oriented control or Finite-Set Model Predictive Control scheme.