Resonances and Oscillations in DC Grids

Inhalt:
A trend has been emerging in the field of industrial automation: direct current (DC) is making a comeback. This is due to the desire for greater energy efficiency and flexible, intelligent energy distribution. However, DC can still exhibit alternating current (AC) components from pulsating loads on an industrial grid, which may excite resonances. This work derives an equivalent circuit model for the grid and verifies it using a motor test bench. Design considerations for the DC link capacitance are presented to enable the integration into a decentralized drive.