Power theft detection via plc

Power Theft Detection via PLC

By,
Shashanka B (1RV08EE047)
Ravi S Gokavi (1RV08EE041)
Chandrashekar C (1RV07EE016)

POWER THEFT
 Electrical power by
altering, slowing, resetting, swapping, or disconnecting
an electric meter.
 Theft also may occur by rewiring circuits to avoid an
electric meter, or by tapping into another customer’s
electrical lines.
 The fraudster might use devices to program the theft of
power only during certain periods of the day or week.
 A fraudster may rewire their property to illegally use
power from cheaper sources of power, or from meters
that are billed at lower rates.

To minimize power theft PLC’s can be installed.

PLC (Programmable logic controller)

 It is a digital computer used for automation of
electromechanical process.
 The PLC’s are designed for multiple input and multiple
output.
 Program to control machine operation are typically
stored in non volatile memory.
 It is an example of a hard real time system since
output results must be produced in response to input
conditions within bounded time.

Programming of PLC

 Early PLC’s were programmed by using specific
purpose programming terminals.
 The programs were stored in cassette tape
cartridges.
 Facilities of printing and documentation were very
minimal due to the lack of memory.
 The very old PLC used non-volatile magnetic core
memory.

Continued…..

 Recent PLC’s are programmed using application
software's on personal computers.
 Computer is connected to PLC through RS-232, RS-485
or RS-422.
 The software provides the facilities of debugging and
troubleshooting the PLC software.
 Modern PLC’s use EEPROM or EPROM as a memory.

Oldest PLC by BEDFORD ASSOCIATES

PLC features

 The main difference from other is that PLC’s are
armored for severe conditions and have the facilities
for extensive I/O arrangements.
 It can be connected to sensors, actuators.
 They also read limit switches and analog process
variables.
 They can operate electrical motors, pneumatic or
hydraulic cylinders, magnetic relays etc.

PLC INSTALLATION
Power meters with PLC modules will be installed near the top
of the power polls.
Meters installed in high places will send data of the used
amount to each household through power lines.
Homeowners can then check the amount used on the displays
installed in each house.
This means that the measurement function and the display
function of the meters will be separated.
Power theft is prevented by installing HD-PLC-mounted power
meters on a high position on power polls, while the amount of
power used in each household can still be checked.

Each power meter is connected to an optical fiber
network, and information of the amount used by each
household is sent to the power companies.
If the power companies find that a payment is
delinquent, they can remotely stop the power supply by
controlling the meters through the optical fiber network.
The waste of power can also be reduced, another big
advantage.
Furthermore, wide spread use of the power meters with HD-
PLC modules is expected to reduce regional disparities in
information, or the ‘digital divide’.

Methods Of Illegal Electricity Usage
Using the mechanical objects:
A subscriber can use some mechanical objects to prevent the revolution
of a meter, so that disk speed is reduced and the recorded energy is also
reduced.
Using a fixed magnet:
A subscriber can use a fixed magnet to change the electromagnetic field
of the current coils. As is well known , the recorded energy proportional to
electromagnetic field.
Using the external phase before meter terminals:
This method gives subscribers free energy without any record.
Switching the energy cables at the meter connector box:
In this way ,the current does not pass through the current coil of the
meter, so the meter does not record the energy consumption.

Although all of the methods explained above may be valid for electromechanical
meters, only the last two methods are valid for digital meters.

The components involved in PLC are,

1. Power Line Carrier Unit which provides
signal transmission and reception.
2. There is a Coupler used for “clamping”
around a live wire thus injecting the
communication signals into the power line.
3. PLC modem

The monitoring system mainly has the
following functions

1. Remote meter-reading
2. Data acquisition
3. Thread PLC transmissions are synchronized to the
zero crossing point of the AC power line.

It should be transmitted as close to the zero
crossing point i.e. within 200 μs. Square wave with a
max Delay of 100 μs from the zero crossing point The
maximum delay between signal envelope input and
120KHz output bursts is 50 μs. Therefore, it should be
arranged that outputs to the within 50 μs.

CODE TRANSMISSION

 A Binary 1 is represented by a 1 ms burst of 120 KHz.
 The zero crossing point and a Binary 0 by the absence
of 120 KHz.
 Therefore only the 1 ms "envelope" need be applied
to their inputs.
 These 1 millisecond bursts should actually be
transmitted three times to coincide with the zero
crossing points of all three phases in a three
phase distribution system.

DEFINITION ON AMR
AMR(AUTOMATIC REMOTE READING)

 Automates the process of measurement through digital
communication techniques.
 Bring “intelligence” into the revenue cycle and manage it.
 The revenue cycle includes metering, billing
operating, customer and the services.

ADVANTAGES
1. Smart automated process instead of manual work.
2. Accurate information from the network load to optimise
maintenance and investments.
3. Customized rates and billing dates.
4. Streamlined high bill investigations.
5. Detection of tampering of Meters.
6. Accurate measurement of transmission losses.
7. Better network performance and cost efficiency.
8. Demand and distribution management.
9. More intelligence to business planning.
10. Better company credibility.

Companies manufacturing PLC’s

 VIPA art of Automation
 Unikom-Ug – metering
 Alstom
 ABB utility communications
 ADD group
 Motorola
 Delta PLC

Etc……

Power theft detection via plc

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Power theft detection via plc