Frequency Stabilizing Scheme for a Danish Island Grid

This paper describes the development of frequency stabilizing control scheme for a small Danish island of Bornholm. The Bornholm power system is able to transit from interconnected operation with the Nordic power system to isolated islanding operation. During islanding operation the shedding of wind power is necessary to avoid unwanted power oscillations, which lead to uncontrolled oscillations in the power plant control.

Since this might deteriorate power quality including frequency in an island grid, a frequency stabilizing control scheme or strategies using intelligent controller with a battery energy storage system (BESS) has been proposed. The real-time models of distribution grids of Bornholm power system were used to carry out case studies to illustrate the performance of centralized load frequency control as well as coordinated control scheme.

Case study results show that the proposed coordinated control scheme can efficiently help stabilize the frequency after switching to islanding operation.