what is pf. how to calculate capacitor bank value to
maintain unity pf.




Answers were Sorted based on User's Feedback



what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / nilesh kumar singh

Power Factor is defined as the ratio of Real power and
Apparent power.

for calculating Capacitor bank value the formula is :

kVAr = KW {tan(cos^-1 Phi e) - tan(Cos^-1 Phi d)}

Where - Phi e = existing Power Factor.
Phi d = Desired Power Factor.

Is This Answer Correct ?    99 Yes 8 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / rajendra singh

for calculating Capacitor bank value the formula is :

kVAr = KW {tan(cos^-1 Phi e) - tan(Cos^-1 Phi d)}

Where - Phi e = existing Power Factor.
Phi d = Desired Power Factor.

Is This Answer Correct ?    42 Yes 8 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / shivappa

to calculate desired capacitor value, the formula is

KVAR= KW(TAN PHI 1 - TAN PHI 2 )

WHERE PHI 1 = EXISTING POWER FACTOR
PHI 2 = REQUIRED POWER FACTOR

Is This Answer Correct ?    23 Yes 14 No




what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / kim leang

KVAR= KW(TAN PHI 1 - TAN PHI 2 )

WHERE PHI 1 = EXISTING POWER FACTOR
PHI 2 = REQUIRED POWER FACTOR

Is This Answer Correct ?    14 Yes 9 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / midhun

Calculation and selection of required capacitor rating
Qc = P * {tan [acos (pf1)] - tan [ acos (pf2)]}
Qc = required capacitor output (kVAr)
pf1 = actual power factor
pf2 = target power factor
P = real power (kW)

Is This Answer Correct ?    6 Yes 1 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / fancy102

hi..i also interested in it..i am carrying out pf
measurement system and i am headache in how to maintain the
unity pf too..

Is This Answer Correct ?    40 Yes 36 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / ezzuddin

The correct answer and below is the proof of the formula:

KVAR= KW X [√(1–(COSФ)^2)]/COSФ

The proof:
Pythagoras Theorem states that in a right-angled triangle
the square of the hypotenuse is equal to the sum of the
squares of the other two sides.
so that:
Q is the hypotenuse.
S is the opposite.
P is the adjacent.
TanФ= opposite/adjacent = S/P -----> S=P x(TanФ)
Pf=COSФ= adjacent/hypotenuse = P/Q ---->Q=P/COSФ
Pythagoras said that:
Q^2= P^2 + S^2
P^2/(COSФ)^2= P^2 + (P^2 x (TanФ)^2)
by divide P^2:
1/(COSФ)^2 = 1 + (TanФ)^2
by changing the both sides:
(TanФ)^2 = (1/(COSФ)^2) - 1
(TanФ)^2 = (1/(COSФ)^2) - ((COSФ)^2/(COSФ)^2)
by Taking the (1/(COSФ)^2) Common factor:
(TanФ)^2 = {1/(COSФ)^2)} x ( 1 - (COSФ)^2)
by taking the square root:

TanФ = [√(1–(COSФ)^2)]/COSФ

so that:
KVAR = KW x [√(1–(COSФ)^2)]/COSФ

Is This Answer Correct ?    5 Yes 1 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / santosh

react power kvar=v i sin phi, we know p.f=1,i.e cos phi
calculate sin phi,v i values from total load

Is This Answer Correct ?    14 Yes 11 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / vekuva

KVAR= KW(TAN PHI 1 - TAN PHI 2 )

WHERE PHI 1 = EXISTING POWER FACTOR ANGLE i.e., COS^¯1(p.f1)
PHI 2 = REQUIRED POWER FACTOR ANGLE i.e., COS^¯1(p.f2)
p.f 1 = EXISTING POWER FACTOR
p.f 2 = REQUIRED POWER FACTOR

Is This Answer Correct ?    5 Yes 2 No

what is pf. how to calculate capacitor bank value to maintain unity pf...

Answer / ezzuddin

The correct answer and below is the proof of the formula:

KVAR= KW X [Sqrt(1–(CosQ)^2)]/CosQ;

The proof:
Pythagoras Theorem states that in a right-angled triangle
the square of the hypotenuse is equal to the sum of the
squares of the other two sides.
so that:
C is the hypotenuse.
S is the opposite.
P is the adjacent.
TanQ= opposite/adjacent = S/P -----> S=P x(TanQ;)
Pf=CosQ;= adjacent/hypotenuse = P/C ---->C=P/CosQ;
Pythagoras said that:
C^2= P^2 + S^2
P^2/(CosQ)^2= P^2 + (P^2 x (TanQ)^2)
by divide P^2:
1/(CosQ)^2 = 1 + (TanQ)^2
by changing the both sides:
(TanQ)^2 = (1/(CosQ)^2) - 1
(TanQ)^2 = (1/(CosQ)^2) - ((CosQ)^2/(CosQ)^2)
by Taking the (1/(COSQ)^2) Common factor:
(TanQ)^2 = {1/(CosQ)^2)} x ( 1 - (CosQ)^2)
by taking the square root:

TanQ; = [Sqrt(1–(CosQ)^2)]/CosQ;

so that:
KVAR = KW x [Sqrt(1–(CosQ)^2)]/CosQ;

Is This Answer Correct ?    4 Yes 1 No

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