India’s power transmission sector is rapidly adopting advanced technologies to enhance grid resilience and support rising renewable energy integration. By leveraging digital tools and technologies, new and advanced construction methods, and state-of-the-art solutions for asset management and maintenance, transmission utilities are improving operational efficiency, managing bi-directional energy flows and ensuring stable power evacuation.
Global Transmission Report looks at the new technologies and trends shaping the power transmission segment…
Substations and transformers
Advanced substation technologies are being adopted to improve grid efficiency, optimise space and tackle emerging challenges. Hybrid substations, combining air-insulated busbars with sulphur hexafluoride (SF6) gas-insulated switchgear (GIS), offer a compact solution for upgrading existing infrastructure, as seen in the 220 kV Hapur and Ghaziabad substations in the state of Uttar Pradesh. To address urban space constraints, utilities are exploring underground GIS substations, with state transmission company Karnataka Power Transmission Corporation Limited planning one in the city of Bengaluru. Additionally, eco-friendly alternatives are being introduced to replace SF6 gas and reduce environmental impact.
Digital substations employing IEC 61850 process and station buses, replacing conventional transformers with digital sensors, have been employed – reducing wiring costs, enhancing safety and minimising cybersecurity risks. A notable example is India’s largest transmission developer Power Grid Corporation of India Limited’s (POWERGRID) 400 kV Malerkotla digital substation in Punjab. The digital substation retrofitted the existing conventional Malerkotla substation (commissioned in 1992) with comprehensive digital technology.
Further, a fault current limiter offers an alternative to conventional methods for controlling short-circuit levels in substations where fault levels exceed or may exceed design limits. Unlike reactors or high-impedance transformers, it restricts fault currents without adding impedance during normal operation.
Mobile substations also serve as rapid-response solutions for emergency power restoration or temporary industrial power supply. Additionally, tank rupture-proof transformers improve safety in urban areas by preventing catastrophic failures. Meanwhile, the adoption of resin-impregnated paper and resin-impregnated synthetic bushings, which are more resilient than oil-impregnated paper bushings, has been mandated for 145 kV and above transformers.
Remote substation operation is another key technology trend. POWERGRID has set up the flagship National Transmission Asset Management Centre in Manesar, Haryana, which can remotely monitor the entire transmission system in real time. It has also taken up the development of autonomous robots powered with artificial intelligence (AI)/machine learning (ML) algorithms for detecting faults in substation equipment to ease routine inspection activities. Meanwhile, Bharat Heavy Electricals Limited (BHEL) has 3D modelling software with significant capabilities, particularly in managing large substations.
Renewable energy integration
The implementation of flexible AC transmission system (FACTS) devices, such as static synchronous compensators (STATCOMs) and static var compensators (SVCs), is enhancing grid stability and voltage regulation.
STATCOMs were considered for the first time in India with multivendor inverter-based resources at renewable energy pooling stations in the Rajasthan renewable energy complex. The presence of STATCOMs at strategic locations with unique control features near solar power parks enhances grid stability, improves power quality and facilitates the smooth integration of renewable energy sources into the existing power infrastructure. STATCOMs can provide dynamic reactive power support to regulate voltage levels, ensuring grid stability and reliability.
High voltage direct current (HVDC) projects are also expected to play a critical role in integrating renewable energy sources such as solar and wind power into the grid. According to the National Electricity Plan (NEP), during the 2027-32 period, around 32,250 MW of HVDC-based transfer capacity is expected to be added to the grid.
POWERGRID has successfully built several HVDC projects, including the Northeast–Agra link as well as the Raigarh–Pugalur project. The pipeline of HVDC projects is steadily growing. Recently, POWERGRID selected the consortium of Hitachi Energy India Limited and BHEL to design and execute the HVDC link to transmit renewable energy from Khavda in Gujarat to the industrial centre of Nagpur in Maharashtra. The ±800 kV, 6,000 MW bipole and bi-directional HVDC link is part of the transmission system to transfer power from the potential renewable energy zone in the Khavda area of Gujarat under Phase V (8 GW): Part A.
Another key upcoming project awarded recently is Rajasthan Part I Power Transmission Limited, a special purpose vehicle under Adani Energy Solutions Limited for the BF800 HVDC project. The letter of intent, which was awarded BHEL, is for the establishment of two line commutated converter (LCC)-based HVDC terminal stations of 6,000 MW at Bhadla, Rajasthan, and Fatehpur, Uttar Pradesh. The project features a ±800 kV HVDC LCC terminal station (4×1,500 MW) at Bhadla III and Fatehpur, along with associated AC substations. The project is expected to be completed by 2030.
Transmission lines and towers
Innovative technologies in transmission lines are being integrated to enhance capacity, optimise space utilisation and improve grid reliability. Insulated cross arms allow voltage upgradation and better ground clearance without increasing tower height, with successful implementations in Telangana and Kerala. Extra high voltage cross-linked polyethylene cables help mitigate right-of-way (RoW) challenges in urban areas, though they have length limitations, making gas-insulated lines (GILs) a viable alternative in high-power applications. High-performance conductors operate at higher temperatures, increasing power transfer without requiring major structural modifications, while photonic coatings on conductors enhance thermal radiation, improving capacity at the 66/132/220 kV levels.
Further, the covered conductors prevent electrocution risks in forested areas, reducing outages caused by vegetation contact. Dynamic line rating (DLR) optimises transmission capacity by adjusting to real-time weather conditions, especially wind speed. Monopole structures are increasingly preferred for their reduced footprint and faster deployment compared to lattice towers.
Further, GILs are being deployed in space-constrained areas despite their high cost, while travelling wave fault-locating technology is improving fault detection accuracy by identifying transmission faults within metres instead of kilometres, enhancing grid reliability and reducing downtime.
Monopoles and multi-circuit towers are also being adopted to conserve RoW in projects. Monopoles have distinct advantages over lattice towers, including lesser space utilisation, faster construction and quicker delivery. Emergency restoration system towers, also known as rapid restoration towers, are also being deployed to facilitate the rapid restoration of electrical power in the event of any damage or failure of high voltage transmission lines.
Traditional survey methods, such as walkover surveys, can be time-consuming and less accurate. To overcome these limitations, utilities are leveraging advanced technologies such as light detection and ranging (LiDAR) and drones for site assessments, topographic mapping, 3D visualisations and RoW estimations. Additionally, helicopters and drones equipped with LiDAR, thermovision cameras and corona cameras are being used by leading developers to enhance aerial patrolling, as well as the operations and maintenance (O&M) of transmission lines and towers.
Communications and cybersecurity
With the increasing complexity of grid management due to rising interconnections, renewable energy integration and smart grid applications, real time dynamic monitoring has become essential. Traditional supervisory control and data acquisition systems face latency issues, making technologies such as phasor measurement units (PMUs) and wide area measurement systems (WAMS) crucial for real time grid monitoring, enabling adaptive control mechanisms such as remedial action schemes and system integrated protection schemes. To support these high-bandwidth, low-latency applications, fibre optic communication systems, including optical ground wire (OPGW), underground fibre optic cables and all-dielectric self-supporting cables, are replacing power line carrier communication in transmission networks.
The Central Electricity Authority (CEA), India’s electricity planning agency, has mandated the installation of OPGW in all new 110 kV and above transmission lines as per its 2022 technical standards. Additionally, the transition from synchronous digital hierarchy and plesiochronous digital hierarchy to multiprotocol label switching is being explored for improved scalability, dynamic routing and bandwidth management.
Utilities have also developed cyber crisis management plans, while the National Critical Information Infrastructure Protection Centre safeguards critical infrastructure. The Ministry of Power has established the Computer Security Incident Response Team-Power to handle cyber incidents, and disaster recovery plans are in place. The Grid Controller of India Limited’s 24×7 security operations centre leverages AI/ML for threat mitigation, and the Cyber Swachhta Kendra monitors vulnerabilities.
Regular alerts, mock drills and cybersecurity training enhance resilience, and imported equipment is tested for cyber threats. Cybersecurity coordination forums address sector-specific security gaps, and audits are conducted to ensure vulnerabilities are resolved. The draft Cyber Security Regulations for the power sector are being developed to further enhance security measures.
Outlook
The integration of advanced technologies represents a transformative shift in India’s transmission sector, enhancing capacity, reducing losses, optimising power distribution and strengthening grid resilience. However, to fully realise these benefits, it is crucial to establish clear standards and regulations for implementation and operation. Additionally, skill development plays a vital role in supporting infrastructure growth, particularly in erection, commissioning, and operation and maintenance. As smart grids and automation become more prevalent, the demand for skilled professionals continues to rise. Looking ahead, continued advancements in automation, AI and energy storage will drive further innovation, ensuring India’s transmission infrastructure remains resilient, efficient and future-ready.
