Power distribution utilities are increasingly adopting new and advanced technologies to improve operations. For equipment such as cables, switchgear and distribution transformers (DTs), they are introducing various safety and efficiency improvements. They are also undertaking several digitalisation and grid modernisation initiatives such as smart metering and smart grids in order to lower distribution losses, ensure proper energy accounting, enable data-driven decision-making and deliver better services to end consumers, more so, in the Covid-19 situation. Technologies such as internet of things (IoT), artificial intelligence (AI), machine learning (ML) and blockchain are the new and emerging technologies that can help enhance situational awareness, intelligence, control and security to transform the grid into an intelligent cyber-enabled one.
A look at the key technology trends in the power distribution segment…
Conductors and cables: The commonly used types of conductors in the distribution segment are all-aluminium conductors, all-alloy aluminium conductors, aluminium conductors steel reinforced, and aluminium alloy conductor steel reinforced. New conductors are being deployed for carrying higher currents, while allowing higher temperature ratings, such as high temperature low sag conductors. These are made up of materials such as INVAR steel, aluminium-zirconium alloys and metal and polymer matrix composites that offer higher temperature resistance and increased ampacity. Cross-linked polyethylene, high density polyethylene, aerial bunched (AB) cables and spacer cable systems are the most commonly used covered cables. The use of AB cables is widely gaining traction for overhead power distribution networks since these provide higher safety and reliability and lowers power losses, besides providing economy by reducing installation, maintenance and operational costs. The AB cable system is ideal for rural distribution and in difficult terrains such as hilly regions, forest areas and coastal areas. Underground cables help in providing reliable power supply, do not require right-of-way clearances, offer protection against theft and enhance city aesthetics. With these benefits, they are increasingly being adopted to meet the objectives envisaged under various government schemes such as the Integrated Power Development Scheme and the Smart Cities Mission.
DTs: Currently, most utilities in the country deploy oil-cooled (mineral oil)-type transformers. However, the use of dry-
type transformers and K-class (ester) fluid-filled transformers is on the rise since they are associated with lower failure rates, offer better protection against fire hazards, have reduced/no risk of leakage of insulation fluids and entail minimal maintenance. DTs are now equipped with intelligent electronic devices and smart monitoring and diagnostics features, which help in maintaining contact with the smart grid, in order to allow remote administration and real-time feedback on power supply parameters.
Switchgear: Distribution utilities are increasingly moving from air-insulated switchgear (AIS) to gas-insulated switchgear (GIS), hybrid switchgear and intelligent switchgear. The growing traction for GIS arises primarily from its compact size, high modularisation, high safety index, ability to resist vibration and avoid electromagnetic pollution, besides reducing operations and maintenance costs. Hybrid switchgear, on the other hand, takes advantage of both AIS and GIS technologies, striking a balance between the land cost and facility construction cost. Further, the use of sulphur hexafluoride gas for encapsulation makes maintenance of hybrid switchgear simple and cost effective.
Smart meters: Advanced metering infrastructure is an integrated system of technologies involving smart meters and enabling communication networks and data management systems that provide enhanced capabilities over traditional analog or digital meters. Smart meters give us information that provides valuable consumer insights and allows utilities to enhance customer satisfaction. Another application of smart meters stems from their use as net meters that allow meters to read both conventional and non-conventional sources of energy. Further, smart meters would allow discoms to roll out add-on services such as home automation and distributed energy resource management, thereby entering into the domain of smart grids and IoT. The ongoing Covid-19 crisis has highlighted the inability of utilities to conduct physical meter reading, thus hampering their revenues and leading to poor financial performance. The crisis has highlighted the benefits of smart metering. For instance, Madhya Pradesh Poorv Kshetra Vidyut Vitaran Company Limited’s smart metering project, which entailed the installation of about 140,000 smart meters in the Indore Smart City, is one of the biggest in terms of smart meter installations in the country and has been functioning successfully. This has given the network self-healing capabilities and better reliability, thus helping the utility achieve 100 per cent readability. Smart metering has particularly helped the discom during the Covid-19 pandemic by enabling it to obtain remote meter readings.
Blockchain: Blockchain, AI and ML are some of the other key emerging technologies in the distribution segment. Blockchain is a distributed data processing technology, that enables all users participating in the network to distribute and store data. As per a recent NITI Aayog study, blockchain may enable a sustainable energy trading system by implementing smart power purchase agreements, smart microgrids and issuing of renewable energy certificates. Making energy resources into digital assets that can be traded on a blockchain could open new investment and trading opportunities, allowing ease of entry to new players and fostering of innovations. BSES Rajdhani Power Limited (BRPL), one of the leading private discoms in the country, underlook a peer-to-peer (P2P)-based solar trading pilot project in November 2019. The trial project covered a select group of consumers in gated communities with 300 kW of solar capacity at Dwarka in Delhi. These consumers were able to trade solar power with their neighbouring apartments and buildings using the blockchain platform rather than letting it spill back into the grid. About 25 MWh of electricity was traded between the peers, accounting for a share of 40 per cent in total transactions.
Also, the Uttar Pradesh Electricity Regulatory Commission has approved a pilot project for P2P power transactions from rooftop solar systems using blockchain technology. Under this pilot project, the fees for blockchain technology will be recovered in the aggregate revenue requirement of the concerned distribution licensee. By using this technology, participants will be able to transfer funds, settle trades, or vote without seeking approval of the certifying authority.
AI and drone-based maintenance: According to experts, the Covid-19 pandemic has necessitated accelerated adoption of AI-based technologies. The use of AI and drone technologies for asset surveying and maintenance (real-time monitoring of assets and predicting faults, if any) in power distribution would soon become a reality or the new normal. In February 2020, BRPL started using drones to map its distribution assets, and for the detection of power theft, inspection of rooftop solar installations, accurate assessment of rooftop solar potential and assessment of vegetation encroachment (around the discom infrastructure). BRPL had undertaken a pilot project at the 66 kV Paschim Vihar grid station, using drones, along with two towers of 66 kV Bodella 1-Paschim Vihar Circuits 1 and 2 and 33 kV Mukherjee Park Circuit 3, near Chaukhandi. In 2019, Tata Power Delhi Distribution Limited initiated the use of drones for maintenance of its power lines, poles and towers to detect power theft and monitor transmission and distribution networks for faults and fix supply disruptions. The micro drones deployed by the company weigh less than 2 kg, have a flying capacity of below 200 feet and are equipped with an integrated thermal vision camera to render infrared radiations, LiDAR (light detection and ranging) technology to measure distances with the use of laser lights, high resolution camera for electrical asset inspection, monitoring and mapping and a global positioning system-enabled autopilot system, guided by a ground control station.
Other emerging technologies: AI and ML hold the potential to significantly transform the way power is generated and distributed. These can be used across the value chain, based on the needs of the utilities as well as the desired outcomes. AI and ML modules could be developed based on analytics of the collected data by sensors installed in the system. AI and ML can help turn information into actionable insights that can help predict network failures, plan timely interventions and avoid customer interruptions. Another popular scenario that is seen is companies using conversational AI or chatbots to navigate common customer queries. A private discom, CESC Limited, has introduced a chatbot on its website for common consumer queries and interactions. The solution, called e-buddy, encourages consumers to report power cuts, enquire about AC connection or post other queries without having to dial the call centre. Equipped with AI, ML and natural language processing capabilities, the chatbot can also transfer the consumers to a live agent.
Outlook
The adoption of digitalisation and automation has so far been slow and limited across utilities in India because of the lack of understanding about the core aspects of IoT and its implementation. However, the Covid-19 pandemic has brought into sharp focus the need to rethink strategies and obtain smarter solutions for ease of doing business. Although the Covid-19 pandemic has hit the current financial position of discoms, it is likely to boost radical technological advancements, going forward.