SCADA (Supervisory Control and Data Acquisition)

Supervisory Control and Data Acquisition

Supervisory control and Data Acquisition is an industrial control system that is used in many modern industries like energy, manufacturing power, water transportation, etc. SCADA software receives the info form (PLCs) or remote terminal units (RTUs) which in turn receive their info from the sensors or inputted value which we have given manually.

SCADA refers to supervisory control and Data Acquisition. It is used to monitor and control a power plant. It is used to collect data from instruments and sensors located at remote sites and do transmit data at a central site for either monitoring or control. It is an industrial control system that is used in many modern industries like energy, manufacturing power, water transportation, etc.

SCADA is a widely distributed computerized system and is primarily used to remotely control and monitor the condition of filed-based assets from a central location. field-based assets include usually pump stations, valves, treatment plants, tanks, etc.

Objectives of Supervisory Control and Data Acquisition

• Monitoring: Continuous monitoring of parameters of voltage, current, etc.
• Measurement: Measurement of variables for processing.
• Data Acquisition: Frequent acquisition of data from RTUs and Data Loggers/phasor Data concentrators (PDC).
• Data communication: Transmission and receiving of large amounts of data from the field to control centers.
• Control: Online real-time control for closed-loop and open-loop processes.
• Automation: Automatic tasks of switching transmission lines, CBs, etc.

Need for Supervisory Control and Data Acquisition System

1. Monitor the system
2. Control the system and check the required performance is always achieved.
3. Reduce operational staffing levels by using automation or an operating system.
4. Store data of all operations for further use
5. Provide info on performance and use to improve energy management
6. Improve efficiency operation, minimize routine checks or remote site
7. Reduce power consumption during pumping operation(also provides security)
8. Provide an alarm system, use to detect the fault from the central point and overcome the fault in the fast mode without damaging the other equipment.
9. Visualization of all operations by graphical representation.

Major components of the Supervisory Control and Data Acquisition system

The major components of Supervisory Control and Data Acquisition are:

• Sensors: it is used to measure and collect data from various location remotely. It measures both input and output. Digital sensors measure discrete inputs whereas Analog sensors detect continuous change at the site. Sensors are used for checking current level, temp, power, and fault protection.
• Conversion unit (PLC)or RTU(Remote terminal unit): PLC (programmable logic controller) are connected to sensors and convert information received into digital information and transmit it to the master unit. PLC stands for data collection, receiving critical information about the flow and input within the system.

• Master terminal unit (MTU): It is the supervisory computer system. This unit serves as the SCADA system control processor. It provides a human interface and automatically regulates the system based on information received from the sensor.
• Human interface interface (HMI): HMI presents the information required for the interaction between the user of the SCADA and the master terminal unit.

Modes of Operation

• SCADA system includes signal hardware (input and output), controller, networks, user interface(HMI), communications equipment, and software.
• A large number of remote terminal units(or RTUs) /PLCs collecting field data connected back to a master station via a communication system.
• The master station displays the acquired data and also allows the operator to perform remote control tasks.
• The accurate and timely data(normally real-time) allows for optimization of the operation of the plant and process.

Functions of Supervisory Control and Data Acquisition

• Data Acquisition
• Information Display
• Supervisory control
• Alarm processing
• Information Storage and Reports
• The Sequence of Event Acquisition
• Data calculation
• Special RTU processing/control

Working Principle of Supervisory Control and Data Acquisition

The microprocessors from the PLCs collect data from the field devices and transfer it to the SCADA server software where it is recorded and analyzed, then displayed by the HMI.

Supervisory control and Data Acquisition in power distribution

Power system deals with power generation,transmission and distribution sectors,monitoring and controlling is main aspect in all these areas. Thus the implementation of SCADA in power system improves the overall efficiency of the system for optimizing,supervising and control the generation and transmission system. SCADA function in the power system network provide greater system reliability and stability for integrated grid operation.

SCADA in power system in which it collects the entire data from many electrical substation. RTU/PLC in substation component and transmits that data to centralized PC based and SCADA system. SCADA allows to find exact location of fault therefore without waiting for call form customer, SCADA gives an alarm system to the operators for identifying the fault and preventing before starts interrupting the whole distribution network. SCADA automatically controls isolate switches and circuit breaker for violating physical parameters limits thereby daily inspection parameter are performed without a line worker.

Function of Supervisory control and Data Acquisition in power Distribution

• It helps to improve efficiency and power factor
• It helps to Limit peak power demand
• Helps to monitor and control electrical parameters in normal and abnormal condition
• Alarming system, rings alarm to operator when fault occur
• It gives historic and viewing data form remote location
• It gives quick response if there is service interruption

Advantages of Supervisory control and Data Acquisition system

• It helps to monitor the system
• It helps to control the system and to check the required performance is always achieved.
• It helps to reduce the operational staffing level by using automation or operation system by central location
• It store data of all operation for further use
• Provide information of performance and use to improve energy management system
• Helps to improve efficiency,operation,minimizing routine check or remote site.
• Reduce power consumption and also provide security to the system
• Provide alarm system use to diagnosed the fault from central point and overcome the fault in fast mode without damage the other equipment’s by using RMS technology.
• visualization of all operation by graphical representation.

References

• https://www.techtarget.com/whatis/definition/SCADA-supervisory-control-and-data-acquisition\
• https://inductiveautomation.com/resources/article/what-is-scada
• https://www.spiceworks.com/tech/tech-general/articles/what-is-supervisory-control-and-data-acquisition-scada/
• https://www.sangfor.com/glossary/cloud-and-infrastructure/what-is-supervisory-control-and-data-acquisition
• https://www.dpstele.com/scada/how-systems-work.php