09-PowerFactor

8/7/2019 09-PowerFactor

1/20

Improvement of Power Factor & EnsuringBetter Understanding

bySh.Jitendra K. Rathod,

Jalaram Consultancy & Technical Services, Raipur

[email protected]


2/20

Power Factor (PF) is the ratio between the

active power (kW) and apparent power (kVA).Trigonometrically is the Cosine of Angle

between the Reference Voltage vector and the

Current vector.

What is power factor?


3/20

VoltageVector

CurrentVector

Angle

1

Direction of Rotation


4/20

Voltage Vector

CurrentVector

Angle1

Vectors and Angle between them


5/20

Active Current

Measured Current

ReactiveCurrent

Angle 1

Current and Components


6/20

Active Power

Apparent Power

ReactivePower

Angle 1

Power Diagram


7/20

Active Energy

Apparent Energy

ReactiveEnergy

Angle 1

Energy Diagram


8/20

Glass containing Frothand Beer


9/20

Glass containing lot of Froth and

small quantity of Beer


10/20

kW

kVA1

kVAR2

Angle 1

kVA2

Angle2

kVAR1

Situation Before and Afterapplication of Capacitors


11/20

IACTIVE

IAPPARENT 1

IREACTIVE 2

Angle 1

IAPPARENT 2

Angle2

IREACTIVE 1

Current values before and afterCapacitor Application


12/20

Being a Right Angled Triangle, existing Currentcomponents shall follow Pythagoras theorem:-

IACTIVE

2 + IREACTIVE-1

2 = IAPPARENT-1

2

Being a Right Angled Triangle, the New Currentcomponents shall follow Pythagoras theorem:-

IACTIVE2 + IREACTIVE-2

2 = IAPPARENT-22

Relation between Current Values


13/20

It is considered as Lagging. Existing power factor are

taken as PF1 and improved power factor as PF2.

Old and New Power Factor


14/20

Reactive Current Switched ON = IREACTIVE-3 (IR3). We can easily measure;

this being output from the capacitors connected to the circuit.

Original Reactive component of Current = IREACTIVE-1 (IR1)

Reduced Reactive component of Current = IREACTIVE-2 (IR2)

Balance Uncompensated Reactive Current IREACTIVE-2 (IR2) = IREACTIVE-1

(IR1) - IREACTIVE-3 (IR3)

Active Current IACTIVE remains constant and hence Same Amperes.

Original Apparent Current = IAPPARENT-1 = IAPP-1= I1. We can easily measure

Reduced Apparent Current = IAPPARENT-2 = IAPP-2= I2 We can easily measure

Reduction in Apparent Current = IAPPARENT- 3 = IAPP 3 = I3. We can calculate.

Reduction in Apparent Current IAPP-3 = I3 = (I1 - I2). We can calculate.

% Reduction in Apparent Current = (I3/ I1) * 100. We can calculate.

Or, % Reduction in Apparent Current = (I1 - I2) / I1 * 100

Or, % Reduction in Apparent Current = {1 (I2/ I1)}* 100

% Reduction in Copper Loss = {1 (I2/ I1)2}* 100

Nomenclature of Current and Reduction in Load and also

reduction in Copper Losses


15/20

Existing Angle is in Degrees 1

Existing power factor in % = PF1 Cos 1

Reactive Power Switched ON kVAR3 MVAR3

New Angleis in Degrees 2

Improved power factor in % = PF2 Cos 2

New (Balance) Reactive Power kVAR2

MVAR2

New Apparent Power kVA2 MVA2

Improvement of Power Factor = PF1-PF2 Cos 1 - Cos 2

Reduction in Apparent Power kVA3 = kVA1 - kVA2

Addition of Capacitors kVAR3 = kVAR1kVAR2

Trignometrical Review


16/20

Apparent Power 325 kVA1 Existing Values Improved Values

Power Factor in % Cos 1 = 76% Cos 2 = 90%

Angle is in Degrees 1 = 40.54 2 = 25.84

Same Active Power kW = 247.000

Apparent Power kVA1 = 325.000 kVA2 = 274.444

Current at 440 Volts, in Amp. I1 = 426.452 I2 = 360.115

Reactive Power kVAR1 = 211.225 kVAR2 = 119.628

Capacitors applied kVAR3 = 211.225 kVAR1 - 119.628

kVAR2 =91.597

91.597 kVAR3/ 325 kVA1 = 0.28184

% Reduction in Apparent Power = (1 - 274.444 kVA2/

325 kVA1) =

15.56% Refer Table3

E.C. i.e. % Reduction in Copper Losses = 1 - (360.115 I2/

426.452 I1)2 =

28.69% Refer Table4

Numerical Values Before and After Capacitor

Application


17/20

kW

kVA1

kVAR2

Angle 1

kVA2

Angle2

kVAR1

Reduction of Current


18/20

RESULT

Reduction in Apparent Power i.e. kVA3 = kVA1 - kVA2

Addition of Reactive Power i.e. kVAR3 = kVAR1 - kVAR2

Being a Right Angled Triangle, existing power shallfollow Pythagoras theorem:-

kW2 + kVAR12 = kVA1

2

Being a Right Angled Triangle, the New Power triangle

shall also follow Pythagoras theorem:-kW2 + kVAR2

2 = kVA22

Components of Power & Inter-

relationship


19/20

S. No. Rating of individual Induction motor in . KVAR rating of LT capacitors

1 3 and above up to 5 1 KVAR

2 Above 5 to 7.5 2 KVAR

3 Above 7.5 to 10 3 KVAR

4 Above 10 to 15 4 KVAR






CSEB suggested values


20/20

09-PowerFactor

Documents

Transcript of 09-PowerFactor