It is also necessary to ensure correct voltage throughout
the plant. The PMS ensures correct voltage on any busbars to
which GTGs are connected. The voltage on all other busbars
is controlled by the transformers supplying them. In this case
study, some of the main switchgear and controlgear was
supplied via transformers equipped with OLTCs. The
transformer AVR controls the tap position in order to maintain
the correct busbar voltage. The PMS has no control functions
associated with these transformers.