SCADA carries out the supervision, protection and automatic control of various equipment in distribution systems with the use of intelligent electronic devices (or RTU). Restores the power service during the fault condition and also maintains the desired operating conditions:
Functions of SCADA:
Most products allow actions to be triggered automatically by events. A scripting language provided by the SCADA products allows these actions to be defined. In general, you can load a particular screen, send an email, run an application or user-defined script and write to the RTDB.
The concept of recipes is compatible, so a particular configuration of the system can be saved to a file and then reloaded at a later date.
2. Access Control:
Users are assigned to groups, which have read/write access privileges defined for the process parameters in the system and, often, also for product-specific functionalities.
Man-Machine Interface(MMI) support multiple screens, which can contain combinations of synoptic diagrams and text.
On-line configuration and customization of the MMI are possible for users with the appropriate privileges. Links can be created between display pages to navigate from one view to another.
Most of the SCADA products that were evaluated decompose the process into “atomic” parameters (for example, a feed stream, its maximum value, its on / off status, etc.) to which a label name is associated. Label names used to link graphic objects to devices can be edited as needed. The products include a library of standard graphic symbols, many of which, however, would not be applicable to the type of applications found in the experimental physics community.
Technical functions of SCADA:
The basic information that is collected through energy systems is referred to as data acquisition. Provides telemetry measurements and status indication to the operator.
Data acquisition functions:
Used to detect and handle error conditions
Reads power system data from 100-250RTUs.
Used to check operating limits, thermal limit, safe handling limit.
Used to convert analog data to binary data.
It stores only error free data
All products offer trend services and one can summarize common capabilities as follows:
The parameters to be displayed in a specific chart can be predefined or defined online.
A graphic can contain more than 8 parameters or pens with trend and you can display an unlimited number of graphics (restricted only by readability)
Historical and real-time trends are possible, although they are usually not on the same chart
The management of alarms is based on the verification of limits and status and is performed on the data servers. More complicated expressions can be developed (using arithmetic or logical expressions) by creating derived parameters in which the state or boundary verification is then performed.
Alarms are handled logically in a centralized manner, that is, information only exists in one place and all users see the same status (for example, acknowledgment of receipt), and multiple alarm priority levels are supported (in general, many more than 3 levels).
It is generally possible to group alarms and to handle these as an entity. it is possible to suppress alarms either individually or as a complete group.
The terms registration and archiving are often used to describe the same installation. However, the record can be considered as a medium-term storage of the data on the disk, while the file is a long-term storage of the data on the disk or other permanent storage media.
The registration is usually done in a cyclical way, that is, once a certain file size, period of time or number of points is reached, the data is overwritten. Data recording can be done at a set frequency, or only start if the value changes or when a specific predefined event occurs.
Registered data can be transferred to a file once the record is complete. Registered data is time-stamped and can be filtered when viewed by a user. The registration of user actions is generally done together with a user ID or a station ID. Often there is also a VCR installation to play archived data.
One can produce reports using SQL type queries for the file, RTDB or registers. Although it is sometimes possible to embed EXCEL graphics in the report, the ability to “cut and paste” is generally not provided. There are facilities to generate, print and archive reports automatically.