Application of Trans-ZSI DVR for Power Quality Enhancement in Grid-Integrated PV Systems

This paper proposes an advanced Dynamic Voltage Restorer (DVR) that uses a Trans-Z-Source Inverter (TransZSI) topology and is powered by a solar PV source to enhance power quality in off-grid PV systems. By applying the proper corrective voltage at the Point of Common Coupling (PCC), the DVR, a voltage compensation device, corrects voltage disturbances. Because of its inherent buck-boost capability, higher voltage gain, reduced passive components, and lower voltage stress across components, the TransZSI is chosen over traditional Voltage Source Inverters (VSI). A hybrid control strategy—Unit Vector Template combined with Maximum Constant Boost Control (UVT-MCBC)—is used to improve the harmonic suppression in the injected voltage and guarantee accurate voltage disturbance compensation. Under a variety of grid disturbances, such as voltage swell, interruptions, deep sags, and shallow sags with harmonic distortion, the performance of the suggested TransZSI-DVR employing UVT-MCBC has been assessed. Comparative simulation studies verify that, in comparison to conventional ZSI-DVR and VSI-DVR systems, the suggested TransZSI-DVR provides superior voltage regulation and power quality improvement. In addition to enhancing the PV system's overall output quality and preserving voltage integrity at the PCC, the integrated TransZSI-DVR efficiently reduces voltage sags, swells, and interruptions.