Automatic meter reading (AMR) has been in practice for the past several decades as it offers online monitoring of consumer behaviour and consumption patterns. It allows much better revenue protection and consumer service owing to intense periodic monitoring. Automatic grids and smart grids, both of which do not require manual intervention, are the next to be deployed, as they offer two-way communication to execute the commands and ensure better control. Over the past 10 to 15 years, the concept of two-way communication has been extended to even low-end single-phase metering. What prompted utilities to adopt this technology for smaller consumers was mainly ease of remote disconnections and reconnections, and flexibility to consumers. Smart meters are capable of working in the prepaid mode. This can free up discom staff from metering, billing and collection functions and allow them to focus on operations and maintenance (O&M), revenue protection and customer care.
There are a host of other functions that can be accomplished by deploying smart meters (as part of advanced metering infrastructure) and the list of such functions is endless. Smart meters can detect the first breath (power on) and the last gasp (power off) condition, and send it to the head end system. This paper aims at bringing to light some of the other uses of smart meters and their capabilities. Some of the use cases of continuous availability of data and features of smart metering are:
Automatic consumer tagging to a distribution transformer (DT): In a normal functioning system, a simple command to disconnect the smart meter installed on a particular DT may be executed. All the other smart meters installed in the adjoining areas that stop communicating automatically get tagged to that particular DT. Similarly, disconnecting a phase on the low tension (LT) that is, if the facility to disconnect only a phase has been enabled side will also tag the non-communicating consumer meters to that particular LT feeder.
Revenue protection by way of online availability of consumer data: Several meter data management (MDM) systems already have an inbuilt integrated module of analytics and loss prevention based on the continuous availability of data from every individual consumer, and this has been very well documented. Zero load conditions of consumers along with time-stamped load survey of DT versus the sum total (Sigma) of all indexed consumers provide the time and other specific loss information for a pinpointed action plan. For example, zero loads at night in hot summer may indicate a commercial consumer who has shut the shop, or a domestic consumer not at home, or else pilferage.
Fault or disconnection in capacitor bank: Sudden change in the power factor of any DT meter or feeder meter is indicative of abrupt switching of large inductive load or fault/disconnection of capacitor bank(s). If the drop is only of a transient nature, it is indicative of sudden switching of inductive load whereas the non-transient drop indicates a faulty/switched-off capacitor bank which may call for site inspection and restoration. Similarly, a poor power factor on a continuous basis may require installation of capacitor banks at certain load points or DTs.
Fault or overloading of LT lines: A significant voltage difference at a DT meter and a tail-end consumer connected to this DT is indicative of overloading of this line or any other line fault which needs the attention of the O&M staff of the utility. Similarly, voltage or current difference between the different phases of a DT indicates a load imbalance, which needs to be attended to. Simply put, voltage regulation of LT lines from source to user end provides inputs to work out the need for augmentation and maintenance of the network.
Fault or overloading of feeders: If feeders are also installed with smart meters, similar inputs (as in the case of DT and LT lines) would be available for them. This would lead to similar diagnostics.
Quality of DT: Change in the voltage profile of a DT at no load and at full load is an indicator of the quality of the DT. The poor voltage regulation may cause a significant loss of energy to the utility.
Consumer delight and DSM measures for discoms: Consumers can definitely take full advantage of lower rates of electricity wherever time-of-day tariff is applicable. Also, it can help the utility to offer incentives to consumers for compliance with their DSM initiatives.
Besides, as and when content and carriage (network owner and power supply business) is separated (as is the case in parts of North America and Europe) and there are multiple suppliers of electricity, the use of smart meters would become necessary to facilitate the billing of such multiple players.
Some of the above features may soon be realised by manufactures of MDM. However, the possibilities for future are really endless with the integration of relays and switches with smart meters. Some of the possibilities of a well-integrated smart home are:
- Switching on and setting the temperature of your room well before you arrive home will result in much increased comfort and energy saving.
- Lowering the temperature of your fridge to chill your drinks minutes before you arrive.
- Switching on the microwave to prepare your food just when you arrive home.
- Continuous surveillance of your home or your child’s room through a web-cam integrated with your smart meters.
In sum, smart meters perform several innovative functions and are popular in advanced countries. They can be extremely effective in reducing aggregate technical and commercial losses besides continuously monitoring network health in Asian countries.
As and when this happens, smart meters will not only become an electricity meter with much more flexibility but also a true controller and watchdog of smart homes. Utilities deploying smart meters can then become integrated service providers rather than being just electricity suppliers.
By Arun Kumar Kanchan, Director, Power, Bajaj Energy, and Ravindra Kumar Jain, Superintending Engineer and In-charge, Metering, Billing & Collection Cell, Uttar Pradesh Power Corporation Limited