In the distribution segment, utilities are embracing new technologies driven by the need to lower losses, ensure proper energy accounting, enable data-driven decision-making and deliver better services to end consumers. In conventional distribution equipment such as cables, switchgears and distribution transformers (DTs), utilities are introducing safety and efficiency improvements with the use of higher capacity conductors, gas-insulated switchgear (GIS) and dry-type transformers. Notably, a number of new and emerging technologies are also being introduced. Surveillance techniques that help improve safety, increase reliability and reduce response time across transmission and distribution (T&D) systems by deploying drones are being introduced. Further, utilities adopt technologies such as artificial intelligence (AI), machine learning (ML) and blockchain to augment equipment safety and customer service quality. A look at some of the new and emerging technology trends in the power distribution segment…
Conductors and cables
New conductors are being deployed for carrying higher currents, while allowing higher temperature ratings. The different types of conductors being used are all-aluminium conductors, all-alloy aluminium conductors, aluminium conductors steel reinforced, and aluminium alloy conductor steel reinforced. In addition, high-temperature low-sag conductors are increasingly being deployed. 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. The aluminium conductor composite core, gap type ZT aluminium conductor steel reinforced and super thermal aluminium clad INVAR reinforced conductors are some of the preferred options for reconductoring lines. Meanwhile, cross-linked polyethylene, high density polyethylene, aerial bunched cables (ABC) and spacer cable systems are the most commonly used covered cables. The use of ABC is widely gaining traction for overhead power distribution networks since it has benefit like low power loss, negligible current leakage, offers protection against power theft, requires low maintenance, displays lower fault rate and good protection against wind and falling trees.
DTs are the step down transformers that provide voltage transformation in the electric power distribution system, including the final stepping down of voltage to the level used by customers. 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. Also, these transformers offer better protection against fire hazards, have reduced/no risk of leakage of insulation fluids and entail minimal maintenance.
DTs are becoming an integral part of the new electricity grid, which independently regulates voltage and maintains contact with the smart grid in order to allow remote administration and real-time feedback on power supply parameters. The use of these transformers is gaining ground at the distribution and transmission levels. These transformers are equipped with intelligent electronic devices, and smart monitoring and diagnostics features.
In the switchgear segment, distribution utilities are increasingly opting for GIS, hybrid switchgear and intelligent switchgear. There has been growing traction in the deployment of GIS substations, primarily owing to their compact size. The other key features of GIS include high modularisation, high safety index and lower maintenance requirements, and their ability to resist vibration and avoid electromagnetic pollution. Further, as a GIS is housed in a metal enclosure, it offers protection against environmental conditions such as salt deposits in coastal areas, sandstorms and humidity, and thereby lowers operations and maintenance costs.
The use of hybrid switchgear is also fast gaining popularity, as it takes advantage of both air-insulated switchgear (AIS) and GIS technologies, striking a balance between the cost of land and the facility construction cost. Hybrid switchgear is compact with the functionality of AIS integrated into a gas-insulated enclosure. With hybrid switchgear, the bay length is reduced as the circuit breaker and the disconnector earth switch functions are integrated into one module. This results in an overall reduction in the area required for the substation. Further, the use of sulphur hexafluoride gas for encapsulation makes the maintenance of hybrid switchgear simple and cost effective.
Automatic meter reading (AMR) and advanced metering infrastructure (AMI) are the building blocks of smart meters and smart grids. Utilities are using both AMR and AMI for varied applications such as outage management and load balancing. AMI 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.
The main objective of AMI is to enable two-way communication between a smart meter and a head-end system. It enables remote reading, monitoring and control of electrical energy meters (consumer, feeder and DT meters) to serve as a repository of record for all raw, validated and edited data.
Smart meters provide information that provides valuable consumer insights and allows utilities to enhance customer satisfaction. Another application of smart meters stems from whose utility as net meters that allows 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 internet of things.
Blockchain and AI
Blockchain, AI and ML are the other key emerging technologies in the distribution segment. Blockchain is a distributed data processing technology, that which enables all users participating in the network to distribute and store data. Applying blockchain technology to the smart grid will ensure secure management of the energy data and contribute to the development of the future smart energy industry. As per a recent NITI Aayog study, blockchain may enable a sustainable energy trading system by implementing smart purchase power agreements, smart microgrids and issuance of renewable energy certificates. Making energy resources into digital assets that can be traded on a blockchain could open new investing and trading opportunities, allowing ease of entry to new players and fostering innovations.
Other new emerging technologies such as 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 and requirements of utilities as well as the desired outcome. AI and ML modules could be developed based on the analytics of the data collected 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 among companies is the use of conversational AI or chatbots to navigate common customer queries. Another valuable use for discoms for AI in customer service is improving compliance and quality assurance in call centres.
Drones are another new and emerging technology in the power distribution segment assisting utilities in maintaining and inspecting T&D lines, which can otherwise be difficult, dangerous and costly. Drones drastically cut costs of power line inspections for utilities. They also improve safety, increase reliability and reduce response time across T&D systems.
Accessing remote areas of high voltage power lines, either when conducting routine inspections or surveying damage after storms, presents difficulties and dangerous obstacles. With the help of drones, these difficulties could be eliminated. Drones also give utilities the ability to quickly and efficiently identify threats to the energy grid.
Drones can capture more than just an image. By collecting data that provides operational information and construction details, drones have the ability to assist engineers in the process of designing the electrical infrastructure. For example, light detection and ranging (LiDAR) is a remote sensing technology that measures distance by using a laser. The data is generated as 3D images, which are then utilised by many design applications.
Recently, in February 2020, BSES Rajdhani Power Limited (BRPL) has started using drones to map its distribution assets, for detection of power theft, inspection of rooftop solar installations and accurate assessment of rooftop solar potential, and assessment of vegetation encroachment (around discom infrastructure). Using high resolution imagery and infrared thermal scanning, Drone will involve inspection of the overhead lines and equipment, grid substations, connections, damaged switches, capacitors, detection of equipment theft and intelligent line profiling. 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.
Earlier, in July 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 T&D networks for faults and fix supply disruptions. The micro drones deployed by the company weigh less than 2 kg, have a flying capacity below 200 feet and are equipped with an integrated thermal vision camera to render infrared radiations, LiDAR to measure distances with the use of laser lights, high resolution camera for electrical asset inspection, monitoring, mapping and global positioning system-enabled autopilot system, guided by a ground control station.
To conclude, the adoption of emerging technologies for power by state discoms distribution equipment is expected to pick up pace driven by strong government policy support.