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Explaining Power Factor Correction Capacitor

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#1 samboo


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Posted 14 April 2015 - 10:42 AM

1-once voltage is impressed on both inductor and capacitor at t=0+,capacitor branch sends current to one end of the inductor while another current is send down the other end of the inductor,therefore the 2 cancels out(same in magnitude opposite in direction)?? am i right or wrong??


2-if i am nearly right with the above and that both current cancels out then their associated magnetic field would also cancels out ?? right or wrong?? and if so where from do we get the magnetizing current necessary to work the motor???


3-i red on your notes"the capacitor provide current that leads the voltage.this combines with the current associated with the magnetic fields that lags the voltage and cancels it out, if sized correctly"  

my question no 2 is only to fully understand your above statement .


please attend to my specific questions without much math and  i really thanks you in advance for doing the effort for me .

#2 marke


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Posted 14 April 2015 - 11:29 PM

Applying power factor correction does not alter the current flowing into the motor.

If you measure the current that flows into the motor with and without a capacitor, there is no difference, however, the magnetising current flowing into the motor has a phase angle that is 90 degrees behind the voltage and the current flowing into the capacitor is 90 degrees ahead of the applied voltage.


If we measure the current flowing to the motor and to the capacitor, then the capacitive current is 180 degrees out of phase with the inductive current and so it cancels out of the total current, but not the current flowing into the motor.


Your description in 1 is confused and not correct.

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