Download Abstract - PG Embedded systems

WIRELESS TRANSFORMER TESTING THROUGH MICROCONTROLLER
AIM:
This project is mainly developed on the basis to help Electricity Board department by
identifying the fault in Transformer (automatically).
PROJECT DESCRIPTION:
There are some possibilities of fault in EB transformer. There is a possibility of increase
in temperature, coolant oil leakage, and short circuit in EB transformer which are all very
harmful to the transformers health. Hence these parameters should be monitored continuously to
avoid those kinds of harmful situations and to product the transformer by which we can save
large amount of money also.
The EB department is a huge network and it has a lot of grids transformers and other
networks connected to it throughout the country, thus making it one of the important sectors for
the country.
And there are many users for this as it is an important resource for everyone in the
country, and the employers are maintaining a huge set of data and electricity and will be
knowing through which the whole grid runs and powers up the country.
So maintaining this whole grid makes a big problem for the employers and they will not
know in which area a fault has occurred whether in the transformer or any other unit, so this
project is mainly designed to control the fault detection of any transformer in any part in the
sector.
Thus making this project an important format of checking the transformers throughout
the country and replacing it if there is a problem in the transformer unit.
WORKING PRINCIPLE:
Our project is designed for monitor the parameters like temperature, oil level and short
circuit for that we are using PIC 16F877A controller. Here controller is used for controlling the
parameters and each and every part of the system. Temperature sensor is used to monitor the
continues change in temperature and oil level sensor is used to find the coolant oil level which
is a precious factor in transformer circuit to reduce the temperature of the transformer whenever
it increases beyond the limit.
Short circuit is another important factor in the transformer system when the short circuit
occurs in the transmission line, it will directly affects the transformer it spoils the whole
transformer system.
Hence we have a separate system for short circuit production. We also have another part
called as motor section which is immersed in coolant oil. The speed of the motor is inversely
proportional to the density of the coolant oil. Whenever the density of the coolant oil increases
the speed of the motor will decrease automatically and vice versa. Thus we can find the density
of the oil according to that we can also find the life of the coolant oil.
This system has an another advantage that is current transformer by using which we can find
the amount of the power consumed by the customer if the amount if power increased our system
automatically cut of the power supply thus we can save the power. These monitored data are
continuously send to the control room though ZIGBEE TRANSCEIVER which reduces the man
power largely.
It has a TRANSCEIVER section. Transmitter section is located in the transformer section
and the receiver section is in the EB office.
So whatever the problem occurred in the Transformer, it will send the message to the
Receiver unit (i.e., EB office).
LCD display is used to display the characters. What is the problem occurred in the
transformer side, it will display. So the user can understand easily. Thus this circuit is mainly
designed to interface the unit with the computer and then to store the data in it.
COMPONENTS USED:
 PIC 16F877A
 TEMPERATURE SENSOR
 OIL LEAKAGE SENSOR
 OIL LEVEL SENSING
 LCD DISPLAY
 BUZZER
 RF COMMUNICATION
Distribution Transformer Block:
Temperature
Sensor - LM 35
Power Supply
Oil Level Sensing
RF Transmitter
433.8MHz
PIC Microcontroller
PIC 16F 877A
Oil Leakage
Sensing
Current
Transformer
Relay Driving
Section
Output Load
2 X 16
LCD Display
Shot Circuit
Hand Hold Meter Block:
RF Receiver
433.8 MHz
Power Supply
PIC Microcontroller
16F 877A
Alert Buzzer
2 X 16
LCD Display
BLOCK DIAGRAM DESCRIPTION:
POWER SUPPLY:
An AC powered unregulated power supply usually uses a transformer to convert
the voltage from the wall outlet (mains) to a different, nowadays usually lower, voltage. If it is
used to produce DC, a rectifier is used to convert alternating voltage to a pulsating direct voltage,
followed by a filter, comprising one or more capacitors, resistors, and sometimes inductors, to
filter out (smooth) most of the pulsation. A small remaining unwanted alternating voltage
component at mains or twice mains power frequency (depending upon whether half- or full-wave
rectification is used)—ripple—is unavoidably superimposed on the direct output voltage.
For purposes such as charging batteries the ripple is not a problem, and the simplest unregulated
mains-powered DC power supply circuit consists of a transformer driving a single diode in series
with a resistor.
PIC 16F877A MICROCONTROLLER:
High Performance RISC CPU:
• Only 35 single word instructions to learn
• All single cycle instructions except for program branches, which are two-cycle
• Operating speed: DC - 20 MHz clock input
DC - 200 ns instruction cycle
• 2K x 14 words of Program Memory, 128 x 8 bytes of Data Memory (RAM)
• Pin out compatible to PIC16C72/72A and PIC16F872
• Interrupt capability
• Eight-level deep hardware stack
• Direct, Indirect and Relative Addressing modes
Peripheral Features:
• High Sink/Source Current: 25 mA
• Timer0: 8-bit timer/counter with 8-bit prescaler
• Timer1: 16-bit timer/counter with prescaler, can be incremented during SLEEP via external
crystal/clock
• Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler
• Capture, Compare, PWM (CCP) module
- Capture is 16-bit, max. resolution is 12.5 ns
- Compare is 16-bit, max. resolution is 200 ns
- PWM max. resolution is 10-bit
• 8-bit, 5-channel analog-to-digital converter
• Synchronous Serial Port (SSP) with SPI™ (Master/Slave) and I2C™ (Slave)
• Brown-out detection circuitry for Brown-out Reset (BOR)
LCD DISPLAY:
A liquid crystal display (LCD) is a thin, flat electronic visual display that uses the light
modulating properties of liquid crystals (LCs). LCDs do not emit light directly. Liquid crystal
displays (LCDs) are a passive display technology. This means they do not emit light; instead,
they use the ambient light in the environment. By manipulating this light, they display images
using very little power. This has made LCDs the preferred technology whenever low power
consumption and compact size are critical. They are used in a wide range of applications,
including computer monitors, television, instrument panels, aircraft cockpit displays, signage,
etc. They are common in consumer devices such as video players, gaming devices, clocks,
watches, calculators, and telephones. LCDs have displaced cathode ray tube (CRT) displays in
most applications. They are usually more compact, lightweight, portable, less expensive, more
reliable, and easier on the eyes.
Pin Information of LCD:
RF TRANSMITTER:
Radio transmitter design is a complex topic which can be broken down into a series of
smaller topics. A radio communication system requires two tuned circuits each at the transmitter
and receiver, all four tuned to the same frequency. The transmitter is an electronic device which,
usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television,
or other telecommunications.
RF RECEIVER:
This compact radio frequency (RF) receiver module is suitable for remote control or
telemetry applications. The double sided circuit board is pre-populated with Surface Mount
Devices (SMD) and is tuned to 433MHz. No module assembly or adjustments are required. RF
receiver module RX433 receives RF control signals from the. RF receiver module RX433 is a
highly sensitive passive design that is easy to implement with a low external parts count.
(Download datasheet with hook-up schematic below)
RF remote receiver module RX433 can also be used with 433MHz RF Transmitter
TX433N for your custom remote control or telemetry requirements. (However, the FCC has
restrictions on the sale of the TX433N transmitter module in the U.S., so we don't have these
transmitters available).
The RF receiver has the same range of RF transmitter; it is a wireless RF receiver which
is of 433.8 MHz and 7v-12v DC operation. And mainly 600ft of receiving.