The expansion of electrical power systems by new power stations and new lines (overhead transmission lines and cable circuits) results in an increase of short-circuit currents due to an increase in sources feeding the short-circuit and due to a reduction of system impedance. The improvement of existing installations and the replacement of equipment are necessary, in case the permissible short-circuit current will be exceeded. Measures to limit the short-circuit currents can also be realised which might be more economic than the replacement of equipment and installations. Different measures have to be taken into account such as measures affecting the whole system (higher voltage level), measures concerning installations and substations (separate operation of busbars) and measures related to equipment (Ip-limiter).

Inspec keywords: power stations; power overhead lines; short-circuit currents; power cables; power system protection

Other keywords: electrical power systems; short-circuit current limitation; substations; cable circuits; power stations; overhead transmission lines

Subjects: Power system protection