SMART ENERGY METERS

Smart Energy Meters

These Energy Meters are the latest meters and they are not in their final shape. Rapid advancements are coming in it day by day. They can not only measure energy units but also send those units to the utility company through some communication medium like GSM/GPRS, RF, PLC (Power Line Communication) etc. Through these mediums company can control the load of consumer as well. While doing these basic responsibilities, these meters can also b used for load management and load forecasting purposes.

Smart energy meter is an electronic device that measures the most accurate amount of electricity consumed by a residence, business or any electrically-powered device. A smart meter is reliable source for most accurate information of consumed energy that reduces the chance of error in the existing billing system to minimal.

Smart meter comprise first-generation smart meters or AMR meters and second-generation meters or AMI meters. AMR meters provide for self-health check of the meter, data communication using secure and open standard protocols, periodic upgrade of meter software remotely over the transmission network, multi-utility metering capabilities, consumption data acquisition and demand management and control. Comparatively, AMI meters or smart meters provide effecting utilisation and management of metering data, automatic management of meters, two-way communication with meters, demand response capabilities and further provides data to implement energy efficiency practices.

A smart meter is an electronic device that records consumption of electric energy and communicates the information to the electricity supplier for monitoring and billing. Smart meters typically record energy hourly or more frequently, and report at least daily.

Smart meters enable two-way communication between the meter and the central system. Such an advanced metering infrastructure (AMI) differs from automatic meter reading (AMR) in that it enables two-way communication between the meter and the supplier. Communications from the meter to the network may be wireless, or via fixed wired connections such as power line carrier (PLC). Wireless communication options in common use include cellular communications (which can be expensive), Wi-Fi (readily available), wireless ad hoc networks over Wi-Fi, wireless mesh networks, low power long range wireless (LoRa), ZigBee (low power, low data rate wireless), and Wi-SUN (Smart Utility Networks).

It is an advanced metering technology involving placing intelligent meters to read, process and feedback the data to customers. It measures energy consumption, remotely switches the supply to customers and remotely controls the maximum electricity consumption. Smart metering system uses the advanced metering infrastructure system technology for better performance.

These are capable of communicating in both directions. They can transmit the data to the utilities like energy consumption, parameter values, alarms, etc and also can receive information from utilities such as automatic meter reading system, reconnect/disconnect instructions, upgrading of meter software’s and other important messages.

These meters reduce the need to visit while taking or reading monthly bill. Modems are used in these smart meters to facilitate communication systems such as telephone, wireless, fiber cable, power line communications. Another advantage of smart metering is complete avoidance of tampering of energy meter where there is scope of using power in an illegal way.

Parameters measured by the device

1. Units of the month
2. Bill of the month
3. Real power
4. Load on line

Feature of smart energy meter

1. Highly accurate
2. Real-time operation, we can see graph of energy consumption.
3. Fully automatic means amount will be paid automatically.
4. Live billing display in mobile.
5. Get bill in one missed call

Smart Meter Includes

a. Meter, which is used to measure the flow of electric power from input to the output terminal.

b. LCD Display, which is used for displaying readings of the parameters that are being metered and

c. Communication, which is present in modern electricity meters, which is used for one-way or two-way communication of information with the billing utility

The smart meter which need to be considered for the electronic circuit design.

Power supply:

This section of the smart meter powers the circuitry for the meter and also provides battery back-up as well as protection against transients etc.

Measurement capability:

This section of the smart energy meter block diagram addresses the basic measurement of the utility that is used. It requires to be reliable and accurate. It will typically output the data in a digital format and will therefore include a analogue to digital converter.

Processing:

Any meter like this will require manipulation of the data. It needs to be formatted to send via the communications links as well as displaying on the smart meter itself.

Communications:

The smart meter needs to communicate the information back to the utility supplier for billing and management of their smart grid. It also needs to provide information to the user on a smart energy monitor or In-Home Display, IHD. A variety of different communications methods can be used for this including cellular communications, power-line communications, Zigbee, etc.

The different areas of the circuit block diagram have separate functions and often very different forms of electronic circuit.

Power supply

The power supply section for the smart energy meter has some interesting and challenging design constraints.

The power supply technology will use a switched mode technique. This ensures the highest level of efficiency and reduces the current drain caused by the smart meters – an important feature when many millions of them are to be used.

The switch mode power supply, SMPS will take in the line alternating current signal and convert this to the required DC voltage or voltages required to drive all the meter functions. Typically this will be 5volts or below.

The SMPS will also be used to ensure the battery backup is fully charged if a rechargeable battery is used for this purpose. It will also include an electronic switch to change over to the battery backup should the line AC be interrupted for any reason.

The other main function within the power supply region of the meter is to protect the circuitry from any line transients that may appear. Note it will not be used to protect any equipment outside the meter, such as the equipment for which the consumption is being monitored by the smart meter.

The transient protection is typically provided by a combination of an input inductor and varistors – electronic components which absorb transients above a certain voltage. Metal oxide varistors are widely used for this.

In addition to this the input inductor as well as a high voltage differential filter are needed to give good EMC performance. Not only is it necessary for any interference that might be created by the smart meter to be removed before it reaches the power line, but it is also necessary to ensure that the meter operation is not affected by any interference that may appear on the power line.