In India, electronic energy meters are fast replacing the conventional Ferraris meters. This transformation is primarily due to several drivers.
These drivers are:
- Power sector reforms, and a deregulation process being vigorously implemented by federal and state governments.
- The formation of privately-owned distribution companies with a mandate to improve revenues and efficiency in system operations, and to improve customer satisfaction.
- Standardisation and adoption of state-of-the-art technologies.
India has a large electricity customer base – in Asia, the country occupies second position, after China. There are about 120 million consumers – approximately 90 million domestic, 13 million agricultural, 12 million commercial, 3 million industrial, 3 million others (public lighting, waterworks etc.)
The current pattern of deployment of electronic energy meters is as follows:
- Heavy industry: 100%
- Light industry: About 30%
- Commercial: About 30%
- Domestic: About 10 %.
Broadly the meter requirements in India can be broken down into several categories.
Single phase meters: These are whole current meters with a range of 5 to 60A (10-40 is common) and are of class 1 accuracy. In most cases a 6-digit EM counter display of energy (kWh) is required. More recently meters with energy, demand (kW) and dual tariffs with LCD display, as well as some amount of storing capacity, are being specified. Tamper conditions include accurate functioning of the meter in the event of phase reversal, CT reversal and current drawn through earth (load is connected to earth instead of returning to neutral). These meters are mainly deployed in the domestic sector, and the annual requirement is of the order of 3 to 4 million. The price is US$10 to US$12.
- The market demand for three phase meters can be divided into four main categories.3-phase energy meters displaying only kHz on a 6 digit counter, and with tamper features like phase missing, neutral missing, phase reversal, CT reversal. Quantities required range from 1.5 to 2 million per annum, at a price of US$20 to US$22. Most of them are based on ASIC.
- 3-phase kWh and KVA (demand) meters with LCD display and an MD resetting capability. Tamper features call for accurate functioning of the meter in the event of removal of neutral or any two phases. The meter should also function accurately if the current is drawn through earth instead of neutral, and it should be able to detect and record CT disconnection. The demand for this type of meter is on the increase in the agricultural sector, and quantities required are around 1 million a year, at a price of between US$40 and US$45.
- 3-phase multi-parameter LCD display meters (kWh, KW, KVA, V/ph, I/ph, pf, frequency, tamper), with MD reset and all the above tamper conditions, including detection and recording with time stamping. Quantities required are approximately 100,000 a year. Prices range from US$70 to US$80. These meters are based on ASIC and micro-controller/DSP technology, and are used mainly for light industrial and commercial applications.
All the above meters are 1% accuracy and are whole current type. The current range is 10 to 80A.
- 0.5.class meters are generally installed in industry, and should offer all the tamper features mentioned above, as well as load survey, multi tariff, and time of use features. Prices range from US$90 to US$120. Demand is about 30,000 per year.
All quantities and prices are indicative in nature.
Recent technological advances
Some technological advances have a direct impact on electronic energy meters – in particular advances made in product technology covering semi conductors, surface mounted technology (SMT) components, manufacturing methods and testing equipment, as well as advances in AMR systems. They include:
- ASIC (Application Specific Integrated Circuit) technology permitting large-scale integration of various metering functions into one chip.
- Masked versions of micro-controllers, resulting in low-cost micro-controllers.
- Digital Signal Processor (DSP) for handling large- scale computation – useful in high-end industrial meters and power quality measurements.
- Surface mounted components resulting in high miniaturisation and space saving.
- Non-volatile memory (EEPROM) that needs no battery back up, and that can be used to retain consumer data for at least 10 years.
- From conventional through whole components, the technology has moved towards surface mounted devices.
- The manual/semi/automatic wave soldering process has given place to fully computerised automated production processes involving glue dispensers, pick and place machines, IR reflow ovens and so on.
- Fully automated processes result in predictable process times, consistent quality and reliability.
- On-line manufacturing defect analysis eliminates rework and associated quality problems.
Testing and calibration
- State-of-the-art computerised testing and calibration systems can handle a large batch of meters without human intervention.
- There is no scope for data manipulation.
- Test results of individual meters are stored in a database for future retrieval.
- The meter manufacturing data can be traded at any time.
- An in-built quality analysis system is available.
Meter reading systems
Recent advances made in the fields of information technology and communications are major contributing factors in the evolution of state-of-the-art meter reading systems.
- Today’s handheld meter reading unit is based on a handheld computer, unlike older MRIs which were based on microprocessor technology.
- Today’s meter reading systems support a host of networking protocols and communication interfaces, making their integration with a utility’s IT environment an easy task.
- Advances in low powered radio technology, powerline carrier communications, GSM technology and fibre communications have led to the design and implementation of cost- effective AMR systems. Pay back periods range from 2 to 5 years, compared to 5 to 10 years.
In India AMR is still at a concept stage, and many utilities are keenly following the trends in more advanced nations. Recently Emco Ltd, a company based at Thane, has reported the successful commissioning of a pilot project for Maharashtra State Electricity Board, consisting of a walk-by system based on low powered radio modules and electronic energy meters. A few Indian utilities are planning pilots in the following areas:
- Low powered radio technology
- Walk-by and drive-by AMR systems
- Powerline carrier communications for connect- ing the meter to the utility computers.
- AMR through the PSTN telephone network.
All these technological advances have made it possible to design, produce and supply electronic energy meters which meet various customer requirements on a large scale, at prices that provide value for money. Other important benefits include high reliability, due to the fact that ASIC and DSP technologies need fewer components; short delivery times, due to automated and computerised manufacturing and testing facilities; retention of consumer data in non-volatile memory, resulting in no data loss during power outages; and easy upgradeability.
Today’s electronic energy meter is no longer just a black box that registers active energy, but an intelligent and smart device that offers a host of multi-functional features, such as:
- Measurement of active, reactive and apparent energy.
- Computation of current and maximum demand.
- Multi-tariff programming.
- Time-of-day (useful for flattening the load curve).
- Detection and recording of tamper, peak load and maximum demand violations.
- Load survey (storing of consumer usage data between one to three months).
- Harmonics measurement (useful in power quality measurement).
- Accuracy classes ranging from 0.1 to 2 %, depending on the application.
Utilities employing electronic meters have reported increased revenues in the order of 20-25% in the first six months of installation. Tamper detection features have resulted in large-scale theft detection. This in turn has acted as a major deterrent for would-be tamperers, and has allowed utilities to accrue higher revenues in the form of penalties. Utilities also report that operating costs have come down considerably, due to fewer maintenance and inspection visits.
India has emerged as one of the major markets for electronic energy meters. The large-scale development of electronic meters and proactive government policies have encouraged many meter manufacturers to operate in the country. As an example, at least three leading electronic meter manufactures have installed capacities exceeding 1 million meters per year.
The Indian Standard IS 13779 is more stringent than IEC 1036. Several independent test laboratories such as NPL (National Physical Laboratory) and CPRI (Central Power Research Institute) undertake type testing and certification of meters.
Meter designs take into account the fact that most of India experiences tropical weather. In addition Indian specifications regarding how the meter functions under tamper conditions are very stringent.
With state-of-the-art design, manufacture and testing facilities backed up by an excellent vendor base and talented and trained manpower, India has emerged as a major and mature market for electronic energy meters. The time is apt now for international players in the metering industry to focus on India as an attractive destination for investing in off-shore facilities to serve their clientele with highly cost-effective and quality products.
Post time: May-09-2017