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.

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.

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

Answer / kim leang

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

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

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)

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..

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

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

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

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;

How we can calculate what type of supply we need for an example sometimes we take 11 KV and sometime 33KV from EB ?

4 Answers  

transformers parts & function of each parts

25 Answers   Amara Raja, Bhutan Ferro Alloys Limited, Breather, Electrical, Electrical Tech, ERDA, GVK, Juniper Networks, Matrix, Mechanical, NFL, Oracle, Pyramid Plastics, RPPL, RRB, Siemens, TCS, Tulip Silk Mills,

kva/kvr

2 Answers  

WHAT ARE THE EFFECTS OF SERIES RESONANCE AND PARALLEL RESONANCE ON THE CIRCUITS PARAMETERS?

0 Answers  

Q) Write VBscript code along with QTPscript code in QTP tool for below scenario 1. Launch yahoo site(i know) 2. Do loogin(i know) 3.Click inbox link(i know) 4.Go to every page of mail box and count no.of read mails and no.of unread mails(i know) 5.Store page numbers, read mail count and unread mail count in a new excel file sheet 6.Create 10 types of graphs on that data 7.Do logout and close site(i know) 8.Save new excel files with graph

0 Answers  

how does a current carrying conductor posess a magnetic field. what is the reason for the production of electro magnetic field around the conductor

2 Answers   Vizag Steel,

How to test the Secure Elite 440 Multi function meter working condition.

0 Answers   Sadanand Constructions,

Please give me the formula stating relation between AC & Dc.

2 Answers   JP Group,

how kva rating of transformer is calculated.

6 Answers   Fluor Daniel, Siemens,

What is meant by Low Resistance Cable and High Resistance Cable.

0 Answers  

The unit of current is the:(a) Volt(b) Coulomb(c) Joule(d) Ampere

2 Answers  

WE HAVE A LOAD OF 55KW MOTOR ITS VOLTS 380 3PH AND ITS TAKING 100AMPS (ITS FULL LOAD IS 105AMPS)AND ITS CABLE IS 4CX50SQMM ,NOW ITS GETTING ABNORMAL HEATUP IN CABLE,PLZ TELL WHY ITS HEAT-UP?(CABLE LENGTH IS 15 METERS ONLY)

10 Answers