WHAT IS SCADA AND ITS NEED:

SUPERVISORY CONTROL AND DATA ACQUISITION –we more frequently call it as SCADA. As the name implies SCADA system supervises, acquires and control data received from a distant data source from the control center. SCADA system is located in the control center and is operated in the scanning mode, communicating between the CONTROL CENTER and the REMOTE STATION by means of two-way communication channels. Such a supervisory control and data acquisition system is intended to facilitate the work of operator by acquiring and compiling information as well as locating, identifying and reporting faults. On the basis of information received, the operator makes necessary decisions via the control system he can the perform different control operations in power stations or influence the processing of 

information acquired. The main task of a modern day power system is to ensure quality and reliable power at an economic rate. Hence the system is to be updated at a very fast rate (real time mode/management), which helps to control the complex system effectively without any loss of time.

FUNCTIONS OF SCADA:

 DATA ACQUSITION- Furnishes status information & measurands data to operator

 CONTROL - Allows the operator to control the devices e.g. ckt breakers ,Xmer, tap changer etc from a remote centralised location .

DATA PROCESSING - Includes data quality & integrity check , limit check , analog value processing etc.

TAGGING - Operator identifies any specific device & subjects to specific operating restrictions to prevent from unauthorized operation.

ALARMS - Alerts the operator of unplanned events & undesirable operating conditions in the order their severity & criticality.

LOGGING- Logs all operator entries, alarms &selected entries.

TRENDING- Plots measurements on selected scale to give information on the trends e.g. one minute, one hour etc.

HISTORICAL REPORTING - To save & analyze the historical data for reporting, typically for a period of 2 or more years & to archive.

FUNCTIONAL UNITS OF SCADA:

 1.Data collection equipment.

2.Data transmission / telemetric equipment.

3. Remote terminal unit.

4. Data loggers.

5. Data presentation equipments.