Basic Of SCADA:
What is SCADA?
In process industry, many enterprises are going for manufacturing resource planning (MRP) or enterprise resource planning (ERP) system in the business for
1. Elimination of duplicate data system throughout the enterprise.
2. To provide preventative and cost effective maintenance scheduling.
3. To provide more accurate and timely data to support business process.
To achieve above objectives the supervisory control system is designed on the standard level and to the proprietary level also. This is called as the SCADA. The SCADA stands for Supervisory Control And Data Acquisition.
- As the name indicates, it is not full control system but rather it focus on the supervisory level.
- At actual, it is a software package i.e. positioned on the top of the hardware to which it is interfaced. In general this hardware is either the programmable logic controller, programmable automation controller or other commercial hardware modules.
- Thus the SCADA is a central control system that monitors and controls complete site or system.
- For example a PLC may control the flow of cooling water through part of industrial process, but SCADA system may allow operator to change the control set point for low and will allow alarm conditions such as loss of flow of high temperature to be recorded and displays.
|Image Source: Wikipedia SCADA Interface|
What are the functions of SCADA systems?The supervisory control and data acquisition systems are useful multipurpose utility management and control tools.
The modern SCADA system may incorporate the following functions
- System monitoring
- System control
- System management
- Demand side management
1. System monitoring:
- All SCADA system provides real time monitoring of utility system status.
- Most of the SCADA systems have sufficient accuracy for metering.
- It includes the detection of local and remote signal status, and the status of sequence of events.
2. System control:
- These controls include corrective control, preventive control and emergency control.
- The corrective control activates when the system parameters crosses the set point values towards upper or lower levels.
- The preventive control is actually sort of protection control which does not allow to accumulate the unexpected status of the system parameters to lead to worst levels.
- The emergency control is the type of system control in which the normal operation of the system is suspended and the alert signals are generated to draw the attention of the operator or it is accomplished automatically.
3. System management:
- The SCADA system collects real time data for future use and analysis.
- This data is then used for off-line system analysis of losses, load conditions and fault frequencies.
- The recorded sequence of events data may be analyzed quickly to identify the origin of electrical faults.
4. Demand-side management:
- This function is applicable for energy management and electrical supply scheduling.
- Using the remote and automatic control of circuit breakers, SCADA system can be used in load management to reduce peak hours of power consumptions.
Explain the benefits of the SCADA.
- SCADA system can help industries to save time and money.
- It can eliminate the need of frequent visits to site for personal inspection, adjustments and data collection.
- The SCADA software enables to monitor the operation in real time.
- It can modify the present system in flexible way.
- It can auto generate the reports and troubleshooting tasks.
- It improves the efficiency of the set up and reduces the operational costs.
Which are the applications of the SCADA?
- Electrical power generation, transmission and distribution: Here the electric utilities use SCADA system to detect current flow and line voltage, to monitor the operation of the circuit breakers.
- Water and Sewage: State and Municipal water utilities use SCADA to monitor and regulate water flow, reservoir levels, pipe pressure and other factors.
- Buildings, facilities and environments: Facility managers use SCADA to control refrigeration units, lighting, entry and parking systems.
- Manufacturing industry: SCADA systems manage parts inventories, regulate industrial automation and robots.
- Traffic signals: SCADA regulates traffic lights, control traffic flow and detects out-of-order signals.