Utility communication makes enormous contributions to the lives of power and grid managers, says Saurabh Srivastava.

As someone who has witnessed the remarkable evolution of utility communications first-hand, I'd like to share a fascinating narrative that spans over decades. It's a story of technological progression from the traditional, non-communicative electrical systems to the interconnected, intelligent networks that power our world today.

The early days: The birth of intelligent devices

Back in 1996, during the early days of my career with a switchgear company, I encountered electrical relays that captivated me with their intelligence and functionality. These devices were pivotal in understanding network disturbances and were responsible for operating breakers to disconnect from active circuits in case of faults. Relays were expected to have four basic qualities: Reliability, Sensitivity, Selectivity and Speed. At that time relays were mainly electromechanical, using disk and plunger mechanisms, and they operated in isolation without any means to communicate.

The dawn of communication: Static type relays

By 1999, relay manufacturers began introducing relays with communication features, utilising proprietary protocols like LON bus, K bus, Spa bus, Profibus, etc. This was a significant step from the non-communicative electromechanical relays to communicable static type relays. Communication had started with overcurrent relays which were the main relays in 6.6kV or 11kV switchgears. The excitement in the industry was palpable as we learned about the advantages of serial communication. With RS 232 port or RS 485 port allowing for communication speeds between 9.6kbps and 19.6kbps, this was a breakthrough in utility communications.

Embracing Ethernet: High-speed data transfer and interoperability

This excitement lasted for about 3-4 years and then the evolution of Ethernet started in utility communications.

The early 2000s marked the entrance of Ethernet, offering high-speed data transfer, robustness, and a more scalable and reliable alternative to serial communication. By leveraging TCP/IP protocols, Ethernet facilitated seamless integration with existing IT infrastructure. This also helped utilities to adapt standard networking solutions.

One of the key advancements facilitated by Ethernet was the transition to IP-based communication protocols, such as Modbus TCP and DNP3 over IP. These protocols not only offered higher data transfer rates but also provided enhanced security features, real-time monitoring, and interoperability with a wide range of devices and systems. All the major relay manufacturers in India embraced this technology and started offering Ethernet based relays, etc.

Energy meters also started to communicate by this time, however they were on Modbus TCP/IP. However, relay networks and meter networks remained distinct entities.

Overcoming vendor lock-in: The introduction of IEC61850

One of the biggest challenges in the early 2000s was vendor lock-in. Customers confined to a single relay vendor often faced price escalations and increased total

cost of ownership (TCO). In response to this issue, the interoperable IEC61850 protocol was introduced between 2003 and 2004. It allowed utilities to use devices from different manufacturers seamlessly. It also featured GOOSE (Generic Object-Oriented Substation Event) communication for prioritised emergency messaging.

In India, Siemens, ABB, and GE were the pioneers of IEC61850 technology, with the Power Grid Corporation of India Ltd (PGCIL) being the first to implement it in 2004. This protocol marked a transition from ‘Master-Slave topology’ to ‘Client-Server topology’ with speeds reaching 1MBPS, which was impressive for that time. And once PGCIL became confident with this protocol, other utilities started testing and using numerical relays with this protocol as well.

The present and future: From substations to control centres

Transmission substations were early adopters of this new technology which was later adopted by generation and distribution utilities as well. Today, Ethernet LANs operate at speeds from 100MBPS to 1GBPS, and we continue to expect more. Beyond substation automation as we move to the control centre level, our speeds have already increased from 1GBPS to 10GBPS. Today as we explore the possibilities of integrating IT networks with OT networks – though it is still in its early stages – I realise just how much we've evolved. We’ve gone from having no communication devices in substations to having fully communicable relays, meters and tap changer controllers in all types of substations. And now, from substations to control centres, communication is making a significant difference in the lives of utilities.

In the past, paper registers at substations were used to manually record events and fault records for various feeders. These records were entirely dependent on the operator's vigilance. Now, data from every millisecond is captured in relays, which explain what happened and why it happened in power networks. Event records and fault records can be transmitted from relays to the substation level and from there to control centres in a very short time. I still remember blackouts, which used to be very common during my childhood days in northern India. Today, power is available round the clock in almost every part of our country. In 2017, India became a power surplus nation for the first time, and has since continued to grow strongly in this sector. According to the Statista report of 2022, India is now the third largest energy producer in the world, after China and the USA

Utility communication plays a significant role in ensuring power availability. By knowing the technical parameters of each feeder, as well as event and fault records through numerical relays, meters and other communicable devices, we can conduct fault analysis and take the necessary actions to make electrical networks stronger, more reliable and healthier from substation level to control centres.

Communication via smart meters also plays a very key role in improving the transparency of distribution networks. As a country, we have significantly reduced power theft through smart meters and other efforts, and have already seen substantial improvements in ATC (aggregated technical and commercial)  losses, from 53% in 2002 to 15-17% in 2023.

Communication from one transmission substation to another has also been greatly improved, shifting from PLCC (Power Line Carrier and Communication) to OPGW (Optical Ground Wire) where optical fibre is used as a ground wire over transmission lines. Here, Fibre Optic Terminal Equipment (FOTE) is used to transmit data at high speeds, and now discussions are underway to adopt MLPS technology to further increase the speed, security and bandwidth of transmission.

Utility communication has come as a blessing for power utilities. It ensures that the power scheduled for generation is indeed generated. Once generated, it ensures that proper transmission corridors are available to evacuate the power, and once evacuated and delivered to distribution substations. It is then distributed efficiently to consumers. It is metered and billed appropriately, which is crucial for collecting revenue from consumers to maintain the health and hygiene of the power sector. Utility communication at all these steps makes enormous contributions to the lives of power and grid managers, enabling them to manage the entire value chain of power generation and distribution.

Article Courtesy: NASSCOM Community – an open knowledge sharing platform for the Indian technology industry: https://community.nasscom.in/communities/energy-utilities/evolution-utility-communications-substations-smart-grids

Saurabh Srivastava is Head-Utilities – Digital Transformation Office at Cisco India. His core competencies include business development and sales, customer relationship management and digital grid technologies. Saurabh is passionate about supporting the energy transition and the adoption of renewables and green technologies which enables round-the-clock power availability from renewable sources, modelling green hydrogen and ammonia production, capacity expansion planning, and scheduling. He also has extensive experience in selling and implementing digital grid solutions, such as protection relays, substation automation, cybersecurity, grid IoT, energy efficiency, and power quality, for various segments of the power sector, such as utilities, industries, and infrastructure.

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