Fig. 14 gives a very basic overview of a PMS. It shows the
connections to the electrical distribution system through
communication networks to intelligent devices, and hard-wired
digital and analog signals. The operator workstations are also
shown connected to the communication network. The
redundant programmable logic controllers (PLCs) required for
power management functions are shown including their
interface to the governors and AVRs. This interface shows the
use of incremental set point changes, one of the basic
principles of Robust Control.