Investigation on operating behavior of selected DC-provided components of a substation at depth discharge

Abstract

In case of a blackout, substations have a central meaning for grid rebuilding, in addition to line-assets and power stations. The time within substations can be remote controlled and operated without external power supply is called “autonomous-time”. It is rough defined by the capacity of the GSV-equipment (number of cells, condition, age) and the load (load- resp. consumption-behavior) of the DC-supplied components.In case of a grid restoration, which lasts longer than the autonomy-time of the substation, the battery gets depth discharged. The aim of this investigation is, to find out, how long the DC-supplied components will still operate in that case, whether and when it will come to dangerous or oscillations between batteries and DC-consumers and to see, if the DC-consumers will still operate in case of an recurring-voltage. To sum up, it can be said that, to protect the devices it is highly recommended that the operation of the DC-provided components must be avoided in case of depth discharge of the battery. A manual shut down of the battery is suggested before the expiration of the autonomous time.