CHAPTER 1

INTRODUCTION

1. 1 GENERAL

Electrical faults seem to be the major reason for industrial disasters in the

country as 56 per cent of incidents are reportedly caused by them. Overheating,

ageing of the material and use of sub-standard quality of electrical gadgets have

been the main factors contributing to the increasing electrical fire accidents in

industries in the past four years. Electrical accidents continue to be a significant

cause of on-the-job death in overall world. In our state also like this injuries

happening frequently. On April 2013, we lost four workmen in Karur district

due to this accident. Wiremen use for their security purpose like cheppals,

wooden ladder, handglows etc,. This is not enough for their security. So we are

introducing an innovative wiremen security system using fingerprint. One of the

main job of wiremen security system is power automatically controlled by

itself. The losses reduced by this method. It is an effective electrical safety

intervention. Actual numbers of electrical injuries can indicate the overall

magnitude of various electrical safety issues in the workplace. However, they

are usually not useful for comparing electrical injury experience among

different industries, or even from year to year in the same industry or group,

because of differences in employment. Rates of injurynormalize the data to

account for differences in exposedpopulations, and so afford a more direct

means to comparethe electrical safety history of disparate groups.

[1]

CHAPTER-2

LITERATURE SURVEY

2.1 Design of super conducting fault current controller

By the advent of the smart Grid and integration of distributed generators,

electrical networks are facing uncountable challenges. The existing protection

schemes that simply limit the fault current to the predetermined set values may

not perform optimally, and even the existing protection coordination schemes

fail and lead to catastrophic failures in the increasingly complex and

unpredictable grid operation. This paper proposes a novel and smart design of

fault current controller constituting a fullbridge thyristor rectifier embedding a

superconducting coil. When a fault occurs and the resulting current through the

superconducting coil exceeds a certain preset value based on the current

operating conditions of the grid to maintain the grid integrity, the magnitude of

the fault current is regulated to a desired value by automatic controlling of the

thyristor. This research also implements a lab-scale Smart FCC with smart

current control capability and demonstrates the desired functionality and

efficacy of design by changing the fault conditions. This proposed Smart FCC

design will make the Smart Power Grid capable of self-healing against current

faults.

2.2 Embedded Control System

The embedded control system consists of a target PC, a DAQ device, and

embedded software for the operation of the algorithm. The DAQ device is

connected to the target PC [11]. Therefore, the target PC can access the

acquired electrical signal through the DAQ device. In addition, the target PC

calculates the line impedance and phase angle according to the embedded

software algorithm.

[2]

In these short circuit tests, the amplitude of the input AC power voltage is 52 V,

and the target current is 60A. Then, the phase angle data table was calculated

to meet the target current condition using there positive circuit simulation.

2.3 Thyristor Control Circuit

To supply the gate pulse corresponding to the phase angle to the thyristor, a

control circuit is required. The circuit is composed of a phase control

IC(TCA785)[12], a BJT to amplify the pulse current, and some passive

elements. The control voltage that was calculated by the algorithm is provided

to the phase control IC. Then, the phase control IC outputs a gate pulse

corresponding to that control voltage. Fig.shows the circuit diagram of the

thyristor control circuit.

[3]

2.4 Superconducting Coil

To prevent adrastic increase in the fault current in the first halfcycle, a

large inductor is required in the FCC system. However, a large inductor

fabricated by the normal conductor leads to severe joule heating and avoltage

drop. To solve this problem, a superconducting coil that can prevent a sudden

increase in the fault current without joule heating loss is required. In this

research, a high temperature superconducting (HTS) coil has been employed of

unction’s large inductor. The superconducting coil consist of two pancake HTS

coils connected in parallel, and each pancake coil is wound with SuNAM

CCtapethatis4mmwide and that has a self field critical current of

about130A[13].The Fabricated Pancake coils are stacked together, and the

magnetic field generated by each coil is mutually linked. By doing this, the

total coil inductance can be treated as a single coil inductance even though the

two coils are connected in parallel. The inner radius of the pancake coil bobbin

is 54mm, and the number of turns is 50. The total inductance of the HTS coil

is about 0.1mH. Fig.4 shows the fabricated super conducting coil.

In this paper, Smart FCC employing a super conducting coil is proposed

which is an overland smart method for fault current control in Grid. The Smart

FCC can automatically detect a fault, calculate the line impedance, and

determine the proper phase angle. Through these processes, the Smart FCC can

control the fault current quickly and effectively. It is observed from the

experimental results that the fault current is reduced to the target value by

means of the phase angle calculated by the embedded control system.

[4]

2.5 Circuit Breaker Design and Operation to Improve Safety

Traditional “above- ground” applications of circuit breakers for over current

protection in industry are generally well understood. Defined design and test

standards, which vary some what across the globe, provide a frame work for

users of these devices to assure that the yare not misapplied. Attention to detail

in circuit breaker maintenance generally assures that these devices will operate

reliability and safety across the industry. However, when circuit breakers are

applied in underground mining applications, traditional design and test

standards give way to in-country mining safety authorities who typically dictate

requirements in these special applications. Because of this, ratings and test

requirements for low-voltage molded-case circuit breakers, low-voltage power

circuit breakers, medium-voltage vacuum and medium voltage sulphur hexa

fluoride(SF6) circuit breakers in underground mining are typically different.

In this environment, the user must be aware of issues specific to the application

to assure that these devices operate such that they assure miner safety and

operation reliability. This paper will discuss specific circuit breaker

applications in underground mining and recommend methods to maximize the

effectiveness of these protective devices in this environment.

[5]

2.6 Special circuit breaker applications for mining

Circuit breakers are used in underground mining equipment including the

machines used for mining itself, such as shears and continuous miners, and also

in power centers that typically feed electrical power to the underground mining

equipment. It is interesting that the circuit breaker components themselves are

not necessarily manufactured or tested to traditional standards that otherwise

apply for assemblies used in industry above ground. One variable is the

operating voltage of the device itself. Other issues around necessary fault

current ratings, operating conditions, circuit ground(earth)protection, and a

harsh environmental need to be considered.

. Low-voltage metal-enclosed control gear manufactured to IEC Standard 61439.

[6]

A typical power center applied in underground mining applications. The

power center assembly takes on several different forms and ratings dependent

upon where the underground mine resides across the world. The underground

power center is an engineered assembly designed to transform and distribute

electrical power brought to the underground from the surface. Typically, this

assembly includes a medium- voltage incoming circuit breaker or switch with

current-limiting fuse. This device protects a close-coupled dry- type vacuum

pressure impregnated power transformer used to convert the medium voltage to

a lower distribution voltage. The transformer then feeds low-voltage circuit

breakers that, in turn, feed and protect external underground mining loads

connected to the power center via extended trailing cables. These conductors

can often span thousands of feet(meters)in length.

The first not able difference in this assembly versus those

showninFigs.1and2 is the low-profile design. Where as the low-voltage metal-

enclosed ANSI/NEMA switch gear assemblies are typically2286mm(90in)

high and low-voltage metal- enclosed IEC control gear assemblies are typically

2000mm (78.75in) high, underground power centers are typically less than

half this height in order to satisfy clearance requirements in underground

mining applications. Because the application involves long lengths of

trailing cables, the issue of voltage drop on generally soft power systems

dictates that the application voltage is generally higher. In the U.S., it is not

unusual for secondary distribution voltages to be three-phase 1000 V ac, while

in China or Australia, for instance, operating voltages can be up to 1240 Vac.

Most importantly, the design codes and standards for this assembly are not

dictated by ANSI/NEMA or IEC standards. Instead, the in-country local

mining authority generally review sand approves these assemblies for

application in underground mines.

[7]

In the U.S., this authority is the U.S. government’s Mine Safety and

Health Administration(MSHA). MSHA dictates written regulations, and in the

event of a mining accident or fatality, they are the authority having jurisdiction

who will investigate the incident and issue other penalties by law. In Australia,

mines safety and inspection regulations are dictated by the Australian

government.

A.MCCBs in Mining

Today’s modern molded-case circuit breakers(MCCBs) are applied

throughout most, if not all, industries, offering a safe and economic means of

connecting and disconnecting loads from the electrical source and providing

both overload and short-circuit over current protection. Although there are

many types of MCCBs, all are comprised of five major components including

them olded case or frame, an operating mechanism, arc extinguishers, contacts,

and trip components. A cut away view of a typical MCCB is

showninFig.4hereinafter.

Unique issues exist in identifying when an MCCB should be considered as a

candidate to be replaced. By nature of the component itself, manufacturers of

these products assemble, calibrate, test, and, then, many times, seal the molded

cases of these devices. There are typically no internal serviceable parts, and

breaking the factory seal generally results in jeopardizing the manufacturer’s

warranty. Because of issues inherent to the product design, historically, the

maintenance of MCCBs by the end user has been limited to mechanical

mounting, electrical wiring, and manual operation of the mechanism. Although

beyond the scope of this paper, further information on the maintenance of

MCCBs can be found in[7].

[8]

CHAPTER 3

SYSTEM ANALYSIS

3.1 EXISTING SYSTEM

All linemen, especially those who deal with live electrical apparatus,

use personal protective equipment(PPE) as protection against inadvertent

contact. This includes rubber gloves, rubber sleeves, bucket liners and

protective blankets. When working with energized power lines, linemen must

use protection to eliminate any contact with the energized line.

The requirements for PPEs and associated permissible voltage depends

on applicable regulations in jurisdiction as well as company policy. Voltages

higher than those that can be worked using gloves are worked with special

sticks knows as hot-line tools or hot sticks, with which power lines can be

handled from a distance. Linemen must also wear special rubber insulating gear

when working with live wires to protect against any accidental contact with the

wire.

The buckets linemen sometimes work from are also insulated with fiber

glass. During the work these equipments if failure then accidents may happen.

These kind of resistors not provide proper security to our wiremen. If more

current generated from transformer these kind of existing system not enough to

secure them. In order to provide the security to the wireman at the workplace

we are introducing our concept to do make wellbeing.

[9]

3.2 DRAWBACKS

The flash injured an employee, damaged equipment and caused a

power outage affecting the surrounding area.

Lack of awareness and safety measures claimed the life of line

man. For example, In Nagpur, a 30-year-old woman who

was electrocuted while working with her husband at Navkanya

Nagar in Kalama on Sunday The couple was digging a well when

the incident took place.

Another example for electrocution is a lineman with the electricity

department, Krishna Madhu Velip,35,was electrocuted after

coming into contact with a live high tension wire at Costae ,Kalay,

on Tuesday morning. Velip was a resident of Barcem, Quepem.

These accidents are happened due to the usage of above mentioned

existing system.

[10]

3.3 PROPOSED SYSTEM

In order to provide the security to the wireman at the workplace we are

introducing our concept to do make wellbeing. To reduce the electrical injuries

we are introducing the Matrix keypad for providing security to wiremen. By

providing the 4-digit personal code for each wiremen we can control the power

supply. If the entered code is wrong then it will intimate to the lineman using

buzzer and also by the LCD.

We will place this control board on the transformer.After finishing their

work they must enter the personal code to the matrix keypad then power

supply is automatically ON. The control of this project is fully based on the PIC

microcontroller. This is main advantage of our project.

To Isolate controlling circuit from controlled circuit and to control high

voltage system with low voltage and then control high current system with low

current by using relay. Basically we are using EMR relay. The EMR relay act as

a switch to ON and OFF the current supply to transformer.

[11]

3.4 ADVANTAGES OF PROPOSED SYSTEM

The linemen no need to bring any safety equipments with themselves.

After providing the wireman secrete code to the keypad matrix the power

is automatically ON and OFF.

Here the loss of electrical injuries will be reduced.

It is more productive and secured method.

CHAPTER-4

[12]

SYSTEM SPECIFICATION

4.1 TOOLS USED:

• PIC Microcontroller-PIC 16F 887

• The ac input is 240V rms, 50Hz mains supply.

• LCD-2x16 LCD

• Matrix Keypad

• Relay- EMRs

4.2 BLOCK DIAGRAM:

4.3 CIRCUIT DIAGRAM

[13]

Matrix keypad

Power supply PIC Microcontroller 16F 887

LCD Display

Relay

Lamp 1 Lamp 2

[14]

4.4 PIC 16F887 MICROCONTROLLER:

High-Performance RISC CPU:

Only 35 Instructions to Learn:

All single-cycle instructions except branches

Operating Speed:

DC – 20 MHz oscillator/clock input

DC – 200 ns instruction cycle

Interrupt Capability

8-Level Deep Hardware Stack

Direct, Indirect and Relative Addressing modes

Special Microcontroller Features:

Precision Internal Oscillator:

Factory calibrated to ±1%

Software selectable frequency range of

8 MHz to 31 kHz

Software tunable

Two-Speed Start-up mode

Crystal fail detect for critical applications

Clock mode switching during operation for power savings

Power-Saving Sleep mode

Wide Operating Voltage Range (2.0V-5.5V)

Industrial and Extended Temperature Range

Power-on Reset (POR)

Power-up Timer (PWRT) and Oscillator Start-up Timer (OST)

Brown-out Reset (BOR) with Software Control Option

[15]

Enhanced Low-Current Watchdog Timer (WDT) with On-Chip Oscillator

(software selectable nominal 268 seconds with full prescaler) with

software enable

Multiplexed Master Clear with Pull-up/Input Pin

Programmable Code Protection

High Endurance Flash/EEPROM Cell:

100,000 write Flash endurance

1,000,000 write EEPROM endurance

Flash/Data EEPROM retention: > 40 years

Program Memory Read/Write during run time

In-Circuit Debugger (on board)

Low-Power Features:

Standby Current:

50 nA @ 2.0V, typical

Operating Current:

11μA @ 32 kHz, 2.0V, typical

220μA @ 4 MHz, 2.0V, typical

Watchdog Timer Current:

1μA @ 2.0V, typical

4.5POWER SUPPLY SYSTEM

A power supply is a device that supplies electrical energy to one or more

electric loads. The term is most commonly applied to devices that convert one

form of electrical energy to another, though it may also refer to devices that

convert another form of energy (e.g., mechanical, chemical, solar) to electrical

energy. A regulated power supply is one that controls the output voltage or

current to a specific value; the controlled value is held nearly constant despite

variations in either load current or the voltage supplied by the power supply's

[16]

energy source. Every power supply must obtain the energy it supplies to its

load, as well as any energy it consumes while performing that task, from an

energy source. A power supply may be implemented as a discrete, stand-alone

device or as an integral device that is hardwired to its load. In the latter case, for

example, low voltage DC power supplies are commonly integrated with their

loads in devices such as computers and household electronics.

Mains input aspects

Usually, the ac input is 240V rms, 50Hz mains supply.

Take extra care when handling mains powered equipment, make sure of

your safety when constructing and testing.

PLUS make sure that adequate insulation and construction techniques are

employed in the unit.

Mains powered equipment must be properly protected by a fuse and

double pole power switch.

[17]

The mains powered equipment container (box) must be earthed if metallic

or double insulation techniques employed to provide input to output

isolation.

A lot of consumer electronic units (TV, DVD players and

the like) utilise double insulation techniques, so their mains

input power lead only contains Live and Neutral wires,

rather than also including an earth wire as well.

Double insulation techniques present at least two ‘high voltage’

insulation barriers between the mains input circuitry and the system being

powered. For example, the mains transformer has its primary (high

voltage) winding on one bobbin and its secondary winding an a separate

bobbin. Thus, if the primary winding burns up, the mains voltage cannot

reach the ‘secondary side’.

[18]

Transformer Rectifier Filter IC regulator Load

DESCRIPTION

The operation of power supply circuits built using filters, rectifiers, and then

voltage regulators. Starting with an ac voltage, a steady dc voltage is obtained

by rectifying the ac voltage, then filtering to a dc level, and finally, regulating to

obtain a desired fixed dc voltage. The regulation is usually obtained from an IC

voltage regulator unit, which takes a dc voltage and provides a somewhat lower

dc voltage, which remains the same even if the input dc voltage varies, or the

output load connected to the dc voltage changes.

A block diagram containing the parts of a typical power supply and the

voltage at various points in the unit is shown. The ac voltage, typically 120 V

rms, is connected to a transformer, which steps that ac voltage down to the level

for the desired dc output. A diode rectifier then provides a full-wave rectified

voltage that is initially filtered by a simple capacitor filter to produce a dc

voltage. This resulting dc voltage usually has some ripple or ac voltage

variation. A regulator circuit can use this dc input to provide a dc voltage that

not only has much less ripple voltage but also remains the same dc value even if

the input dc voltage varies somewhat, or the load connected to the output dc

voltage changes. This voltage regulation is usually obtained using one of a

number of popular voltage regulator IC units.

[19]

IN OUT 7805 GND

4.5.1 VOLTAGE REGULATORS

Voltage regulators comprise a class of widely used ICs. Regulator IC

units contain the circuitry for reference source, comparator amplifier, control

device, and overload protection all in a single IC. Although the internal

construction of the IC is somewhat different from that described for discrete

voltage regulator circuits, the external operation is much the same. IC units

provide regulation of either a fixed positive voltage, a fixed negative voltage, or

an adjustably set voltage.

A power supply can be built using a transformer connected to the ac

supply line to step the ac voltage to desired amplitude, then rectifying that ac

voltage, filtering with a capacitor and RC filter, if desired, and finally regulating

the dc voltage using an IC regulator. The regulators can be selected for

operation with load currents from hundreds of milli amperes to tens of amperes,

corresponding to power ratings from mill watts to tens of watts.

4.5.2 THREE-TERMINAL VOLTAGE REGULATORS:

FIXED VOLTAGE REGULATOR

Fig shows the basic connection of a three-terminal voltage regulator IC to

a load. The fixed voltage regulator has an unregulated dc input voltage, Vi,

applied to one input terminal, a regulated output dc voltage, Vo, from a second

terminal, with the third terminal connected to ground. For a selected regulator,

IC device specifications list a voltage range over which the input voltage can

vary to maintain a regulated output voltage over a range of load current.

[20]

The specifications also list the amount of output voltage change resulting

from a change in load current (load regulation) or in input voltage (line

regulation).

[21]

Primary Side

Usually single 240V winding or two 120V windings. Might have tappings to

allow operation from other supplies such as 200V, 220V, 240V, 100V, 110V

etc. These multi tapped transformers are usually fitted to test equipment that

could be used all over the world.

Secondary Side

Efficiency usually ~90% for small (<20VA) units, rising to 95% for larger

(~100 to 200VA) units.

MAINS transformers – ratings

Transformers are rated in VA – Volt Amps - with respect to their outputs

A 20VA transformer with a 10V secondary will provide 2A (10V x 2A =

20VA)

A 45VA transformer with a 15V secondary will provide 3A (15V x 3A =

45VA)

A 60VA transformer with two 20V secondary windings will provide 1.5A from

each secondary winding (20V x 1.5A x 2 = 60VA)

The power rating of a transformer is directly related to the cross sectional area

of its magnetic circuit – for a conventional E I transformer this is the cross

sectional area of its central limb (or twice the CSA of one side limb)

Rule of Thumb, VA rating = (CSA x 5.6)2 where CSA is measured in square

inches

So transformer with centre limb 1” wide and laminations 1.2” deep is rated to

(1” x 1.2” x 5.6)2 = 6.722 = 45VA

[22]

AC rectification

This full wave rectification arrangement only has one diode drop in the dc

path, but requires a centre tapped (or dual windings) secondary on the

transformer. More efficient on low voltage supplies because the diode drop

represents a significant loss at low voltage (despite additional transformer

losses). 2V drop (2 diodes) at 10V is 20% loss, whilst 1V drop (1 diode) at 10V

is 10% loss

The Smoothing Capacitor

The output from the transformer and rectifiers the sin waveform. The

smoothing capacitor ‘fills in’ the low voltage portions, so reducing the ripple

voltage amplitude. The larger the capacitor (for a given load), the smaller the

ripple voltage, but the higher the peak current through the rectifiers.

[23]

The Smoothing Capacitor

Close approximation calculations;

C x E = I x t where C is the capacitance in uF

E is the peak to peak ripple in Volts

I is the full load current in mA

t is the diode conduction time in ms, ~ 9ms @ 50Hz

With a 20Vrms output from the transformer the maximum voltage will be about

(20V x 1.414) less 2 diode drops, = 28.28V – 1.4V = 26.88V.

The minimum output (at full load) will be (28.28V x 0.9) – 2V = 23.4V

With a 4700uF smoothing capacitor the peak to peak ripple will be

(I x t)/C = (2000mA x 9ms)/4700uF = 3.83V this is the peak to peak ripple.

i.e. at full load the minimum voltage will be 23.4V – 3.83V = 19.5V.

[24]

4.6 LCD DISPLAY:

LCD is mainly used for display the information. Here we are using 2x16

LCD. Operation of the LCD is

The declining prices of LCDs.

The ability to display numbers, characters, and graphics. This is in

contrast to LEDs, which are limited to numbers and characters.

Incorporation of a refreshing controller into the LCD, thereby relieving

the CPU of the task of refreshing the LCD. In contrast, the LED must be

refreshed by the CPU to keep displaying the data.

Ease of programming for characters and graphics.

4.6.1 LCD pin descriptions

Vcc, Vss, and Vee:

While Vcc and Vss provide +5V and ground, respectively, Vee is used for

controlling LCD contrast.

RS, register select:

There are two very important registers inside the LCD. The RS pin is

used for their selection as follows. If RS=0 the instruction command code

register is selected, allowing the user to send a command such as clear display,

cursor at home, etc. if RS=1d the data register is selected, allowing the user to

send data to be displayed on the LCD.

[25]

R/W, read or write:

R/W input allows the user to write information to the LCD or read

information from it. R/W =1 when reading; R/W=0 when writing.

E, enable:

The enable pin is used b y the LCD to latch information presented to its

data pins. When data is supplied to data pins, high-to-low pulses must be

applied to this pin in order for the LCD to latch in the present at the data pins.

This pulse is a minimum of 450 ns wide.

D0 – D7:

The 8 bit data pins, d0 – d7, are used to send information to the LCD or

read the contents of the LCD’s internal registers.

A liquid crystal display (LCD) is a thin, flat electronic visual, 2*16

matrix 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.

[26]

Pin Information of LCD:

4.6.2 Algorithm to send data to LCD:

1.Make R/W low

2.Make RS=0 ;if data byte is command RS=1 ;if data byte is data (ASCII value)

3.Place data byte on data register

4.Pulse E (HIGH to LOW)

5.Repeat the steps to send another data byte

[27]

4.6.3 LCD Initialization:

Working of LCD depend on the how the LCD is initialized. We have to

send few command bytes to initialize the lcd. Simple steps to initialize the LCD.

1. Specify function set:

Send 38H for 8-bit,double line and 5x7 dot character format.

2. Display On-Off control:

Send 0FH for display and blink cursor on.

3. Entry mode set:

Send 06H for cursor in increment position and shift is invisible.

4. Clear display:

Send 01H to clear display and return cursor to home position.

Addresses of cursor position for 16x2 LCD:

line1 80H 81H 82H 83H 84H 85H 86H 87H 88H 89H 8AH

8BH 8CH 8DH 8EH 8FH

line2 C0H C1H C2H C3H C4H C5H C6H C7H C8H C9H CAH

CBH CCH CDH CEH CFH

[28]

4.6.4 16 x 2 Character LCD

FEATURES:

5 x 8 dots with cursor

Built-in controller (KS 0066 or Equivalent)

+ 5V power supply (Also available for + 3V)

1/16 duty cycle

B/L to be driven by pin 1, pin 2 or pin 15, pin 16 or A.K (LED)

N.V. optional for + 3V power supply

4.7 MATRIX KEYPAD

The Keyboard

It is an input device. Its design came from typewriters that did not use

electricity. A person can type a document, access menus, play games and

perform variety of other tasks. Keys, called Keycaps are the same size and

shape from keyboard to keyboard. These are also placed at the similar

distance from one another in a similar pattern.

Matrix Keypad

Matrix Keypad switches are widely used as digital input devices.

Normally one switch requires one digital I/P pin of a microcontroller, to

interface a matrix of such switches (say a 16 digit keypad), assigning a digital

I/O pin for each key its not possible. To minimize the required number of digital

I/O pins of microcontroller. A very popular method is a keypad matrix where

the keys are arranged into rows and columns so that a 4×4 (16) switches can be

interfaced to a microcontroller using only 4+4 = 8 I/O pins.

[29]

4 x 4 matrix keypad organized in the row and column format

Four columns are connected to the lower half of PORTB (RB0-RB3)

Four rows are connected to upper half of PORTB (RB4-RB7)

When a key is pressed, it makes a contact with the corresponding row

and column

Matrix Keypad Basic Connection

[30]

The rows R0 to R3 are connected to Input lines of Microcontroller. The i/o pins

where they are connected are made Input. This is done by setting the proper in

AVR and TRIS Register in PIC. The columns C0 to C3 are also connected to

MCUs i/o line. These are kept at High Impedance State (AKA input), in high z

state (z= impedance) state these pins are neither HIGH nor LOW they are in

TRISTATE. And in their PORT value we set them all as low, so as soon as we

change their DDR bit to 1 they become output with value LOW.

4.7.1 MATRIX KEYPAD BASIC CONNECTION

[31]

MATRIX KEYPAD 4*3:

DESCRIPTION:

Keypad is an input device which gives the input to other devices depends

upon its matrix ranges. It is classified into 2 types that is 4*4 matrix keypad and

3*4 matrix keypad. The 4*4 matrix keypad have 16 keys and 3*4 matrix keypad

have 12 switches. If we press any key that corresponding row an column was

energized that output is given to other devices. For example if press the first key

D0 and D3 is energized and generate high pulse. This high pulse is given to

other devices.

The rows R0 to R3 are connected to Input lines of Microcontroller. The

i/o pins where they are connected are made Input. This is done by setting the

proper in AVR and TRIS Register in PIC. The columns C0 to C3 are also

[32]

connected to MCUs i/o line. These are kept at High Impedance State (AKA

input), in high z state (z= impedance) state these pins are neither HIGH nor

LOW they are in TRISTATE. And in their PORT value we set them all as low,

so as soon as we change their DDR bit to 1 they become output with value

LOW.

Software

To recognize and encode the key pressed

Set all the columns High by sending ones

Check for any key pressed (non-zero)

Set one column High at a time

Check all the rows in that column

Once a key is identified

Encode based on its position in the column

Time Multiplex Scanning Technique

Codes of the numbers to be displayed are stored in data registers in

sequence

The program gets the codes from the data registers by using the

pointer (FSR0) and sends them out to the LED segments through

PORTB

One display at a time is turned on by sending logic 1 to the

corresponding transistor connected to PORTC

After an appropriate delay, the first display is turned off and the next

display is turned on

Turning displays on/off is repeated in sequence

Problem statement

[33]

Interface four common cathode seven-segment displays to PORTB and

PORTC using the time multiplex scanning technique.

Write instructions to display a four-digit number stored in data registers.

Time Multiplex Scanning

Hardware

Eight data lines of PORTB are connected to the anodes of each display

Each cathode is connected to PORTC (RC3-RC0) through a transistor

Transistors (and LEDs) can be turned on by sending logic 1

Each display is turned on and off in a sequence to display a digit

[34]

Operation:

The keyboard controller detects the keystroke.

The controller places a scan code in the keyboard buffer, indicating

which key was pressed.

The keyboard sends the computer an interrupt request, telling the CPU to

accept the keystroke

4.8 RELAY:

4.8.1 Relay Purpose:

Isolate controlling circuit from controlled circuit.

Control high voltage system with low voltage.

Control high current system with low current.

Logic Functions

4.8.2 Relay characteristics

Electromagnetic Relays (EMRs)

EMRs consist of an input coil that's wound to accept a

particular voltage signal, plus a set of one or more contacts that

rely on an armature (or lever) activated by the energized coil to

open or close an electrical circuit.

Solid-state Relays (SSRs)

SSRs use semiconductor output instead of mechanical

contacts to switch the circuit. The output device is optically-

coupled to an LED light source inside the relay. The relay is turned

on by energizing this LED, usually with low-voltage DC power.

Microprocessor Based Relays

[35]

Use microprocessor for switching mechanism. Commonly

used in power system monitoring and protection.

4.8.3 Working Principle:

All relays contain a sensing unit, the electric coil, which is powered by

AC or DC current. When the applied current or voltage exceeds a threshold

value, the coil activates the armature, which operates either to close the open

contacts or to open the closed contacts. When a power is supplied to the coil, it

generates a magnetic force that actuates the switch mechanism. The magnetic

force is, in effect, relaying the action from one circuit to another. The first

circuit is called the control circuit; the second is called the load circuit.

[36]

4.8.4 ELECTROMAGNETIC RELAY

An electromagnetic relay is a type of electrical switch controlled by an

electromagnet. The electromagnetic relay is used in a variety of applications,

including alarms and sensors, signal switching, and the detection and control of

faults on electrical distribution lines. The electromagnetic relay was invented in

1835, and its straightforward function has not changed much since. Consumers

interact with the electromagnetic relay in a variety of forms daily, from timed

office lights to test buttons and other quality control devices.

The core of the electromagnetic relay, naturally, is an electromagnet, formed by

winding a coil around an iron core. When the coil is energized by passing

current through it, the core in turn becomes magnetized, attracting a pivoting

iron armature. As the armature pivots, it operates one or more sets of contacts,

thus affecting the circuit. When the magnetic charge is lost, the armature and

contacts are released. Demagnetization can cause a leap of voltage across the

coil, damaging other components of the device when turned off. Therefore, the

electromagnetic relay usually makes use of a diode to restrict the flow of the

charge, with the cathode connected at the most positive end of the coil.

Contacts on an electromagnetic relay can take three forms. Normally opened

contacts connect the circuit when the device is activated and disconnect it when

the device is not active, like a light switch.

Normally closed contacts disconnect the circuit when the relay is magnetized,

and a change-over incorporates one of each type of contact. The configuration

of the contacts is dependant upon the intended application of the device.

[37]

The electromagnetic relay is capable of controlling an output of higher power

than the input, and it is often used as a buffer to isolate circuits of varying

energy potentials as a result. When a low current is applied to the

electromagnet, throwing the switch, the device is capable of allowing a higher

current to flow through it.

This is advantageous in some applications, such as tripping alarms and other

safety devices, because a safer low current can be used to activate an application

requiring more energy.

DESCRIPTION:

Relays are electrical switches that open or close another circuit under certain

conditions.12V supply voltage is given to the circuit to switch ON the relay.

Relay circuit have transistor, diode, LED, and electromagnetic coil.

When relay is connected to PIC Microcontroller, 5v is passed to base of the

transistor but transistor has 0.7v only so resister is connected to drop the excess

voltage. Transistor output is give to electromagnetic coil after that it is

energised so emf is produced. This emf closes the second switch and output is

given to load. Diode is connected across the collector terminal of the transistor

and supply terminal it is used to block the flow of emf to supply terminal.

[38]

4.9 PIN DIAGRAM:

4.9.1 Peripheral Features:

24/35 I/O Pins with Individual Direction Control:

High current source/sink for direct LED drive

Interrupt-on-Change pin

Individually programmable weak pull-ups

Ultra Low-Power Wake-up (ULPWU)

Analog Comparator Module with:

Two analog comparators

Programmable on-chip voltage reference

(CVREF) module (% of VDD)

[39]

Fixed voltage reference (0.6V)

Comparator inputs and outputs externally accessible

SR Latch mode

External Timer1 Gate (count enable)

A/D Converter:

10-bit resolution and 11/14 channels

Timer0: 8-bit Timer/Counter with 8-bit Programmable Prescaler

Enhanced Timer1:

16-bit timer/counter with prescaler

External Gate Input mode

Dedicated low-power 32 kHz oscillator

Timer2: 8-bit Timer/Counter with 8-bit Period Register, Prescaler and

Postscaler

Enhanced Capture, Compare, PWM+ Module:

16-bit Capture, max. resolution 12.5 ns

Compare, max. resolution 200 ns

10-bit PWM with 1, 2 or 4 output channels, programmable

“dead time”, max. frequency 20 Hz

PWM output steering control

Capture, Compare, PWM Module:

16-bit Capture, max. resolution 12.5 ns

16-bit Compare, max. resolution 200 ns

10-bit PWM, max. frequency 20 kHz

Enhanced USART Module:

Supports RS-485, RS-232, and LIN 2.0

Auto-Baud Detect

Auto-Wake-Up on Start bit

In-Circuit Serial Programming TM (ICSPTM) via Two Pins

[40]

Master Synchronous Serial Port (MSSP) Module supporting 3-wire SPI

(all 4 modes) and I2C™ Master and Slave Modes with I2C Address

Mask

4.9.2 DESCRIPTION:

The PIC16F887 having 40pins and 5 ports. In this PIC microcontroller

the first pin is connected with the master clear circuit, it is used for the clear

purpose. For this circuit we will provide +5v supply. For this project we won’t

use port A and port E. 11th and 12th pin for the purpose of VSS and VDD. 13th

and 14th pin connected with the crystal oscillator. For PIC16F887 we can use

4MHz to 20MHz crystal oscillator frequency here we are using 4MHz. It will

provide clock pulse for digital circuit. In port C 17th pin is connected with

buzzer circuit. In D port 19,20,21,27,28,29,30 pins are connected with the LCD.

For LCD we will provide +5v supply.

[41]

For RF communication TX and RX C port 25th and 26th pins are used.

For RF we will provide +5v supply. In power supply circuit first the step down

transformer will provide 12v AC supply. Then this alternating current converted

into direct current with the help of bridge rectifier. At last with the help of

particular rectified IC we can get particular voltage level.

I/O PORTS

There are as many as thirty-five general purpose I/O pins available.

Depending on which peripherals are enabled, some or all of the pins may not be

available as general purpose I/O. In general, when a peripheral is enabled, the

associated pin may not be used as a general purpose I/O pin.

OSCILLATOR MODULE (WITH FAIL-SAFE CLOCK MONITOR)

The oscillator module has a wide variety of clock sources and selection

features that allow it to be used in a wide range of applications while

maximizing performance and minimizing power consumption. Clock sources

can be configured from external oscillators, quartz crystal resonators, ceramic

resonators and Resistor-Capacitor (RC) circuits.

In addition, the system clock source can be configured from one of two

internal oscillators, with a choice of speeds selectable via software. Additional

clock features include:

Selectable system clock source between external or internal via

software.

Two-Speed Start-up mode, which minimizes latency between

external oscillator start-up and code execution.

Fail-Safe Clock Monitor (FSCM) designed to detect a failure of the

external clock source (LP,XT, HS, EC or RC modes) and switch

automatically to the internal oscillator.

[42]

TIMER0 MODULE

The Timer0 module is an 8-bit timer/counter with the following features:

8-bit timer/counter register (TMR0)

8-bit prescaler (shared with Watchdog Timer)

Programmable internal or external clock source

Programmable external clock edge selection

Interrupt on overflow

TIMER1 MODULE WITH GATE CONTROL

The Timer1 module is a 16-bit timer/counter with the following features:

16-bit timer/counter register pair (TMR1H:TMR1L)

Programmable internal or external clock source

3-bit prescaler

Optional LP oscillator

Synchronous or asynchronous operation

Timer1 gate (count enable) via comparator or T1G pin

Interrupt on overflow

Wake-up on overflow (external clock, Asynchronous mode only)

Time base for the Capture/Compare function

Special Event Trigger (with ECCP)

Comparator output synchronization to Timer1 clock

TIMER2 MODULE

The Timer2 module is an eight-bit timer with the following features:

8-bit timer register (TMR2)

8-bit period register (PR2)

Interrupt on TMR2 match with PR2

Software programmable prescaler (1:1, 1:4, 1:16)

Software programmable postscaler (1:1 to 1:16)

[43]

ANALOG-TO-DIGITAL CONVERTER (ADC) MODULE

The Analog-to-Digital Converter (ADC) allows conversion of an analog

input signal to a 10-bit binary representation of that signal. This device uses

analog inputs, which are multiplexed into a single sample and hold circuit. The

output of the sample and hold is connected to the input of the converter. The

converter generates a 10-bit binary result via successive approximation and

stores the conversion result into the ADC result registers (ADRESL and

ADRESH). The ADC voltage reference is software selectable to be either

internally generated or externally supplied. The ADC can generate an interrupt

upon completion of a conversion. This interrupt can be used to wake-up the

device from Sleep.

Enhanced Capture/Compare/PWM (CCP1)

The Enhanced Capture/Compare/PWM module is a peripheral which

allows the user to time and control different events. In Capture mode, the

peripheral allows the timing of the duration of an event. The Compare mode

allows the user to trigger an external event when a predetermined amount of

time has expired. The PWM mode can generate a Pulse-Width Modulated signal

of varying frequency and duty cycle.

ENHANCED UNIVERSAL SYNCHRONOUS ASYNCHRONOUS

RECEIVER TRANSMITTER (EUSART)

The Enhanced Universal Synchronous Asynchronous Receiver

Transmitter (EUSART) module is a serial I/O communications peripheral. It

contains all the clock generators, shift registers and data buffers necessary to

perform an input or output serial data transfer independent of device program

execution. The EUSART, also known as a Serial Communications Interface

[44]

(SCI), can be configured as a full-duplex asynchronous system or half-duplex

synchronous system. Full-Duplex mode is useful for communications with

peripheral systems, such as CRT terminals and personal computers. Half-

Duplex Synchronous mode is intended for communications with peripheral

devices, such as A/D or D/A integrated circuits, serial EEPROMs or other

microcontrollers. These devices typically do not have internal clocks for baud

rate generation and require the external clock signal provided by a master

synchronous device.

MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE

The Master Synchronous Serial Port (MSSP) module is a serial interface useful

for communicating with other peripheral or microcontroller devices. These

peripheral devices may be Serial EEPROMs, shift registers, display drivers,

A/D converters, etc. The MSSP module can operate in one of two modes:

Serial Peripheral Interface (SPI)

Inter-Integrated Circuit TM (I2CTM)

Full Master mode

Slave mode (with general address call).

The I2C interface supports the following modes in hardware:

Master mode

Multi-Master mode

Slave mode

[45]

CHAPTER-5

CONCLUSION AND FUTURE ENHANCEMENT

5.1CONCLUSION

This method can be implemented in transformer for protection

and avoidance of workers death in workplace. By using our project we

can able to secure them at the workplace. It is more protective and

secured method. Innovative wiremen security system will provide more

security to the linemen. And our project will reduce the electrical injury

fatal. In our technical world this kind of project will show our

improvement and also safe the life.

5.2FUTURE ENHANCEMENT

Future work is to implement this project by using finger print recognizer for more safety.

Otherwise we can implement this project using zigbee for long distance transmission.

[46]

CHAPTER-6

REFERENCES

[1]M.AminandB.F.Wollenberg,“Towardasmartgrid:Powerdeliveryfor

21stcentury,”IEEEPowerEnergyMag.,vol.3,no.5,pp.34–41,2005.

[2]R.E.Brown,“Impactofsmartgridondistributionsystemdesign,”in

Proc.IEEEPowerandEnergySoc.Gen.Meeting—Convers.Del.Elect. Energy21stCentury,2008,pp.1–4.

[3]S.D.Maqbool,M.Babar,andE.A.Al-Ammar, “Effectofdemand elasticityandpricevariationonloadprofile,”inProc.InnovationSmart GridTechnol.,IEEEPESConf.,2011,pp.1–5.

[4]J.A.Momoh,“Smartgriddesignforefficientandflexiblepowernetworks operationandcontrol,”inProc.PowerSyst.Conf.Expo.,2009,pp.1–8.

[5]A.Ipakchi,“Grid ofthefuture,”IEEEPower EnergyMag., vol.7,no.2, pp.52–62,2009.

[6]C.WangandP.Li,“Development andchallengesofdistributedgeneration,themicro-gridandsmartdistributionsystem,”Automat.Elect.Power Syst.,2010.

[7]C.W.Potter,A.Archambault,andK.Westrick,“Buildingasmartersmart gridthroughbetterrenewableenergyinformation,” inProc.PowerSyst. Conf.Expo.,2009,pp.1–5.

[8]J.W.Shim,T.Nam,J.Y.Jang,T.K. Ko,M.C.Ahn,andK.Hur,“Toward aself-healingelectricgridwithsuperconductingfaultcurrentcontrollers,” IEEETrans.Appl.Supercond.,vol.22,no.3,p.5600904,Jun.2012.

[9]M.C.AhnandT.K.Ko,“Proof-of-conceptofasmartfaultcontrollerwith asuperconductingcoilforthesmartgrid,”IEEETrans.Appl.Supercond., vol.21,no.3,pp.2201–2204,Jun.2011.

[10]R.C.Dorf,IntroductiontoElectricCircuit,7thed. Hoboken,NJ:Wiley,

2006.

[11]D.D.Roybal,“Circuitbreakerinterrupting capacityandshort-timecur- rentratings,”inConf.Rec.IEEEIASAnnu.Meeting,2004,pp.130–134.

[47]

[12]Metal Enclosed Low-Voltage AC Power Circuit Breaker SwitchgearAssemblies,ANSI/NEMAStandardC37.20.1,2002

[13]GuideforTestingMetalEnclosedSwitchgearRatedUpto38kVforInternalArcingFaults,ANSI/NEMAStandardC37.20.7,Jan.2008.

[14]Low-Voltage Switchgear and Controlgear Assemblies, IEC Standard61439-1/2,Jan.2009.

[15]StandardforMolded-Case CircuitBreakers,Molded-Case SwitchesandCircuit-BreakerEnclosures,UL489,2006.

[16]Low-VoltageSwitchgear&Controlgear,Part2CircuitBreakers,IEC60947.2(AS60947.2),2005.

[17]M.HigginsonandD.B.Durocher,“Properapplication&maintenanceof molded-casebreakerstoassuresafeandreliableoperation,”inConf.Rec. Annu.PulpPaperInd.Tech.,2009,pp.90–101.

[18]NFPA70EStandardforElectricalSafetyintheWorkplace,2009Edition.[19]NationalInstituteforOccupationalSafety&Health.[Online].Available:

http://www.cdc.gov/niosh/mining/topics/topicpage1.htm[20]ElectricalEquipmentforMines&Quarries,AS/NZS4871.1,May25,

2010.[21]IEEEGuideforPerformingArc-FlashHazardCalculations,IEEEStd

1584-2002.[22]ByproductsofSulfurHexafluoride(SF6)UseintheElectricPowerIndus-

try,U.S.Environ.ProtectionAgency,Washington,DC,Jan.2002.

[48]

APPENDIX

#include <lcd.c>

#include "keypad.h"

int1 light1on=0,light2on=0;

int8 Pass[6],Keypad_Value=0,i=0;

void Read_Keypress()

{

Keypad_Value='\0';

lcd_putc("\fEnter Password");

lcd_putc("\n");

for(i=0;i<4;i++)

{

do

{

Keypad_Value = kbd_getc();

}

while(Keypad_Value == '\0');

Pass[i]=Keypad_Value;

lcd_putc(Keypad_Value);

delay_ms(100);

}

delay_ms(100);

if(Pass[0]=='1' && Pass[1]=='2' && Pass[2]=='3' && Pass[3]=='4')

{

if(light1on==1)

[49]

{

RE0=0;

light1on=0;

lcd_putc("\fLIGHT-1 OFF");

}

else

{

RE0=1;

light1on=1;

lcd_putc("\fLIGHT-1 ON");

}

}

else if(Pass[0]=='5' && Pass[1]=='6' && Pass[2]=='7' && Pass[3]=='8')

{

if(light2on==1)

{

RE1=0;

light2on=0;

lcd_putc("\fLIGHT-2 OFF");

}

else

{

RE1=1;

light2on=1;

lcd_putc("\fLIGHT-2 ON");

}

}

[50]

else

{

lcd_putc("\fWrong Password");

}

delay_ms(1000);

}

void main()

{

TRISA=0x00;

TRISB=0xFF;

TRISC=0x00;

TRISD=0x00;

TRISE=0x00;

PORTA=0x00;

PORTB=0x00;

PORTC=0x00;

PORTD=0x00;

PORTE=0x00;

ADCON1=0x06;

ANSEL =0x00;

ANSELH=0x00;

lcd_init();

lcd_putc("\fWIREMAN SAFETY");

lcd_putc("\n SYSTEM");

RD3=1;

delay_ms(1000);

RD3=0;

[51]

delay_ms(1000);

PORTE=0x03;

light1on=1;

light2on=1;

while(true)

{

Read_Keypress();

}

}

[52]

[53]