A Supervisory Control and Data Acquisition (SCADA) system is used in Power plants ( Thermal, Hydro, Nuclear and Gas Plans) for implementing control interlocks for electrical equipments in the switch yard and data acquisition functions for switch yard and electrical auxiliary systems in the power plant. SCADA system is both Hardware and Software.
SCADA System in Power Plants:
Electrical SCADA system in power plant is located in two control locations; Switch yard Control Room, and respective Main Control Room.
In Switch yard Control Room SCADA system is to monitor and control of high voltage transmission lines (400kV/220kV) from switch yard control room through Man Machine Interface (MMI) of the electrical SCADA system.
Man machine Interface (MMI)is a Video Display Units which display diagrams, bar charts,analog trends, tabular designs etc to display parameters such as voltages, currents, etc and annunciations.
The control of main transformers in the power plant such as
Generation transformer used for step up the generation voltage from the generator and Station transformer used for deriving the power during plant star up and control of circuit breaker in plant is done through the Man Machine Interface.
Important auxiliaries like Battery system, UPS systems, Diesel Generators are also monitored and important alarm annunciations and window annunciations are provided at the Main Control Room.
Functions Of SCADA system:
- Periodic Monitoring and logging of data such as frequency, voltage, current, etc. from electrical auxiliaries
- Classification of alarms in order of priority and providing annunciations at the time of events
- Displaying status of isolators, breakers and single line diagram of various systems in switch yard
- Controlling circuit breakers and Isolators in switch yard .