ABSTRACT
For extended control schemes that rely on a central logic system deciding on corrective action after taking all the available data into account, such an indicator provides little overall benefit. The most common building block within extended control is the switchgear building block, whose purpose is to control a switching device. This chapter shows how the control building block is a subcomponent of the overall distribution substation (MV/LV) or feeder line device building block. This can be very useful when extended control is to be applied to an existing distribution substation the retrofit solution. The chapter looks at whether the automated devices have a local fault passage indicator and whether the devices are under remote control or local control. Protection and fault passage indicator (FPI) both contribute to distribution automation and can be studied together because, although protection relays are usually more complex than FPIs, both employ similar technology.
