PURDUE UNIVERSITY CALUMETECE 233 MICRO COMPUTERS IN ENGINEERING

AUTOMATIC CORRECTOR OF THE POWER FACTOR

STUDENT: IVAN OCAMPODATE: MAY 8TH, 2015

After a little brain storm, the next issues had been identified in the power and energysystems field:

Power and energy losses.

Low power factor.

Inefficient systems.Keeping in mind that the energy sources are limited, and that it is necessary a better

energy use, the present project is going to be focused on the correction of the low powerfactor, because this could help us to fix the issue related to the use of energy.The next sketch shows the general image of a power system with a passive network ofcapacitors that would be connected to the main line to correct the power factor:

The capacitors bank has 4 stages:Voltage and current phase detection.Micro controller coupling.

Shift phase calculation.Capacitors bank switching.The next block diagram shows the 4 stages:

VoltageCurrent

VoltageCurrentPhaseDetection

MicroControllerPowerFactorCalculations

CapacitorsBankSwitching

The zero crossings are obtained by the voltage and current in the power line, eachin crossing detector independent zero phase shift between the zero crossings ofa signal relative to each other is determined by measuring the delay between them. Duringthis delay, n pulses are generated to the microcontroller indicating the value of degrees ofphase shift.The microcontroller, depending on the pulses detected, decide how many and whichcapacitors is connected to the line to offset the degree of phase shift causedby the inductive load, and to obtain the desired power factor. Likewise isdetermined when the power factor has been corrected.If the inductive load is lower, the micro controller proceeds to disconnectioncapacitors that are no longer needed and the discharge thereof, and keep thedesired power factor. If demand increases more capacitors will be connected to the line.For a single phase sytem, are necessary two zero crossing detectors, one for voltageand one for current, depending on the number of capacitors we will use a transistor and anopto coupler for switching them instead of SCR's.The list of I/O needed for our system is shown below:Description

Input

Voltage zero crossing detector

RA0

Current zero crossing detector

RA1

Output

Capacitor 1

RB7

Capacitor 2

RB6

Capacitor 3

RB5

Capacitor 4

RB4

LED 1

RA2

LED 2

RA3

LED 3

RA4

The circuit of our device is shown below:

The flow chart that mange our device is shown below:

Initializeregisters

Created by Trial VersionStart

Detectzero-zerolevel

N1

N

N

RA0=0

RegF,0=0?

N2

Y

Y1=RegF,0

NRegF,1=0?

N5

Read TMROReset TMROAverage

1=RA2, clrf TMRO

0=RegF,00=RegF,1

N31=RegF,3

Created by Trial VersionN4

RA1=0?

N

RegF,1=0?

N22

RegF,4=0?

YM1

Y

1=RegF,1RegF3=0?

N

M2

0=RegF,3Reg2 - 1

N

Reg2=0?

NRegF,0=0?

Cy=0?

Y

1=RA4

N

1=RA3clrf TMRO

RA2=0?

N

N6 addC

Y

YN

250=Reg2Reg3 - 11=RegF,412=Reg3250=Reg2

0=RegF,4Reg5 - Reg4

M3 reduce C

YReg3=0?

N

1 m in pass ?

Created by Trial Version

This device would help us to obtain a better use of the power in a single phase system,but it is possible to use multiple stages if we want to improve a two or three phase powersystem. The impact of the device is that will be possiible to avoid losses due to low powerfactors automatically in a fast way. The better use of energy is a contemporary issue that canbe solved if we reduce the inefficient use of energy.

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TechnicalDocuments

LM193-N, LM2903-N, LM293-N, LM393-NSNOSBJ6F OCTOBER 1999 REVISED DECEMBER 2014

LMx93-N, LM2903-N Low-Power, Low-Offset Voltage, Dual Comparators1 Features

3 Description

The LM193-N series consists of two independentprecision voltage comparators with an offset voltagespecification as low as 2.0 mV max for twocomparators which were designed specifically tooperate from a single power supply over a wide rangeof voltages. Operation from split power supplies isalso possible and the low power supply current drainis independent of the magnitude of the power supplyvoltage. These comparators also have a uniquecharacteristic in that the input common-mode voltagerange includes ground, even though operated from asingle power supply voltage.

1

Wide Supply Voltage Range: 2.0 V to 36 V Single or Dual Supplies: 1.0 V to 18 VVery Low Supply Current Drain (0.4 mA) Independent of Supply VoltageLow Input Biasing Current: 25 nALow Input Offset Current: 5 nAMaximum Offset voltage: 3 mVInput Common-Mode Voltage Range IncludesGroundDifferential Input Voltage Range Equal to thePower Supply VoltageLow Output Saturation Voltage: 250 mV at 4 mAOutput Voltage Compatible with TTL, DTL, ECL,MOS and CMOS logic systemsAvailable in the 8-Bump (12 mil) DSBGA PackageSee AN-1112 (SNVA009) for DSBGAConsiderationsAdvantages High Precision Comparators Reduced VOS Drift Over Temperature Eliminates Need for Dual Supplies Allows Sensing Near Ground Compatible with All Forms of Logic Power Drain Suitable for Battery Operation

2 Applications

Battery powered applicationsIndustrial applications

Application areas include limit comparators, simpleanalog to digital converters; pulse, squarewave andtime delay generators; wide range VCO; MOS clocktimers; multivibrators and high voltage digital logicgates. The LM193-N series was designed to directlyinterface with TTL and CMOS. When operated fromboth plus and minus power supplies, the LM19-Nseries will directly interface with MOS logic wheretheir low power drain is a distinct advantage overstandard comparators.The LM393 and LM2903 parts are available in TIsinnovative thin DSBGA package with 8 (12 mil) largebumps.Device Information(1)PART NUMBERLM193-NLM293-NLM393-NLM2903-N

PACKAGE

BODY SIZE (NOM)

TO-99 (8)

9.08 mm x 9.08 mm

SOIC (8)

4.90 mm x 3.91 mm

(1) For all available packages, see the orderable addendum atthe end of the datasheet.

4 Simplified Schematic

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,intellectual property matters and other important disclaimers. PRODUCTION DATA.

LM193-N, LM2903-N, LM293-N, LM393-NSNOSBJ6F OCTOBER 1999 REVISED DECEMBER 2014

www.ti.com

Table of Contents1234567

Features ..................................................................Applications ...........................................................Description .............................................................Simplified Schematic.............................................Revision History.....................................................Pin Configuration and Functions .........................Specifications.........................................................7.17.27.37.47.5

1111234

Absolute Maximum Ratings ..................................... 4ESD Ratings ............................................................ 4Recommended Operating Conditions....................... 4Thermal Information .................................................. 5Electrical Characteristics: LM193A V+= 5 V, TA =25C ........................................................................... 57.6 Electrical Characteristics: LM193A (V+ = 5 V) ......... 57.7 Electrical Characteristics: LMx93 and LM2903 V+= 5V, TA = 25C .............................................................. 67.8 Electrical Characteristics: LMx93 and LM2903 (V+ =5 V) (1) ......................................................................... 77.9 Typical Characteristics: LMx93 and LM193A............ 87.10 Typical Characteristics: LM2903 ............................ 9

8

Detailed Description ............................................ 108.18.28.38.4

9

Overview .................................................................Functional Block Diagram .......................................Feature Description.................................................Device Functional Modes........................................

10101010

Application and Implementation ........................ 119.1 Application Information............................................ 119.2 Typical Applications ................................................ 11

10 Power Supply Recommendations ..................... 1811 Layout................................................................... 1811.1 Layout Guidelines ................................................. 1811.2 Layout Example .................................................... 18

12 Device and Documentation Support ................. 1912.112.212.312.4

Related Links ........................................................Trademarks ...........................................................Electrostatic Discharge Caution ............................Glossary ................................................................

19191919

13 Mechanical, Packaging, and OrderableInformation ........................................................... 19

5 Revision HistoryNOTE: Page numbers for previous revisions may differ from page numbers in the current version.Changes from Revision E (March 2013) to Revision F

Page

Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device FunctionalModes, Application and Implementation section, Power Supply Recommendations section, Layout section, Deviceand Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1

Changes from Revision D (March 2013) to Revision E

2

Page

Changed layout of National Data Sheet to TI format ............................................................................................................ 1

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Copyright 19992014, Texas Instruments Incorporated

Product Folder Links: LM193-N LM2903-N LM293-N LM393-N

LM193-N, LM2903-N, LM293-N, LM393-Nwww.ti.com

SNOSBJ6F OCTOBER 1999 REVISED DECEMBER 2014

6 Pin Configuration and Functions8-Pin TO-99LMC PackageTop View

8-Pin CDIP, PDIP, SOICP and D PackageTop View

8-Pin DSBGAYZR PackageTop View

Pin FunctionsPINNO.

I/O

DESCRIPTION

NAME

PDIP/SOIC/TO-99

DSBGA

OUTA

1

A1

O

Output, Channel A

-INA

2

B1

I

Inverting Input, Channel A

+INA

3

C1

I

Noninverting Input, Channel A

GND

4

C2

P

Ground

+INB

5

C3

I

Noninverting Input, Channel B

-INB

6

B3

I

Inverting Input, Channel B

OUTB

7

A3

O

Output, Channel B

V+

8

A2

P

Positive power supply

Copyright 19992014, Texas Instruments Incorporated

Submit Documentation Feedback

Product Folder Links: LM193-N LM2903-N LM293-N LM393-N

3

LM193-N, LM2903-N, LM293-N, LM393-NSNOSBJ6F OCTOBER 1999 REVISED DECEMBER 2014

www.ti.com

7 Specifications7.1 Absolute Maximum Ratingsover operating free-air temperature range (unless otherwise noted) (1) (2) (3)MINDifferential Input Voltage

(4)

0.3

Input Voltage

(6)

UNIT

36

V

36

V

50

mA

PDIP

780

mW

TO-99

660

mW

SOIC

510

mW

DSBGA

568

mW

Input Current (VIN