Smart Grid Standards

A key priority for ensuring system interoperability

As India looks to expand its smart grid programme, it is imperative to establish standards and specifications for the same. Various smart grid components such as smart meters, smart sensors on distribution lines, microgrids, power quality monitoring systems, asset management systems, as well as condition monitoring devices are a part of the pilot projects being implemented in several states. Without adequate standards in place, the technologies being developed and implemented in these projects may become obsolete prematurely or lack the necessary security features. Considering these technologies involve significant capital investments, this is undesirable.

Globally, various standard-making bodies such as the International Electrotechnical Commission (IEC), the Institute of Electrical and Electronics Engineers, the National Institute of Standards and Technology and the European Committee for Electrotechnical Standardization are engaged in developing standards for smart grids. In India, the Bureau of Indian Standards (BIS) is engaged in this task with support from the India Smart Grid Forum (ISGF) and other power sector stakeholders.

As per the Smart Grid Vision and Roadmap for India released in August 2013, the development of the first set of Indian smart grid standards was envisaged by 2014. However, little progress has been made since. The Central Electricity Authority (CEA) released the technical standards for the connectivity of renewable sources of energy to the high voltage grid and distributed generation sources, including rooftop solar, to the low voltage grid in October 2013.

Standards for smart metering systems are still under development although smart metering through advanced metering infrastructure has been accorded high priority in the government’s flagship Integrated Power Development Scheme (IPDS) and ongoing smart grid pilot projects. The CEA had also released a report outlining the functional requirements of smart meters. In addition, the BIS’s Electrotechnical Technical Committee had notified certain metering standards, some of which are currently being used. These include IS 13779:1999, IS 14697: 1999, IS 15884:2010 and IS 15959:2010.

Since a smart grid is a complex system, a common understanding of its major building blocks and how they interrelate must be broadly shared. This calls for the active involvement of Indian experts as well as international bodies engaged in smart grid standards development. In this context, the ISGF and the Smart Grid Interoperability Panel (SGIP) signed an MoU proposing an approach to enhance the coordination between the two organisations at the SGIP conference in October 2014. The MoU focuses on sharing information for a standardisation policy, smart grid projects, testing and certification, cybersecurity requirements and technologies, as well as policy and regulation issues.

Eventually, the smart grid will require a host of standards and specifications. However, some of these need to be put in place on a more urgent basis than others. Therefore, it is important to identify the priority areas. Some of these  are demand response and consumer energy efficiency, wide area situational awareness, advanced metering infrastructure, distribution grid management, cybersecurity, and network communications.

Interoperability

Interoperability essentially refers to the ease and ability with which different components of a networked system can communicate effectively with each other. Achieving interoperability across the power sector is a huge task and requires standards in different areas. Within a smart grid, different components of the grid communicate with each other across distinct interfaces, and interoperability is required at each such interface of the communicating entities.

The interoperability framework should ideally be flexible, uniform and technology-neutral, and be able to accommodate traditional, centralised generation as well as upcoming distributed resources besides smart technologies. Also, the interoperability standards should be developed and maintained through a collaborative, consensus-driven process that is open to participation by all stakeholders. Further, these standards should be readily and reasonably available for smart grid applications.

Interoperability standards are required for communication between substations, field equipment, utility control centres, energy service providers, regulators and consumers. Interoperability occurs at various levels or layers, which cover the details of the technology involved to link systems together. Broadly, there are three such levels –

communication technology (CT), information technology (IT) and operational technology (OT). OT justifies the need for information exchange, IT confirms what information is to be exchanged, and CT formulates the path for the information exchange.

At the CT level, interoperability is required to address the technical aspects of communication between the two systems. The specifications of basic physical medium of connection, the network addressing and identification mechanism, and the protocols for communication are defined at this level. At the IT level, the semantics of the content that is communicated is standardised. Although basic connectivity protocols are met and a certain amount of information is communicated between two systems without interoperability, the information may not be useful until it is semantically understood on a common basis. This can be achieved by conforming to a standard information model at a higher level of interoperability while communicating information. At the OT level, the business context for communication between any two systems needs to be standardised. This defines the high-level functions or services that are to be carried out to achieve certain organisational objectives.

Given that the grid is constantly expanding, the approach of ensuring layers of interoperability would help utilities replace individual components of the system without the need for replacing the entire solution. For example, ensuring interoperability at each layer would facilitate the replacement of the CT without any changes in the IT and OT layers. Therefore, the cost implications of not having interoperability would be quite high for utilities.

The way forward

Given the government’s increasing focus on the expansion of renewable energy, significant capacity is expected to be added to the grid in the next five years. This comes with its own set of challenges. Therefore, the industry needs standards for connectivity and operations that can evolve according to its changing needs. Also, storage technology is expected to grow significantly in the future and, therefore, standards have to be developed for it. Similarly, standards for electrical vehicles and their charging infrastructure will be another area of focus in the future.

Also, inputs from the current government programmes such as the IPDS and the Deendayal Upadhyaya Gram Jyoti Yojana can be fed into the smart grid, thereby accelerating the deployment of smart technologies. This would require a thorough technical evaluation of the standards for smart grid extendibility in towns covered under the Restructured Accelerated Power Development and Reforms Programme (R-APDRP) (now subsumed under the IPDS). In addition to the technical issues related to data standards for consumer indexing, geographic information system, asset mapping, billing, etc., a business model should be formulated to reuse and extend functionalities under smart grids. Also, there should be coordination between state-level and other activities outside the R-APDRP; for instance, all new metering deployments henceforth including single-phase consumer meters should be based on standards such as DLMS/COSEM (IEC 62056) so that they are smart grid-ready.

In sum, standards and interoperability are necessary to ensure that smart devices interoperate in a secure environment as new digital technologies are implemented throughout the electricity delivery system, advancing the economic and energy security of the country. However, care should be taken to ensure that standards and interoperability related activities are not limited only to technical information standards but are also expanded in line with business processes, markets and the regulatory environment.

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