Technological advancements and innovations are transforming the electricity distribution landscape of utilities across the world. This is being driven mainly by the rapid electrification of sectors like transportation, expansion of decentralised generation with the declining cost of renewable energy, and digitisation of the grid with the advent of smart sensors and internet of things (IoT)-based devices. These trends are gradually making their way into the power sector as well. Some distribution utilities are looking at ways to modernise their networks in a small yet significant manner, given the paucity of funds on account of their poor financial health.
Power Line presents an overview of the existing and emerging technology trends in the distribution segment…
Equipment technology trends
Distribution utilities continue to focus on deploying equipment that requires less right of way (RoW) and ensures greater safety in operations. For instance, underground cables and covered overhead conductors such as cross-linked polyethylene (XLPE) conductors and aerial bunched cables are being preferred over conventional cables. In addition, the uptake of dry-type and K-Class fluid-filled transformers, which are associated with lower failure rates, has increased. The use of dry-type transformers and ester fluid-filled transformers is on the rise as they offer better protection against fire hazards, have reduced/no risk of leakage of insulation fluids, and entail minimal maintenance.
In the switchgear segment, distribution utilities are switching to gas-insulated switchgear (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, lower maintenance requirements, and the 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 (O&M) 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 in 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.
While these technology trends are here to stay in the short to medium term, the technological requirements of utilities are expected to change gradually with the changing energy mix on account of greater integration of renewables and varying loads due to the growth of EVs and installation of digital equipment on consumer premises.
Emerging technology trends
As the country gears up to meet the target of 100 per cent electric vechile (EV) sales by 2030, the demand for EV charging stations and battery storage solutions is expected to grow exponentially. The adoption of EVs can provide an opportunity to optimise electricity consumption and balance the grid given that appropriate pricing and smart charging solutions are deployed. The standards and specifications for EV charging stations are still work-in-progress and most discoms are currently setting up EV charging stations as pilot projects.
The growth of net metering policies across states has given an opportunity to consumers to become “prosumers” by feeding electricity generated from rooftop solar photovoltaic panels installed on their premises back to the grid. With this, the distribution grid has become more active as power is flowing in both directions and utilities need technologies to monitor and manage the flow of electricity in real time. In addition, advanced load forecasting technologies are required to deal with the changing load profile as customers become less dependent on central generation to meet their electricity demand.
Digitisation allows equipment across the distribution grid to communicate with each other as well as the utility and/or consumer to facilitate better O&M of the grid and enhanced consumer services. Smart meters, intelligent electronic devices (IEDs), IoT sensors, and control and automation software are critical components of digital solutions.
Intelligent substations based on the IEC 61850 protocol and smart transformers that can be controlled in real time are key emerging digital solutions. These solutions deploy intelligent switchgear, which can connect with the internet and provide comprehensive monitoring and protection as well as measure all electrical parameters in real time to ensure remote monitoring.
Further, these offer built-in protection and control IEDs. These new IEDs, combined with the latest information and communication technologies, form a base for enhanced protection, control and monitoring. In the metering segment, smart meters are emerging in a big way, riding on government schemes like the Ujwal Discom Assurance Yojana and smart meter pilot projects.
In line with these trends, policymakers need to devise a plan for the deployment of infrastructure that meets the needs of future power distribution systems.