Design and Control of a Dynamic Power Quality Compensator for Micro-Grid System

Abstract

This paper presents a design and control of a dynamic voltage restorer as an interface between utility and micro grids (MGs) in order to improve the MGs reliability and stability.  The proposed DVR aims to be used for the compensation of voltage disturbances and mitigation of load current harmonics that MGs may encounter during its interconnection with the utility by using a simple control strategy which employs the Adaptive Noise Canceling (ANC) technique. Further, the fast response and effectiveness of the proposed DVR when installed in a MG is confirmed by simulation using PSCAD/EMTDC software during both normal and abnormal operations of the utility. A set of waveforms for three different parameters, percentage sag, dc-link voltage rating and dc-link capacitor size, is provided that can be used as a setting for the selection of capacitor size for a specific required percentage sag correction. These waveforms is used to minimize the DVR cost by limiting the voltage across the semiconductor switches to low value and decreasing the size of the dc-link capacitor to the value that allows proper operation of the DVR. The dynamic capability of theproposed DVR can be very beneficial for industry and can increase the possibility of employingmore sensitive equipment to be used in MG system. Further, the results can be used by design and maintenance engineers to evaluate the robustness and reliability of a given MG system.