Modern Power Substations

When discussing the technologies trending in power substations, the industry’s leading power experts emphasise the importance of digitalisation, as well as the evolution of Gas Insulated Substations and pre-fabricated substations, which are expected to drive substation demand. 

Trends in substation automation A Gas Insulated Substation (GIS) is a high-voltage substation where the major conducting structures are contained within a sealed environment with a dielectric gas known as SF6 (sulphur hexafluoride gas) as an insulating medium.

The total space required for a GIS is a tenth of the space needed for a conventional air insulated substation (AIS) facility. While the conventional AIS requires several feet of air insulation to isolate the conductor, SF6 takes just a few inches, allowing a GIS facility to fit into an area smaller than an AIS facility.

On a related note, as per the views of Rajesh Suri, Head – Design & Engineering, Sterlite Power Transmission Limited, “When you look at considering gas insulated substation, we put everything indoors; whether it’s a breaker module, disconnector module, busbar module, everything is placed indoors.” This indirectly leads to an increase in the costs as the indoor PEB building becomes bigger with a larger footprint. When the substation owner isn’t comfortable with placing the GIS modules outdoors, it is suggested to keep the breaker module or disconnector module inside the building and have a conventional AIS busbar outside as it doesn’t require an indoor ambience. This doesn’t increase the land availability further, and hence the entire process is done on the basis of cost-of-ownership. Moreover, while these technologies are working well in foreign countries, we can definitely have them installed in India.” 

According to Sanjay Udgikar, Chief Risk & Contracts Officer, Manav Energy Pvt. Ltd., “Technology in substation automation has been continuously moving towards smart equipment, communication, and networking which can also monitor their functionality. While conventional substations have primary equipment hardwired to secondary protection and control devices which makes installation, commissioning, and maintenance difficult and time consuming, the arrival of IEC 61850-based modern digital substations Intelligent Electronic Devices (IEDs), IIoT, and Ethernet technology-based digital communication have helped utilities to improve and simplify this aspect enormously. 

Secondly, deployment of Hybrid Gas Insulated Substations are gaining momentum, as they employ GIS bay modules in Air Insulated Sub-stations; thus enhancing deployment and expansion capabilities. Even the prefabricated substations are trending as they considerably minimise the installation time, eliminating heavy civil work, while managing the managing space requirements efficiently.

Maintaining an efficient power supply with a digital substation and modern equipment

According to H C Sharma, Chief – Business Development, Contracts, Stores & Technical Services, Tata Power-DDL, “Digital substations and modern power equipment can reduce copper infusion into a system, which, as a result, increases the reliability of an efficient power supply. In the meantime, it is also important to have an alchemical rectification. But for that, we need to work on the development of indigenous products that can complement our substations very well. Whenever we witness a failure in our substation, and if we have connected them to our OEMs, we approach their MNC’s Indian representatives. We will even share our experience if there is a failure in the substations because we have connections with OEMs and all like to come back to those people who are in India as representatives of those MNCs. Although we have digital tools and technologies, we couldn’t find the skilled manpower for maintenance. This issue exists with MNCs too. So, I believe we need to find ways to increase the availability of skilled manpower, whether it is for a supplier, owner, or a developer, for that matter.

Commenting on the key maintenance aspects, Sanjay believes that the electricity networks have rapidly evolved in the last decade. While Power generation is increasingly distributed and random, the demand for quality power and uninterrupted power supply is more substantial by the day. A significant focus on carbon footprint is driving the need for environmental-friendly technology in transmission and distribution. The necessity for optimising cost, space, and time in installation and maintenance is also a significant parameter to consider.

Moreover Traditional power system does not have capabilities of digital communication and remote monitoring. Similarly, deployment of conventional sub-stations is time-consuming; they are increasingly inefficient due to aging infrastructure, and maintenance is resource-heavy. The system needs to address operational efficiency and reduce life cycle costs. Digital substations also provide higher safety due to separation of interfaces and higher flexibility due to simpler architecture making future expansion easier.

Advanced design tools to detect a developing fall in IED or EED 

The availability of advanced digital tools depends upon the product capability or the algorithm of relay. Elaborating this aspect even further, Sunish Sukumaran, Head–Design & Application Engineering, GE, says “If you take a protection relay, it has no means or the algorithms to take care of these developing tools and technologies to address these faults in India. In other words, it depends on the kind of protection relays available. This helps us understand its utility scale and the area of its application. On understanding them, we can select the protection relay and maintain them.” 

Whereas, Sanjay explains that the traditional power system does not have capabilities of digital communication and remote monitoring. Similarly, deployment of conventional sub-stations is time-consuming; they are increasingly inefficient due to aging infrastructure, and maintenance is resource-heavy. The system needs to address operational efficiency and reduce life cycle costs. This is where digital substations score much higher in having efficient power transmission through the integration of fiber-optic cabling, sensors, protection relays, controllers, alarm and position indicators, tripping signals, measuring and recording IEDs, and operational communication network providing cyber security to ensure real-time data transmission, remote monitoring, and diagnostics.

Improving operational efficiency and cost reduction 

Elaborating on the significance of improving operational efficiencies and reliability from the design and engineering perspective, Sunish says, “Today, we consider automation and digitalisation while designing a substation, right at its primitive stage. We already have conventional specifications and conventional substations for the utilities while migrating towards newer technologies. Technically, we are optimising the performance without compromising the efficiency of the performance. Secondly, we need to look at merging the unit yards to keep the performance uptight even during difficult environmental and geographical conditions. It’s moving away from the pilot stage to a real commercial project. Many of the customers have already started commercial projects. 

Adding more to the discussion, Sanjay shares the significance of earthing systems as it plays a key role in power system installations. Hence, it’s critical to maintain its health so as to ensure safe and reliable operation of power system equipment, especially during fault incidents/conditions leading to high energy dissipation. It plays a vital role in managing the risk to people, livestock, and assets.

We have also developed an offering, particularly for protecting the lives of humans and livestock, whereby a lightning management system is combined with an audio visual annunciation system that can be customised to the terrain. Apart from predicting the occurrence of lightning based on the surrounding environment, the system also provides an audio-visual warning when such an event is about to occur, which allows people to take precautions and necessary safety measures. 

Operation efficiencies and cost reduction are two important matters. When we talk about increasing operational efficiencies, automation and allied technologies definitely comes into the picture-whether it is for operations, maintenance, or engaging skilled manpower. “Digitalisation and digital tools help identify and detect faults in a power substation right from the outset of the fault occurrence and notify us in advance so that preventive measures can be taken,” says HC Sharma.

To maintain the same, we have several self-monitoring systems available. These are pre-defined based on the data available from the equipment, which can be further analysed to take preventive precautionary actions accordingly and ensure reliable output and operational efficiency by the utility. This emphasises the very fact that digitalisation and automation are two of the critical yet essential aspects for the power sector. “Furthermore, we see widespread acceptance for the same in the Indian power sector, with utilities taking all possible steps to implement it and making room for automation, digitalisation, and other allied technologies to improve overall output,” HC Sharma concludes. 

Sterlite Power was a pioneer in the Gurgaon area for multilayer vertical GIS substations. Rajesh Suri, Head – Design & Engineering, Sterlite Power Transmission Limited

Although we have digital tools and technologies, we couldn’t find the skilled manpower for maintenance.
H C Sharma, Chief – Business Development, Contracts, Stores & Technical Services, Tata Power-DDL

The availability of advanced digital tools for substations and automated substation depends upon the product capability or the algorithm of relay.
Sunish Sukumaran, Head–Design & Application Engineering, GE 

A major component to consider is the need to optimise cost, space, and time in installation and maintenance.
Sanjay Udgikar, Chief Risk & Contracts Officer, Manav Energy Pvt. Ltd.