Comparison of DC-link capacitor types under various grid conditions

Abstract

A DC/AC converter can face negative conditions of power systems such as instability. One of the most crucial necessities of the grid is voltage stability. There are some effects of voltage unbalance for grid-tied DC/AC converters. Grid voltage unbalance causes higher THD values on grid currents than normal grid conditions. THD value of grid current is limited by the IEEE 519-2014 standard. Unstable grid conditions show different results because of the value and type of DC-Link capacitors. In this paper, two types of capacitors are compared with different grid voltage conditions and power factor values for grid-tied 10kVA DC/AC converter. Simulation results are shown and interpreted.