– In developing
countries, power theft is one of the most extensive issues which cause not only
economic losses but also uneven supply of electricity. It hampers working of
industries and factories, due to shortage of power supplied to them. It causes deficiency
of power supply to homes. It leads to loss of income by Government as
individual enterprises may option to install their own power generators, increases
corruption in form of inducement and many more. Science and technology with or
its advancement has engrossed human life to a great extend that imagine a world
without this invention is hardly possible, while technology is on their raising
slope we should also note the increasing unethical activities. With technology
view, “power theft” is non ignorable crime that is highly prevalent and at that
time is directly affects the economy of nation. Data collected our Tirunelvile District;
Bhel tricky proves the necessity of this project.
Key word: zero crossing detector, PIC16F886
Our aim of project
is to prevent the power theft by illegal tapping and meter fraud. Our project
also implies the work as voltage stabilizer it feed a constant voltage to the
load. Electric meter can be manipulated, thus causing them to stop, under
register or bypassing the meter. Consumers, who are interfere with electric
meter, efficiently use power without paying for it. This theft or fraud can be dangerous
as well as deceitful. A power regulator is a device which connects in series to
power. Apparently just by keeping the device connected it will immediately
control and stabilize power usages at that instant. This system can claims
savings between 20% and 30% electricity. It is known that the electricity that
comes to our homes will not stable in nature. Our aim of project is to confine
a power theft by implementing a high voltage passing through the transmission
line which will be allocated by a sub-station, by changing a taps of
transformers randomly. Further this high voltage used by consumer through our
system in which we regulate the voltage across the load up to a definite limit.
Those consumer who are operating their electrical devices through illegal
hooking or energy meter bypassing can be absolutely suffer by this high
voltage, which may cause damages to the operating devices.
Fig: Block diagram
of power theft by controlling microcontroller.
diagram shows the operation of power theft prevention by using
PIC16Fmicrocontroller. The microcontroller controls the voltage across load
through giving a firing angle to TRIAC. TRIAC is work as a switch and it
operate when microcontroller gives the firing angle and firing angle pulse.
In our project we
are uses a power electronic device like TRIAC to control the power. Use of
power electronic reduces the mechanical
arcing and fast reaction time. In addition to this we also made a provision for
under/ over voltage protection which don’t have any existing energy meters.
Microcontroller analyze the incoming voltage coming from line with the help of
ADC (Analog to Digital Controller) present inside the microcontroller, is used
to control a positive as well as negative
half cycle of incoming AC for that a firing angle control method is used For controlling
a firing angle of any AC voltage. It is necessary to monitor every +ve / –ve
half cycle, hence a Sine Wave Cycle Monitoring (Zero Crossing Detector) is use
in our project , which inform a controller about start point of every cycle.
Once controller knows the voltage across the load and signals from sine wave
cycle monitor, controller calculate the firing angle and gives firing angle and
firing angle pulse to the AC to AC converter in which TRIAC is used to form
static switch for operation, it can operated on high voltage and high frequency
as compared to mechanical switches, such as relay. The output of AC to AC
converter is further give to reactor which is nothing but a type of single core
step-up transformer. (220v-280v transformer is used in our project), which
gives a 220v output at 140v AC input. The output 220v is further used by
various types of load. The voltage across load is measured by the PIC-microcontroller
with the help of potential transformer (PT). Potential transformer is used to step
down to voltage across the load to be measured and rectified to DC, because
microcontroller can read a voltage up to 5v DC only. In or project we are using
relay for tripping the input voltage in case of very high voltage and low
voltage which is beyond controllable limit. The relay used for 12v and
controller can give maximum of 5v. Hence it is required to amplify the 5v-12v
for used to driver circuit. The microcontroller is used to control the firing
angle of TRIAC to give the angle of triggering.
Block diagram of the proposed system
The function of
A. Full Wave
Rectifier (12VAC to 12VDC): A Full Wave Rectifier is a circuit, which converts
an 12v AC voltage into a pulsating 12V DC voltage using both half cycles of the
applied ac voltage. It uses two diodes of which one conducts during one half
cycle while the other conducts during the other half cycle of the applied.
rectification in proposed system
Regulator (12VDC to 5VDC): A voltage regulator is designed to automatically
maintain a constant voltage level. It is
used to stabilize the DC voltages used by the controller and other elements.
C. A zero crossing
detector: It is used to monitor a sine wave cycle. It is a one type of voltage
comparator, used to detect a sine waveform transition from positive and negative
that coincides when input crosses the zero voltage condition. In alternating
current, the zero-crossing is the instantaneous point at which there is no voltage
present. In a sine wave or other simple waveform, this normally happen twice
during each cycle.
Zero Crossing Detector circuit
c. Driver: A
Microcontroller digital logic output pin supplies only 10mA of current to
external devices such as high-power relays can require less than 100mA and they
need more voltages. In order to control such devices which use high DC current,
a transistor-based driver circuit is used to amplify current to the required
levels. If the voltage and current levels are in moderate range, the transistor
acts like a high-current switch controlled by the lower current digital logic
and driver: An opto-coupler are designed to provide complete electrical
isolation between an input low voltage side ( controller side) and output high
voltage side (TRIAC side) circuits.
E. LCD: LCD
(Liquid Crystal Display) screen is an electronic display module and used to
display the operation of connected devices.
F. TRIAC: These
are Static devices used to switching operation. Static device is such device
which converts one type of energy or energy level into another type of energy
or energy level respectively without any physical movement.
Microcontroller: In our project we are using a PIC microcontroller which has
RISC (restricted Instruction Set Codes) architecture due to which controller
requires only One Clock Cycle to complete a single execution. In our project we
are using a 28 pin microcontroller having 16K/b of FLASH ROM, 1.2K/b of RAM,
and 256 bytes of EEPROM. This controller having a inbuilt 10 Bit ADC which
requires to measure input and output analog voltages. The operating cycle of
PIC is of 200n/s. The output port capability is to deliver 5v/40mA on each port
The main task of
our project is to indicate the power theft, control and stabilize the power via
monitoring through microcontroller. Our project is complete when electricity
supply authority passed the high voltage (220-280) for few minutes, then power
theft will be prevent by stabilizing the voltage through our system. In our project we give 220V-280V, after
completing the operation, the output voltage feed constant (280V) across the
load. The actual purpose of project is to be stabilizing the voltage and
prevent the theft of electricity.
AND FUTURE SCOPE
based device which we design is easy to implement and beneficial for both
energy supply authority and consumer. It also provide additional feature such
as stabilize the voltage, it feed a constant voltage. It also gives the
information of total load used in house on request at any time. The statistical
load used and profile can help consumer manage their energy consumption. This
system is secured and reliable because it can access by automatic operation.
This device has the capability to faced the high voltage and feed the constant
voltage to household appliances. This device help to reduced the theft of power
by implementing a high voltage through our system which stabilize the voltage,
whose consumer used electricity by illegal hooking or bypassing the meter they
will suffer by this high voltage. As this device stabilizes only higher voltage
but by using active reactor in system, we can also maintain the output voltage
if input voltage drop down to 160V. It will completely eliminate the power
theft and will increase revenue for the government and save electricity.