Smart Metering

Architecture, implementation and key benefits

The total installed generation capacity in the country reached 255.71 GW and the combined transmission capacity stood at 306,685 ckt. km as of December 2014, according to the Central Electricity Authority. However, the distribution segment continued to be the weakest link in the sector.

The distribution segment requires a complete overhaul given its poor financial and operational performance. Many state power distribution utilities are in a state of bankruptcy, and are  unable to run their businesses or repay their debt.

The annual aggregate technical and commercial (AT&C) losses in the distribution segment were around 25.37 per cent as of December 2014. Around 300 million people still do not have access to electricity. India’s per capita annual electricity consumption is close to 780 kWh, which is among the lowest in the world.

Besides the high AT&C losses, the distribution segment is characterised by inefficiency, frequent interruptions in supply, poor power quality, and lack of coordination among different entities of the system. The key causes of such inefficiencies in the distribution segment are political interference, unscientific tariff setting, populist government policies like subsidies, improper metering, and poor record keeping.

Several reform measures have been initiated on the policy front to improve the health of the segment, including the unbundling of utilities, corporatisation, privatisation, and the Restructured Accelerated Power Development and Reforms Programme. The India Smart Grid Vision, which aims to transform the sector and provide quality power to all by 2027, is another key initiative in this regard.

On the technology front, there is an urgent need for reform measures to ensure the implementation of smart metering. Aside from helping to maintain the commercial viability of the distribution segment, smart metering will facilitate the development of a new business model geared towards much-needed investments for capacity addition and efficiency of operations with the help of private participation.

Smart metering

Conventional meter reading involves the utility staff taking readings manually. This process is time-consuming and may result in errors. Moreover, only a limited set of parameters is taken into account in this method, which is useful only for billing purposes.

Modern electronic static energy meters are capable of sensing, measuring, computing various electrical parameters and storing them for a set period of time. They are also equipped to detect and record any tampering attempts along with the date and time.

Smart meters are static energy meters with a digital display and bidirectional communication facility with a connect/disconnect load switch to physically connect or disconnect the consumer as per the decision made by the utility. They can also communicate requested data as per programmed intervals, remotely configure, interface to home area networks (HANs) and compatible devices, display utility alerts and messages on home display units, record consumption at intervals of an hour or less and allow time-of-use recording and support remote load management/curtailment.

Advanced metering infrastructure (AMI) provides two-way communication, allowing commands to be sent to the consumer for multiple purposes like time-of-use pricing information, demand response actions and remote programming. AMI is the main component of smart metering infrastructure. It is also most important carrier of the power supply relationship in the smart grid system.

Proposed communication architecture of smart meters in India

The proposed communication architecture consists of the following main components: a metering and control block, metering protocol and communication modules.

The metering and control block consists of a smart meter and its load switch control arrangements. The smart meter and metrological requirements should meet the stipulations of the latest version of the IS 13779 standard.

The performance of the load switch is checked by a load switching capability test, a performance requirements for load switching test, and a specified rating test. The test conditions and test parameters should adhere to the latest version of the Indian standard for prepayment meters (IS 15884:2010).

For the second component, metering protocol, meter data and commands are exchanged as per the IS 15959 standard. The Indian Companion Specification for the IEC 62056 series of standards has defined the minimum requirement for the meter to support data communication between the meter and the data collecting unit.

The third component, the communication modules, should be provided with inbuilt transceiver modules for two-way communication with a data concentrator unit or head-end system, optical port for local communication, inbuilt communication module neighbourhood area network for meter-to-data concentrator or directly for the wide area network. It should have one additional port for IHD or HAN. The maximum number of ports available should be three.

New power system business model

Earlier, utilities had a vertical integration business model with unidirectional power flows. With the introduction of smart technologies, the flow of information and power has become multidirectional. Customers are becoming more demanding and feeding the grid with extra power. They are trying to optimise the use of present assets, driven by demand response, load profile flexibility, distributed power generation and storage capability.

Customers want to know the details of their energy usage and the price they are paying for it. Business models that cater to these requirements are known as platform models.

The term platform refers to a common architecture and a set of rules to provide standard foundation governing transactions between two or more parties of the electricity value chain. The platform provides an energy marketing portal through which customers can get the best deals on buying and selling electricity. All information and money is exchanged through this portal. The platform provides information to customers about the efficient use of available energy in order to minimise electricity bills.

Indian smart metering projects

The India Smart Grid Task Force (ISGTF), under the aegis of the Ministry of Power, has approved 14 pilot projects to be implemented across the country. The functionalities covered in these projects include: AMI, peak load management, outage management, power quality management, distributed generation and microgrids.

The Puducherry Electricity Department and Power Grid Corporation of India Limited have jointly implemented the Puducherry Smart Grid Pilot Project. The project deployed 87,031 smart meters of various makes. Different communication technologies have also been implemented under the project in collaboration with 60 service providers. This project, which is based on narrowband and broadband power line communication at 865 MHz and 2.4 GHz respectively, also covers distribution transformer monitoring solutions, fault passage indicators, smart street lighting systems, renewable energy integration through net metering, etc.

Conclusion

Smart metering is beneficial for consumers as well as for utilities. With real-time data display, smart metering is making consumers more aware about the optimum utilisation of energy. With the help of load connect and disconnect features, utilities are finding new ways to shift peak loads and it is becoming easier to track tampering. Real-time data communicated by smart meters is also useful for distribution automation. Using smart metering technologies, utilities can, therefore, supply reliable and quality power to their customers.

Based on presentations by Priyamvada Chandel, Engineering Officer, Central Power Research Institute (CPRI), Bhopal; B.A. Sawale, Joint Director and Head, Energy Meter Test Laboratory, CPRI, Bhopal; and Tripta Thakur, Professor, National Institute of Technology, MANIT, Bhopal, at the India Smart Grid Week 2015

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