By Prasanth Gopalakrishnan
This article puts the standardisation process in perspective and discusses the need for an open protocol standard for metering communications in the Indian scenario and the applicability of IEC 62056/DLMS/ COSEM.
INDIA’S METERING SCENARIO
India’s electricity market has the unique problem of a high level of losses, theft and unbilled power at the distribution level. The major contributor to the losses is attributed to theft and there is a particular focus from the government as well as the utilities and manufacturers to address this issue. Thus over the years metering specifications and features have been increasingly adapted towards tamper detection in the meter.
In this context, constant monitoring and tracking of metering assets and usage is becoming key to all utilities. Likewise there is the requirement for utilities to deploy analysis and load management applications to manage their distribution networks and to make decisions on both immediate corrective actions and future investments.
To manage these requirements, the utilities have been resorting for some time to ordering not only the meter but also the metering software and communication system from a single vendor. In some cases utilities have duplicate systems from multiple vendors. Data integration occurs at a very high level, where the data from these different systems is aggregated in an enterprise resource planning (ERP)/ management information system (MIS). The resultant low degree of flexibility and high dependency on the vendors means resulting in reduced operational agility by utilities, as well as increased costs in deploying any new type of higher level management and reporting software or implementing large scale remote metering systems.
Over the years a number of metering protocols have come to exist in the Indian market. Among these are the older IEC 1107 standard, ANSI standard, PACT standard from secure meters and Modbus standard. A common meter reading instrument is available from many vendors, which supports manufacturer specific programmes that can read and convert the proprietary formats into user readable form.
These protocols have been modified by the manufacturers over time to meet local requirements from a functional aspect, especially with regard to theft and tampering. The manufacturers have also introduced new solutions to enable the utilities to deploy automated meter reading and other applications.
Indian utilities, however, have been largely ignorant on the communication issues and interoperability and open protocol requirements. Hence the metering protocol, as one of the critical components to be considered in a meter purchase, has tended to be left within the scope of the manufacturer. Furthermore, not only does each manufacturer have its own metering protocol but also there has been a reluctance to make these protocols public. As a consequence utilities have increasingly faced problems in being able to communicate seamlessly with their meters, without getting bogged down in the technical issues related to proprietary protocols, reading systems and the lack of common remote reading capabilities. Moreover they have been unable to deploy management information systems and applications with automated metering as input in any fruitful way.
The biggest drawback with the current system is the large investment being made by individual metering companies, system integrators, software implementers and the utilities themselves in maintaining their own set of communication protocols, drivers, adapters, XML converters, and application solutions. There have been a few instances of large AMR projects achieving low read success rates or even being shelved at the implementation stage, due to the lack of information on the communication protocol, resulting in wastage of money and lost opportunities.
IMPLEMENTATION OF A COMMON METERING STANDARD IN INDIA
It has been recognised and proven worldwide that standards help to reduce cost, improve competition and provide a more level playing field. This is true of all standards, including communication protocols. The communication itself never becomes the competitive advantage of a product, and this is dictated by the other features of the product.
Communication standards for utility automation, under IEC Working Group 13 of Technical Committee 57, is an example where different communication protocols have resulted in a higher level of interoperability, more competition and lower cost to end customers. Among these are protocols between a remote terminal and the control centre (IEC 60870-5-101/IEC 60870-5-104), between control centres (IEC 60870-6 or ICCP/TASE.2), within substations (IEC 61850), for relays and protection equipment (IEC 60870-5-103) and for demand management systems, as well as enterprise integration, asset management, trouble call management and between different energy participants and ISOs (IEC 61970/IEC 61968).
The TC 57 working group has also adopted DLMS/IEC 62056 as the standard for metering. This effort greatly enhances the value of DLMS as a universal standard for metering. Some of the key advantages of DLMS include its object oriented nature, support for different communication media including Ethernet TCP/IP, standardised object identification codes, thereby removing ambiguity, and a standard open communication profile addressing how the various devices can interoperate and communicate. The DLMS also provides a conformance standard that helps manufacturers and utilities ensure that suppliers comply with the standard.
India’s electricity network is slated to be the third largest in the world, and is rapidly expanding to meet the changing requirements brought about by exponential increase in demand, the deployment of large grids, large investments in distribution automation, a large rural electrification drive, and increasing focus on monitoring and control of billed and free power. All of the major utilities have adopted most of the protocols under TC57. It is important now that the communication aspects with respect to metering be standardised, as without this the whole concept of standardisation of products becomes irrelevant.
IMPLEMENTATION OF DLMS/COSEM IN THE INDIAN CONTEXT
Implementation of DLMS/COSEM in the Indian context throws open a Pandora’s Box with more questions than it can answer. The major constraint facing the local industry is the existing installed base of meters, which all have proprietary protocols. A two-step approach is required to tackle this problem, first to address the issue of the installed meter base, and second to plan for the new and expanding requirement of enhanced communicable standard meters for the future.
In addressing the first step the industry has to adopt the means to adapt to the new technology, while at the same time supporting, for a considerable period, the old installed base. The current approach to having an API for meter reading, with different protocol drivers for different meter models, is an intermediate solution as the industry migrates to the new technology. It must be noted that the current architecture for AMR and remote metering and meter reading results in increased meter reading time, enhanced investment in integration issues and implementation of own application software. However, this approach is inevitable to ensure that the current investments do not go to waste.
As a second step, all new tenders and procurements should be specified for DLMS meters. Indian manufacturers should not be disqualified in any tenders but should be allowed to quote for DLMS meters, providing they already have meters of the same class and a proven track record, albeit with proprietary interfaces. They would then take orders and implement DLMS compliant meters and DLMS compliant products duly certified by the Central Power Research Institute (CPRI).
There may be a need to develop India specific objects in DLMS, if it is found that the standard DLMS features cannot address local specific issues. It should be noted that globally intelligence in the meter to detect tampering has reached a saturation point, as the meters themselves have limitations on the number of parameters that can be analysed and the number of analyses that can be done. Hence, loading the meter with more capabilities that are very specific in nature would result in the long run in a nonstandard product, which would become costly to the utility while still not fully satisfying its requirements.
Effective control of losses as well as theft and tampering data can be obtained by increasing the number of metering points along the distribution network, along with the implementation of open AMR and energy management and distribution management systems. This would provide the utility with clear insight into the usage pattern of its customers and enable it to establish the points where energy loss and theft occur and to address the problem in a holistic and systematic way.
ADVANTAGES OF DLMS/COSEM TO THE INDIAN INDUSTRY
Adoption of DLMS/COSEM by Indian meter manufacturers would enable them to develop products which are future proof, have reduced integration costs, and enable the future applications for effective monitoring and control of electricity distribution and loss reduction in India.
If supported by Indian manufacturers DLMS/COSEM would enable them to compete on a level footing in the global market, as well as to develop new and innovative applications for the evolving requirements of energy savings, loss reduction, liberalised energy markets, energy trading, etc.
Also, with the increased use of gas in India, it would enable the use of meters for gas/water applications in the future, with a very similar protocol.
It is important to ensure that the Indian electrical metering industry and all its stakeholders, including the power ministry, Bureau of Indian Standards (BIS), Central Board of Irrigation and Power (CPIB) and CPRI, recognise and approve a common, open standard for metering communications. This will result in large savings in time, money and ease of deployment of advanced energy management and automation systems that will make the utilities competitive and profitable in the years to come.
This standard could be an open standard, like DLMS/ COSEM, or could follow a phased approach, in which Indian manufacturers open up their communication protocols for standardisation, and ultimately, drawing on global best practices, the development of an Indian standard. Globally it is recognised that open systems are cheaper and have fewer security problems than closed systems, and the Indian story must be no different.