Measurement-Based Verification of Symmetrical Short Circuit Calculations in Transmission Grids

Abstract:
Short circuit calculations are used in operation and planning of transmission grids to ensure a system state within technical limits. This paper discusses a verification of the short circuit level by comparing calculation results to a measurement-based estimation. To this end, the short circuit current is estimated for two different substations in the German transmission grid by using perturbations generated by STATCOMs. The results mostly show that the short circuit levels are consistent between calculations and measurement-based estimations. We can reduce the deviation between the calculated and estimated short circuit level by averaging multiple estimations and choosing appropriate estimation parameters. Remaining high deviations can be attributed to high disturbances superposing the perturbations. However, moderate deviations can occur even in case of low disturbances due to uncertainties in either the calculation or estimation approach, which should be analyzed in future work.