System Protection Schemes in Eastern Denmark

The Ph.D. project investigates different aspects of voltage stability in the power system of Eastern Denmark taking into account the large amount of wind power. In the project, a simple System Protection Scheme (SPS) against voltage instability in Eastern Denmark is developed. Phasor Measurement Units placed at strategic points are evaluated as an efficient tool for power system monitoring of important 400 kV and 132 kV transmission corridors in Eastern Denmark. Real-time phasor measurements are utilized for tracking power system dynamics during a number of severe power system disturbances that are characteristic for the Eastern Danish power system, such as wind farm rejection, cascading line outages and power oscillations. E.g. Nordic inter-area oscillation modes and damping were easily detected from phasor data during the outage of the 400 kV tie-line between Eastern Denmark and Sweden. One case study demonstrates that the recorded power system response is consistent with the simulation results. The PMU units could enable the system operator to detect catastrophic events in due time and issue remedial orders in the power system.