Single-phase AC-AC converter operating as a dynamic voltage restorer (DVR)

This paper presents a single-phase AC-AC matrix converter which is able to compensate voltage harmonics and voltage regulation at critical loads terminals. The converter is composed with the minimum number of switching devices and is controlled using a non-linear law based on passivity achieving a high reliability and robustness during transient and steady state operation condition. The proposed scheme has the advantage that energy storage devices are not required. The converter is connected between the AC mains and the load through a series transformer. A DSP and a FPGA are used to program the passivity-based controller and to determine the state of the switches respectively. In this case, the converter is able to compensate up to 25% voltage sags and 50% voltage swells and to eliminate up to the fifteenth harmonic component. The tested system presents a fast time response and the stabilization time of the load voltage is less than 1ms. Analysis and modeling as well as simulation and experimental results of a 5kVA, 127V, 60Hz experimental setup are analyzed and presented.