Control Strategy for Three-/Four-Wire-Inverter-Based Distributed Generation

Future power distribution requires advanced expandability and flexibility in the integration of distributed energy resources which normally require interfacing units to provide the necessary crossing point to the grid. The core of these interfacing units is power-electronics grid front end, namely, inverters. The inverter is the primary interface that provides not only their principal interfacing control function but also various utility functions. This paper presents the flexible control methodology of inverters as grid front end using an isochronous control function which is used by synchronous generators in conventional power systems to provide load sharing and control.