High frequency ground current flow paths in integrated power systems

Integrated electric power systems (IPS) are increasing in number and size. In these systems, a small number of generators supply local load through one or more electronic conversions. In many cases, the load includes one or more devices whose rating is a significant fraction of the generator rating. These systems can either be stand alone or grid connected systems. Equipment grounding and ground path currents have been and continue to be an issue in IPS development. This study presents an in depth analysis of ground path current flows for a generator/rectifier/drive system, which employs a high impedance ground on the generator neutral. The study identifies the generator neutral capacitor and the motor stray capacitance as the primary elements influencing ground path current flow, and provides a parametric study of these parameters and their influence on ground current and line-ground voltage. These results provide information for IPS designers on ground path system design.