Modelling and sensitivity analyses of equivalent models of low voltage distribution grids with high penetration of distributed generation

This paper addresses the fault current contribution of low voltage (LV) grids with high penetration of distributed generation (DG) to large disturbances in overlaying transmission networks. In order to be able to analyse the impact of active distribution networks (ADNs) within a reasonable computational time, equivalent models need to be developed. Within this paper black box models of LV grids are proposed using methods of nonlinear system identification. The large variety of LV grids with regard to different grid topologies, r/x-ratios and DG penetration levels can be analysed in parameter studies using methods of sensitivity analysis. With the help of the results a limitation of the parameter space shall be achieved in order to reduce the total number of equivalent models that need to be included in future stability studies with strong contribution of ADNs.