Effects of Component Failures in Drive Inverters during Parallel Operating on an Open Industrial DC Grid

An open industrial DC grid for energy supply has many benefits. Also new challenges arise by coupling the DC link capacitors of all devices, e.g. inverters. This paper presents the effects of component failures causing short circuit faults in combination with electrically coupled and charged DC link capacitors. Resulting energy flows are shown, which arise in the DC grid in case of faults. In addition, measurements of short circuit tests and two solutions are shown, which enable the safe and simple operation of an open industrial DC grid.