Analysis of Voltage Sensitivity as System Strength in Future Power Grids

Abstract:
There is a growing need for ways to analyse power system strength. This work proposes a new approach that is not based on the short-circuit current contribution or the resulting impedance, but instead exclusively measures the resilience of the voltage vector to changes in the grid. This sensitivity is measured at various nodes in a representative grid as the basis for developing a metric of grid strength. In comparison with the Equivalent Short-Circuit Ratio, it is shown that the results of the new method are significantly more precise for non-synchronous generation as the contribution of grid-forming converters is automatically taken into account.