Grid code violation during fault triggered islanding of hybrid micro-grid

The major advantage of a micro-grid is its ability to run in both grid connected and islanded mode of operation providing higher flexibility and reliability. With increasing popularity of micro-grids and their existence becoming more and more prominent in existing power systems, more stringent adherence to frequency and voltage standards are being requested by Distribution Network Operators (DNO´s) in order to maintain proper functionality of the grid. In case of any violations to the aforementioned standards, the distributed generation will have to be disconnected to ensure system security. Fault triggered islanding causes large excursions in system voltage and frequency which may lead to disconnection of DG´s thereby threatening the grid integrity and strength. In this paper a review of IEEE standards and North American Electric Reliability Corporation suggested standards is presented. The use of dynamic voltage restorer as series compensation to ensure successful islanding without violating the standards is proposed. A comprehensive analysis is conducted by time domain simulations using Matlab/Simulink software.