(c) The Power Pool Operating Center is the interconnection of power systems.
(d) The Power System Operating Center monitors the transmission and distribution
centers and power plant operations.
6.2 CONTROL CENTER PROCEDURES. Complex power systems provide reliable electric
service at low cost with the aid of automatic control. These systems simultaneously track the
randomly varying system load, optimize generation to minimize cost, and coordinate the action
of many independent control centers. The primary functions of the control center are to manage
resources, monitor performance and reliability, and adjust control parameters to maintain the
desired quantity and quality of electrical supply.
6.2.1 Power System Parameters. Considerable information regarding the power system is
needed to logically perform the control objectives previously described. The following is a
general listing of the conditions and facts that must be identified.
(a) Position (open or closed) of circuit breakers and switches in the power system.
(b) Power flow, active and reactive, from each generating station, in each tie-line
interconnecting the system with neighboring systems, and at key points in important transmission
(c) Energy (kWH) from generating stations and tie-lines.
(d) Bus voltage at each generating station and essential substations.
(e) System frequency.
(f) System time error, in seconds, based on a particular standard of reference.
(g) Tap position of load-ratio-control transformers or step-voltage regulators at key
points in the transmission system.
(h) Current load on cables and transformers at critical locations in the transmission
The transmission of information between locations is generally accomplished by telemetering.
The transmission mediums are wire circuits, carrier (current) equipment, and radio or microwave.
6.2.2 Control Functions. Centralized equipment, both central (master) and remote, enables
operators to supervise and operate remotely located power system elements (supervisory control
equipment). Examples of the functions or apparatus controlled from central locations by means
of the supervisory control equipment are: