Use of sensitivity factors to support congestion zoning on flexibility markets

Distribution system operators face more and more issues due the rapid spread of intermittent renewable energy sources on distribution grids. The most significant of these issues on the Hungarian distribution grids is the excess of voltage limits. In this paper sensitivity factors are defined to connect network voltage constraints and market-based flexibility products. A simplified network model is created based on the characteristics of Hungarian distribution grids for both medium voltage and low voltage investigations. Sensitivity factors for voltage control are calculated with both active and reactive power flows. Correlations between the effects of interventions on both different branches and voltage levels are examined. It is demonstrated that the effect of active and reactive power flows is primarily defined by the impedances of the lines. It is also shown that congestion zones can be created both per branches and voltage levels on radial networks, as the cross effects are insignificant.