Prospective Single and Multi-Phase Short-Circuit Current Levels in the Dutch Transmission, Sub-Transmission and Distribution Grids

摘要

As elsewhere in the world, also in the Netherlands utilities face an increase in the actual and futureshort-circuit current levels at all voltages. This development is provoked by the required increase intransmission capacity as well as the concentration of power generation capacity. Large electricityproduction sites are moved to peripheral locations, thus overstressing the local transmission networkswith respect to both the transmission capacity and the short-circuit power withstand capability.Dispersed power generation facilities, like windmills and co-generation plants for greenhouses, tend toappear in the same (optimal) neighborhoods, thus overstressing the local distribution and subtransmissionnetworks.In the paper the development of short-circuit currents in the Dutch 400 kV-grid is illustrated. Inaddition, some particular aspects of the short-circuit currents will be addressed: three-phase and singlephase fault currents, DC-time constants, peak values, contributions from transformers and distributedgenerators. Practical calculation guidelines on the actual short-circuit contribution from generators willbe given.An example of design of a 400 kV station extension, emphasizing short-circuit current considerationsis evaluated. National and international trends are addressed.More severe specifications of substation equipment lead to adapted designs and adequate testingprocedures. Examples from testing of the consequences of short-circuit currents and fault arcs of 80kA and above are highlighted.