The document describes a proposed automated wireless meter reading system. It would consist of meter reading retrieval units with microcontrollers and Zigbee transceivers attached to electricity meters. A wireless personal area network using Zigbee would transfer meter readings to a handheld device. This would allow readings to be collected remotely without manual inspection, reducing costs and errors. Digital meters would measure voltage, current and power consumption. Readings would be sent via Zigbee and stored on the handheld device for later transfer to a computer database. The system aims to make meter reading easier, more accurate and help utilities better manage electricity distribution.
1. Major Project on
“AUTOMATED WIRELESS METER READING”
Under the guidance of: By:
Dr. K. P. Shivamurthy Gaurav(1SI09EE016)
Associate Professor Pallavi Singh(1SI09EE036)
Dept. of E&EE Ruchi (1SI09EE046)
S.I.T, Tumkur Nishant(1SI09EE063)
2. Introduction
With growing population and number of houses it is
very difficult to measure and record power
consumption in urban areas.
Skyscrapers make it still difficult for manual meter
reading as it is time consuming and prone to human
errors.
It is very much required that an automated meter
reading system must be evolved so that the process of
recording of energy consumption in households and
industry can be made easier and accurate.
3. Literature Survey
As commercial use of electric energy spread in the
1880s, it became increasingly important that an
electric energy meter should be employed.
When electricity was commercialized there were no
electric meters, instead they use to bill for a fixed
number of lamps per month.
Several attempts were made by the great scientists to
develop a device to measure the amount of electric
energy consumed known as Electricity energy
meter.
4. What is an Electricity energy meter?
It is a device that measures the amount of electric
energy consumed by a residence, business or an electrically
powered device. Electricity meters are typically calibrated
in billing units, the most common one being the kilowatt
hour [kWh].
Electricity meters operate by continuously measuring the
instantaneous voltage (volts) and current (amperes) and
finding the product of these to give
instantaneous electrical power (watts) which is
then integrated against time to give energy used
(in joules, kilowatt-hours etc.).
5. Problems With The Existing Energy Meter
A great number of inspectors have to be employed for
reading the meters.
Sending out bills is an expensive procedure.
Processing payments is even more
expensive, requiring a large number of employees.
Single tariff constrains effective usage of electricity.
Power distribution companies can't discourage peak
time usage by extremely high tariff .
7. Automated Metering System
This system will comprise of :-
Meter Reading Retrieval Unit which consists 8-bit
Atmel Mega32 Microcontrollers (AVR) and Zigbee
interface for high speed data transfer.
A Wireless Personal Area Network (WPAN) which
will use Zigbee Specification to transfer recorded
itemized data.
Handheld Device which will be used as buffer to
collect data from meter wirelessly and transfer it to
computer.
9. Project Overview
The design of this project will consist of three stages:-
Meter Reading Retrieval Unit using AVR and Zigbee
Transceiver.
Designing of dedicated Wireless network Protocol
using Zigbee.
Handheld device for collecting reading from Meters
wirelessly.
10. Implementation
First, host (handheld device) sends request for
retrieval of data (meter reading).
Clients (Electric Meter) receives request and sends a
packet containing current reading (payload) with its
client ID (Unique for each electric meter) to host.
Host receives packet, extract payload (reading) and
client ID
This information is stored in handheld device’s
memory in form of database.
11. Block diagram for implementation
Steps of implementation are as shown
12. Digital Energy Meter
The digital energy meter measures AC
power, instantaneous and average, 0–1200 W, as well as
measure AC energy consumption in kilowatt-hours (or
watt-hours).
It provides digital readout of power and energy.
14. Working of Digital Meter
The power-supply subsystem supplies DC power to the
other subsystems.
The microcontroller and A/D subsystem acquire data
and compute power readings that are then displayed
by the LCD subsystem.
The power mode displays the power consumed in
watts. By accumulating power over time, the energy
mode will display watt-hours or kilowatt-hours.
15. Atmel Mega32 Microcontroller
The Atmel AVR ATmega32 is a low-power CMOS 8-bit
microcontroller based on the AVR enhanced RISC
architecture.
By executing powerful instructions in a single clock
cycle, the ATmega32 achieves throughputs
approaching 1 MIPS per MHz allowing the system
designer to optimize power consumption versus
processing speed.
17. General pins in use
VCC Digital supply voltage.
GND Ground.
Port A (PA7..PA0) Port A serves as the analog inputs
to the A/D Converter.
RESET Reset Input
XTAL1 Input to the inverting Oscillator
amplifier and input to the internal
clock operating circuit.
XTAL2 Output from the inverting Oscillator amplifier.
AVCC AVCC is the supply voltage pin for Port A and the
A/D Converter.
AREF AREF is the analog reference pin for the
A/D Converter.
18. Architectural Overview
In order to maximize performance and parallelism, the
AVR uses a Harvard architecture – with separate
memories and buses for program and data.
. The fast-access Register File contains 32 × 8-bit
general purpose working registers with a single clock
cycle access time .
This allows single-cycle Arithmetic Logic Unit (ALU)
operation.
20. USART
The Universal Synchronous and Asynchronous serial
Receiver and Transmitter (USART) is a highly flexible
serial communication device.
Full Duplex Operation (Independent Serial Receive
and Transmit Registers)
Asynchronous or Synchronous Operation
Master or Slave Clocked Synchronous Operation
Framing Error Detection
Noise Filtering Includes False Start Bit Detection and
Digital Low Pass Filter
21. Analog to Digital Converter
The ATmega32 features a 10-bit successive approximation
ADC.
10-bit Resolution
0.5 LSB Integral Non-linearity
±2 LSB Absolute Accuracy
13 μs - 260 μs Conversion Time
Up to 15 kSPS at Maximum Resolution
8 Multiplexed Single Ended Input Channels
7 Differential Input Channels
2 Differential Input Channels with Optional Gain of 10x
and 200x
22. Zigbee
ZigBee is one of the newest technologies enabling
Wireless Personal Area Networks (WPAN).
The specification characterized by low data rates and
very low power consumption is revolutionising home
networking.
ZigBee is an established set of specifications for
wireless personal area networking (WPAN), i.e. digital
radio connections between computers and related
devices.
26. Handheld Device
The handheld will consist of an ARM based device that
will store data collected from all the meters onto a SD
card.
This data will then be transferred on to a computer
using a wired connection.
28. Serial Peripheral Interface Bus
It is a synchronous serial data link standard, named
by Motorola that operates in full duplex mode.
Devices communicate in master/slave mode where the
master device initiates the data frame.
Multiple slave devices are allowed with
individual slave select (chip select) lines.
29. Advantages
can be used in large malls and commercial building
where monitoring is impossible by inspection.
In large area of installation we can easily set it up by
use of amplification circuit on lines.
Using Zigbee interface Power can be saved, as a result
of the short working period, low power consumption
of communication, and standby mode.
Safe house monitoring.
Low power consumption and easy to maintain and
repair.
ZigBee provides a data integrity check and
authentication function, which provides data security
during transmission.