Automatic Power Factor Controller using PICTURE Microcontroller Composition


Automatic Power Factor Controller using PIC Microcontroller



Automatic Power Factor Controller using Microcontroller M Y � DI Versus Y A � S Y A MA L A � (HTTP S i9000: / as well as E L E CTRO S Um ME. COMPANY M/ A UTHO R/ S DV 1 1 6 / )� as well as � 1 3 several � COMPANY MME NTS (HTTP H: / as well as E D E CTRO S Um ME. COMPANY M/ A UTO MUM TI C­P O ALL OF US R­FA CTO R­CO NTRO L L E R­US I NG ­ MI CRO COMPANY NTRO T L Elizabeth R/ # CO MME NTS )

Sensor Breakout Boards

electronic engineering projects ask for your needed sensor board The� thirst� for� new� sources� of� energy� is� unquenchable, � but� we� seldom� realize� that� we� are wasting� a� part� of� the� electrical� energy� every� day� due� to� the� lagging� power� factor� in� the inductive loads we use.  Hence there is an urgent need to avoid this wastage of energy. Before getting into the details of Power factor correction,  lets just brush our knowledge about the� term� " power� factor”. � In� simple� words� power� factor� basically� states� how� far� the� energy provided has been utilized.  The maximum value of power factor is unity.  So closer the value of P. F to unity,  better is the utility of energy or lesser is the wastage.  In electrical terms Power factor is basically defined as the ratio of the active power to reactive power or it is the phase difference� between� voltage� and� current. � Active� power� performs� useful� work� while� Reactive power� does� no� useful� work� but� is� used� for� developing� the� magnetic� field� required� by� the unit.

Most of the devices we use have power factor less than unity.  Hence there is a requirement to� bring� this� power� factor� close� to� oneness. � Here� we� are� presenting� a� prototype� for� automatic power factor correction using PIC Microcontroller.

Circuit Diagram­power­factor­controller­using­microcontroller/



Automatic Power Factor Controller using PIC Microcontroller

(­content/uploads/2013/05/Automatic­Power­Factor­Controller­ using­PIC­Microcontroller­Circuit­Diagram. jpg)

Automatic Power Factor Controller using PIC Microcontroller Circuit Diagram


Comparator Section

The 230 V,  50 Hz is step downed using voltage transformer and current transformer is used to extract the waveforms of current.  The output of the voltage transformer is proportional to the� voltage� across� the� load� and� output� of� current� transformer� is� proportional� to� the current� through� the� load. � These� waveforms� are� fed� to� Voltage� Comparators constructed� using� LM358� op­amp. � Since� it� is� a� zero� crossing� detector, � its output� changes� during� zero� crossing� of� the� current� and� voltage� waveforms. � These� outputs are fed to the PIC which does the further power factor calculations.­power­factor­controller­using­microcontroller/



Automatic Power Factor Controller using PIC Microcontroller

Microcontroller Section

PIC 16F877A microcontroller is the heart of this Automatic Power Factor Controller,  it find, displays and controls the Power Factor..  To correct power factor,  first we need to find the current power factor.  It can be find by taking tangent of ratio of time between zero crossing of current and voltage waveforms and two successive zero crossing of voltage waveform.  Then it displays the calculated power factor in the 16×2 LCD Display and switches ON the capacitors if required.

Correction Section

When load is connected the power factor is calculated by the PIC microcontroller.  If the calculated power factor is less than 0. 9 then the relay switches on the capacitor.  The relays are switched using ULN2003 (­high­voltage­current­driver/) which is basically a driver IC.  ULN2003 consists of seven DARLINGTON PAIRS. The current lead in capacitor compensates the corresponding current lag which is usually...

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