Technology advancements have helped in the overhaul and transformation of the traditional electric power grid into a smart grid. However, this, in turn, has transformed the electric grid into a complex network of networks, which comprises both power and communication infrastructure and various intelligent electronic devices (IEDs).
There are various communication technologies and architectures involved in a smart grid. The communication networks provide the necessary infrastructure that allows utilities to manage IEDs from a central location. In addition, these networks are designed to accommodate a variety of smart grid applications. In recent times, besides advanced metering infrastructure, utilities are on the look-out for communications solutions for outage management, leak detection, remote shut-off, lightning control, distribution automation, geographic information systems, demand response, as well as home area networks. Each of the applications requires a communication and networking technology that has a suitable speed, is reliable and secure. Therefore, it is important to select the right kind of communication technology for the successful roll-out of any smart grid programme.
Moreover, as we transition towards smart grid infrastructure, huge volumes of data are generated from different applications for analysis, control and real-time pricing methods. Hence, it is critical for utilities to define the communication requirements and discover the best communication infrastructure to handle the output data and deliver a reliable, secure and cost-effective service.
Smart grid communication infrastructure requires two-way communication, interoperability between advanced applications and end-to-end reliable and secure communication with low latencies and sufficient bandwidth.
There are certain key communication infrastructure requirements that need to be taken into account for the successful implementation of a reliable smart grid. For instance, smart grid components like smart meters may be present in remote areas or at inconvenient locations in urban areas, making it difficult for a communications network to penetrate. Hence, it is imperative to ensure that the communication infrastructure is capable of providing universal coverage.
The second key requirement is the ability of the network to support multiple applications. The constant evolution of smart grid technologies to include more solutions for utilities and customers necessitates the deployment of a robust communication network, which has the bandwidth and interoperability to support multiple applications in the future. The communications network should be standards based and not proprietary. It must be designed keeping in mind future needs, that is, it should be flexible to accommodate future technologies.
In addition, the technologies should be resilient against intrusion and other malicious activities. The system security should be robust to prevent cyberattacks and must provide system reliability and stability with advanced controls. Moreover, utilities require a network that allows them to prioritise the data collected from various applications on the network.
All these requirements are largely met by the long range radio (LRR) technology, which is a dedicated radio solution operating at a frequency lower than the general packet radio service.
LRR is a fixed-base communication technology, which can not only support smart grids and smart meters but also smart street lighting and smart water networks. It operates on a dedicated licensed spectrum, and thereby ensures security and provides utilities with a resilient and universal solution. The spectrum used may be different in each country; however, it should be selected in such a manner that it is ideally suited for long-range communication and has excellent building penetration characteristics, thus making it suitable for indoor connections. LRR has additional characteristics, which are different from point-to-point or session-based radio communication networks.
The main feature of LRR technology is that it allows for universal coverage. It is designed to provide more than 99 per cent connectivity in existing locations, thereby enabling the integration of a geographical area or citywide networks with a single technology. Hence, there is no need for additional technology to “fill in the gaps”. Further, LRR offers high connectivity performance to the existing meter points, better building penetration than other frequencies used to carry data such as cellular networks and WiFi, long range, and the necessary capacity to support multiple utilities (electricity, gas and water) on a single communications infrastructure.
Another key feature is long-term resilience. This feature provides over-the-air updates and modulation type upgrades, and facilitates innovation and changes to service requirements during its service life without the need to visit the endpoint. Even during an outage in the base station, the endpoints will have the capability to communicate with the neighbouring points.
LRR technology also offers direct to meter benefits, which helps in maintaining the independence of the meter supply market. As such, it improves the accountability of communication performance right through to the meters and offers a clear line of demarcation for installation and maintenance.
Moreover, LRR offers utilities a secure system on dedicated radio spectrum. Private key encryption at the endpoint level is set at the point of manufacture with individual key encryption for each smart endpoint.
The successful implementation of smart grid projects is contingent on the technology deployed for the systems’ communication infrastructure. The installed communication networks need to be based on proven technology that is affordable, and offers high connectivity and operational performance over its long service life. In this regard, LRR has been found to more or less exceed the expectations of utilities for smart grid communication network.
Successful trials have demonstrated that LRR technology is well-suited to reach the smart meters and other devices that have been deployed in hard-to-reach locations. Moreover, being a single-technology solution with a nearly 99 per cent success rate in terms of first-time installation and with no requirements of street level equipment, LRR technology entails a low cost of ownership. It also reduces operational complexity and provides for simpler integration, testing and commercial arrangements. Based on a technical paper presented by Deepak Naik, Principal Solution Architect, Sensus, at the India Smart Grid Week 2016.
The following are some countries and regions where LRR technology has been deployed.
- LRR technology has been implemented in different locations in the US. These include rural, semi-urban, urban and dense urban areas. It has also been deployed by utilities in the states of Alabama, Maryland, Georgia and Nevada for their respective smart grid applications.
- In August 2013, the UK government selected LRR as one of the communications technologies for its smart grid programme. The technology will operate on a 400 MHz licensed band and will be deployed across northern England and Scotland. LRR will connect about 16 million electric and gas meters across 10 million homes and small businesses in the region. The network is expected to cover an area of about 113,255 square km, representing approximately 50 per cent of the coverage area in the UK.
- LRR communication technology trials on 280 MHz band have been successfully performed in dense urban areas in Tokyo, Japan. The results obtained from the observed band were quite positive, especially for radio propagation, diffraction and building penetration performance. These 280 MHz LRR connectivity advantages are slightly better than the existing systems and are suitable for multiple applications of wireless sensor networks including the smart metering network.