Hardware, standards and schemes required for digital substations

Substation transformation

Revolution in information technology brought enormous influence on electrical power system by the application of intelligence in metering, protection, monitoring and control. New communications made possible to monitor and control in real time, from a central place, by SCADA for the operation of power generation, transmission and distribution.

A hierarchical structure exists in the transmission and distribution of power since the power is received at a high voltage level in a substation and delivered to a load center through another substation at reduced voltage level.

These substations are being transformed from hardwired configurations to a networked platform by leveraging the technological advancements. The technological transformations have brought within its purview comprehensive automation of substation.

This paper talks on all the required hardware, standards and schemes pertaining to the digital substations thus evolved, where the information acquisition, transmission and its processing is completely digitized.

Also, this paper highlights the case study of a real time process control scheme.

Need for automation

The economic growth and development of a country depends heavily on the reliability of electric power supply. Generally, rigorous planning is done for addition of the generation and expansion of the transmission networks.

Efficient operation and maintenance of distribution system are hampered by non-availability of system topological information, current health information of distribution components such as distribution transformers, feeder historical data etc.

Another reason includes the lack of efficient tools for operational planning and advance methodology for quick fault detection, isolation and service
restoration etc.

All these lead to the increase system losses, poor quality and reliability of power supply in addition to the increase in demand.