With the growing emphasis on digitalisation and communication technologies, utilities across the country have stepped up efforts to strengthen their ecosystems. Discoms in particular, have been deploying technologies such as smart meters and automated metering infrastructure (AMI) to enhance efficiency and improve monitoring. Smart meters enable two-way communication between the meter and the central monitoring system, thereby enabling remote monitoring. Further, with analytics, AMI can facilitate the creation of a huge data pool that can be analysed and utilised to deliver better results. However, as smart grids gain momentum and technology advances further, network communication requirements also need to evolve.
Communication technology options in metering
Robust communication technologies enable the utility to undertake demand response, enforce the sanctioned load limits and detect tampering and theft. Four basic networks form the backbone of a holistic communication network – wide area network (WAN), neighbourhood area network (NAN), local area network (LAN) and home area network (HAN). WAN requires long distance communication solutions and considerable bandwidth to operate whereas for deploying NAN, a reliable communication solution encompassing all smart meters in the neighbourhood is required. HAN, however, requires a short distance communication solution and low-output power devices in the case of wireless solutions.
Each of these networks caters to the specific requirements of the utilities. WAN solutions include multiprotocol label switching (MPLS) to create virtual private networks (VPNs), optic fibre cable (OFC) for high bandwidths, 3G/4G solutions and microwave. However, each of these options poses a challenge. In the case of OFC for instance, right of way for laying cables and the maintenance of aerial OFC in urban and suburban areas act as major hindrances. For microwave, line of sight and the availability of the frequency system need to be dealt with. Network congestion and the lack of coverage in rural areas add to the difficulties of installing 3G/4G solutions.
Meanwhile, NAN offers a wide range of solutions such as the wireless radio frequency (RF) mesh for an interconnected reliable system, power line carrier (PLC) for the transmission of high speed data signals from one device to an other, and Wi-Fi and OFC-fibre-to-the-home (FTTH) solutions for economical delivery of data services and operating multiple applications through the same medium. However, these solutions also face issues such as spectral pollution, poor condition of the infrastructure, line-of-sight constraints and lack of customer participation. LAN and HAN offer solutions on similar lines with the ultimate objective of developing a reliable and efficient communication system.
Communication infrastructure requirements
As per the Central Electricity Authority’s (CEA) AMI functional requirement guidelines, the communication infrastructure should either be based on the RF mesh network, PLC, the cellular network or a combination of these. Moreover, these communication networks must be in line with the prescribed standards. The guidelines also specify certain conditions for the AMI implementing agency. The agency, for instance, must design an interference-free communication network that should be flexible enough to be used in variable terrain and function in high urban density areas. In addition, the network solution should be equipped with a disaster recovery mechanism and a suitable network management system (NMS) to monitor the performance of the communication network. The NMS enables the parameterisation of networking devices and nodes. Further, to protect the network from theft and other malpractices, adequate cybersecurity measures must be taken. These include secure access controls, authorisation controls and malicious software protection. The CEA guidelines also provide detailed requirements for network elements depending on the kind of network used.
Challenges and the way forward
Infrastructural inadequacy remains the biggest impediment to the development of a robust and reliable communication network. Several communication solutions can utilise the lines and cables already present, provided they are in good health. Further, clearances and approvals continue to plague the sector, thereby delaying the entire process. Utilities, too, need to complement smart metering systems with related software such as supervisory control and data acquisition systems to leverage the technology more fully.
As increasing renewable energy capacity is integrated with the grid, the existing communication technologies would have to be upgraded. Moreover, with rapid technological advancements, it becomes imperative for utilities to identify the appropriate technology and conduct a detailed cost-benefit analysis to gauge its feasibility. Lastly, with increasing interconnectedness, security measures need to be revised and strengthened to protect the ecosystem.
With inputs from a presentation by Santanu Sen, Deputy General Manager, Testing, CESC