Comparison of Dynamic Simulations and Steady-State Calculations of Fault Currents in Distribution Grids with high DG Penetration

Abstract:
The research project “Protection for Future Distribution Systems” (ProFuDiS) deals with the impact of distributed generation (DG) on the protection systems of distribution grids. Several cases have been identified that have a potentially negative effect on the correct tripping behaviour of protection devices. To quantify these effects with regard to network topologies, DG parameterization, location of the DG etc. large parameter studies need to be performed using a steady-state short circuit calculation method with a low computational time. In order to validate the results of the steady-state calculation, test systems have been analysed using dynamic simulation with high computational effort for particular worst case scenarios of challenging grid topologies compromising the correct tripping of protection devices. The results of the comparison with regard to fault currents and residual voltages are presented for two case studies dealing with the effect of blinding in networks with high DG penetration. Furthermore, a comparison of the computational results with measurements from laboratory tests is presented for selected setups.