The document describes a project that uses a microcontroller to automatically engage the appropriate number of shunt capacitors for an inductive load to improve the power factor to 0.95 or greater. The microcontroller measures the time lag between the voltage and current pulses using operational amplifiers, then uses this information to actuate relays that connect shunt capacitors to the load circuit as needed. Key hardware components include the microcontroller, relays, relay drivers, current transformers, and shunt capacitors.

1. POWER FACTOR IMPROVEMENT BY
AUTOMATICALLY ENGAGING APPROPRIATE
NUMBER OF SHUNT CAPACITOR FOR
INDUCTIVE LOADS
Under the Guidance of
Submitted by
Project Title

2. Power factor is defined as the ratio of real power to apparent power.
 Where real power is the time integral of the instantaneous power
measured over a full period and the apparent power is simply the product
of the RMS voltage and RMS current measured over the entire period.
The time lag between the zero voltage pulse and zero current pulse duly
generated by suitable operational amplifier circuits are fed to two
interrupt pins of the microcontroller where the program takes over to
actuate appropriate number of relays at its output for bringing shunt
capacitors into the load circuit to get the power factor till it reaches 0.95.
ABSTARCT

3. PROJECT BLOCK DIAGRAM

4. MICROCONTROLLER (AT89S52/AT89C51)
RELAY
RELAY DRIVER
LCD
CURRENT TRANSFORMER
INDUCTIVE LOAD
SHUNT CAPACITOR
PUSH BUTTONS
LED
1N4007 / 1N4148
RESISTOR
CAPACITOR
HARDWARE COMPONENTS

5. POWER SUPPLY
230 V AC
50 Hz
5V
DC
12V step down
transformer
Filter(470µf)
5v RegulatorBridge rectifier

6. MICROCONTROLLER
• It is a smaller computer
• Has on-chip RAM, ROM, I/O ports...
RAM ROM
I/O
Port
Timer
Serial
COM
Port
Microcontroller
CPU
A single chip

7. INTERNAL STRUCTURE OF A MICRO CONTROLLER-
AT89S52/51
CPU
On-chip
RAM
On-chip
ROM for
program
code
4 I/O Ports
Timer 0
Serial
Port
OSC
Interrup
t
Control
External interrupts
Timer 1
Timer/Counter
Bus
Control
TxD RxDP0 P1 P2 P3
Address/Data
Counter
Inputs

8. Features of AT89S51/52
 Compatible with MCS®-51 Products
 8K Bytes of In-System Programmable (ISP) Flash Memory
 Endurance: 10,000 Write/Erase Cycles
 4.0V to 5.5V Operating Range
 Fully Static Operation: 0 Hz to 33 MHz
 256 x 8-bit Internal RAM
 32 Programmable I/O Lines
 Three 16-bit Timer/Counters
 Eight Interrupt Sources
 Full Duplex UART Serial Channel
 Interrupt Recovery from Power-down Mode
 Watchdog Timer
 Dual Data Pointer

9. Pin Description

10. RELAY
IT IS A ELECTRO MAGNETIC SWITCH
USED TO CONTROL THE ELECTRICAL DEVICES
COPPER CORE MAGNETIC FLUX PLAYS MAIN ROLE HERE

11. The relay's switch connections are usually labeled COM, NC and
NO:
COM = Common, always connect to this; it is the moving part of
the itch.
NC = Normally Closed, COM is connected to this when the relay
coil is off.
NO = Normally Open, COM is connected to this when the relay
coil is on

12. RELAY DRIVER (ULN 2003)
ULN2003 is a high voltage and high current Darlington
transistor array
It consists of seven NPN Darlington pairs that feature high-
voltage outputs with common-cathode Clamp diode for
switching inductive loads.
The ULN2003 has a 2.7kW series base resistor for each
Darlington pair for operation directly with TTL or 5V
CMOS devices.
Current, Output Max:500mA
Voltage, Input Max:5V
Voltage, Output Max:50V

13. Fig: ULN 2003

14. QUAD VOLTAGE COMPARATOR LM339
FEATURES
● Wide single supply voltage range 2.0VDC TO 36VDC or dual supplies
±1.0VDC to ±18VDC
● Very low supply current drain (0.8 ㎃ ) independent
of supply voltage (1.0 ㎽ /comparator at 5.0VDC)
● Low input biasing current 25 ㎁
● Low input offset current ±5 ㎁ and offset voltage
● Input common-mode voltage range includes ground
● Differential input voltage range equal to the power
supply voltage
● Low output 250 ㎷ at 4 ㎃ saturation voltage
● Output voltage compatible with TTL, DTL, ECL, MOS
and CMOS logic system
● Moisture Sensitivity Level 3

15. LIQUID CRYSTAL DISPLAY (LCD)
Most common LCDs connected to the microcontrollers are
16x2 and 20x2 displays.
This means 16 characters per line by 2 lines and 20
characters per line by 2 lines, respectively.
The standard is referred to as HD44780U, which refers to
the controller chip which receives data from an external
source (and communicates directly with the LCD.

16. LCD BACKGROUND
If an 8-bit data bus is used the LCD will require 11 data lines
(3 control lines plus the 8 lines for the data bus)
The three control lines are referred to as EN, RS, and RW
EN=Enable (used to tell the LCD that you are sending it data)
RS=Register Select (When RS is low (0), data is treated as a command)
(When RS is High(1), data being sent is text data )
R/W=Read/Write (When RW is low (0), the data written to the LCD)
(When RW is low (0), the data reading to the LCD)

17. Soft ware Requirements
• Keil an ARM Company makes C compilers, macro assemblers, real-
time kernels, debuggers, simulators, integrated environments,
evaluation boards, and emulators for ARM7/ARM9/Cortex-M3,
XC16x/C16x/ST10, 251, and 8051 MCU families.
• Compilers are programs used to convert a High Level Language to
object code. Desktop compilers produce an output object code for the
underlying microprocessor, but not for other microprocessors.

18. • i.e the programs written in one of the HLL like ‘C’ will compile the
code to run on the system for a particular processor like x86
(underlying microprocessor in the computer).
• For example compilers for Dos platform is different from the
Compilers for Unix platform So if one wants to define a compiler
then compiler is a program that translates source code into object
code.

19. THANKYOU