Vardhman Fabrics , Budhni MP - Knowledge Platform · Low Power factor at Primary & Secondary Distribution System In Industry most LT distribution circuits normally the Power Factor

Vardhman Fabrics , Budhni (M.P)

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Contentsv System Loss

vCable Loss

vPower factor

vHarmonics

vTransformer Selection

vInduction Motor

vLighting

v Pumps



Power Transmission & Distribution ......Loss



Power Transmission & Distribution



System Losses

Low Power factor

Switching Off Transformr

Transformer Sizing

& Selection

Feeder Phase Current & Load

Balancing

Location of Transformer

Inadequte Size of

Conductor

LengthyDistribution Line

System Loss



Lengthy Distribution Line

In practically 11 KV and 415 volts lines, in Comapny areas are extended over long distances to feed loads scattered over large areas.

This results in high line resistance and therefore high I2R losses in the line.

I2R Loss Depends on

ØLoading % of Cable

ØResistance / KM of Cable

vHence Increased in Length of Cable results in more losses in cable



Sr.No. Cable Description

No. of cable Run

Length of cable

Loading %

Total Loss KW /Hr

1

3.5 Core Al. XLPE Insulated Armoured LT Cable 3.5 x 300

3 310 Meter 60% 13.4958

KW/Hr

If the Length of cable Increased from 310 Meter to 390 Meter than Total Power Loss Will be Increased

Sr.No. Cable Description

No. of cable Run

Length of cable

Loading %

Total Loss /Hr

1

3.5 Core Al. XLPE Insulated Armoured LT Cable 3.5 x 300

3 390 Meter 60%

16.8696KW/Hr

Power Loss Increased

by =3.37KW/Hr.

Sample Analysis - Power Loss KW / Hr

Analysis Study



Cable Selection Criteria

During Selection of cable following Criteria Should be taken into accounts.

ØType Of Insulation

ØType of Conductor

ØType of Cable

ØCurrent Rating

ØVoltage Rating

ØPermissible Voltage Drop

ØOverload & Short Circuit Withstand Capacity

ØBending Radius Cable Sizing



Installation of Distribution Transformer away from Load Centre

¢ In Industry Distribution Transformers are not located centrally with respect to Load Feeder . Consequently, the farthest Load Feeder obtain an extremity low voltage even though a good voltage levels maintained at the transformers secondary.

¢ This again leads to higher line losses , as a results of Decreased Voltage at farthest Load feeder.

T/F Location

Description HT LT Length @ LoadEnd

1200 Meter Actual Length

Length @ Load End

1000 Meter Actual Length + Difference Length

Total Saving (INR) / Transformer Load End --------Rs. 14.07 / Transformer



Low Power factor at Primary & Secondary Distribution System

In Industry most LT distribution circuits normally the Power Factor ranges from 0.80 to 0.85.

A low Power Factor contributes towards high distribution losses.

For a given load, if the Power Factor is low, the current drawn in high And the losses proportional to square of the current will be more.

Thus, line losses owing to the poor PF can be reduced by improving the Power Factor.



0

10

20

30

40

50

60

70

80

0.5 0.6 0.7 0.8 0.9 1

Saving in Cable Losses

P.F.1.0

0.950.90.85

0.8

Initial P.F.

%

Saving



0102030405060708090

100

1 0.9 0.8 0.7 0.6 0.5

% Rise in Current w.r.t. decrease in Power Factor

% Rise in I n

P.F.

Relation between Current & Power factor



Saving in losses = Wr x K1

Wr = Full load copper loss of the transformer

connected load in Kwk1

KVA rating of the transformer

1Cos Ø1

1Cos Ø2

-

Reduction in Transformer Losses by Improving P.F



Case Study - Reduction in Transformer Losses by Improving P.F

Copper Loss = 20000 WattsConnected Load = 1800 KWRunning Power Factor = 0.7Improved Power factor =0.9Transformer Rating = 2500KVA

Saving in Losses = 20000 x 1800 / 2500 x ( 1/0.7 - 1/0.9)

= 4464 Watts / Hr.

Annual Saving = ( 4464/1000) x 24 x 363= 38890 KWH / Annum

Annual Saving ( INR) = Rs. 1.95 Lacs / Annum.

(Considering Rs. 5 / Unit)



Facts about Harmonics

Harmonics :- Additional Variable Voltage & Current Waveform Created by Non - Linear Load which causes distortion of Orignal Sinusoidal Waveform is Called as " Harmonics"

How to Identify Harmonics in System

If Peak Factor is showing less than 1.41 in RMS Meter installed in feeder than it is indication of Presence of harmonics in System

By Measuring the Phase & Neutral Current of balance System

By Proper Inspection of Connection

By Comparing Transformer Temperature Condition



Active Filters

Hybrid Filters

Tuned Filters

14% Detuned Filters

7% Detuning Filters

Cost Technology

Harmonic Mitigating Solutions

How to Eliminate Harmonics in System



Increase Efficiency, Profitability Reliability

Harmonics

Harmonics are distorted electrical waveforms that introduce inefficiencies into your electrical system. They produce wasteful heat and can cause plant issues and fees from your local power company.

Harmonics flow into the electrical system as a result of nonlinear electronic switching devices, such as adjustable frequency drives (AFDs), computer power supplies and energy-efficient lighting.

Similarly, companies with heavy motor, AFD and lighting loads need to be aware of the problems that harmonics can cause. These problems include:

§ Increased electrical usage§ Increased wear and tear on motors/equipment§ Higher maintenance costs§ Power quality problems upstream and downstream§ Utility penalties for introducing problems to the power grid

The charts shown below illustrate motor and transformer efficiency decreases due to system harmonics.









Effect of Voltage Unbalance

v Transformer failure :- Three phase voltage with high Voltage Unbalance ratio may cause the flux inside the transformer core to be asymmetrical. This asymmetrical flux will cause extra core loss, raise the winding temperature and may even cause transformer failure in a severe case.

v Extra Power Loss

v Motor Failure



Transformer Sizing & Selection

Distribution Transformer use Copper Conductor Winding to indude magnetic field into grain-oriented silicon steel core .

Therefore transformer have both Load Losses & no Load Core losses.

Load losses are varies with Load while the no Load losses are constant as it depends on Volatge.

Total Losses = No. Load Loss + Load Loss ( I^2R Loss)



Application of Flux Density & Current Density in Transformer Selection

Flux Density & Current density plays very important role in reducing the Losses of Transformer ,it is also Proposed to reduce the Size & Weight of Transformer i.e Core Size & Copper Volume by marginally increasing the Flux density & Current density.

It is also important to take Care of Efficiency & Temperature rise of Transformer during marginally increasing the flux density & Current density.



Sr.No. Advantages Disadvantages

1 Area of Cross - Section of Core is Reduced

Iron Loss ( Eddy Current & Hystresis Loss Increased)

2 Iron Weight & Transformer Weight is reduced Efficiency is Marginally Reduced

3Mean Turn Length of High

Voltage & Low Voltage Winding is reduced

Temperature rise is Increased Slightly

4 Copper Weight & Copper Loss is Reduced

Saturation Occured so Magnetising Current increased

Slightly with result Power factor become Slightly Poor

Effect of Flux Density in Transformer



Sr.No. Advantages Disadvantages

1

Winding Cross- Sectional Area is Reduced due to this Volume & Copper

Weight is Reduced

Efficiency of Transformer is reduced slightly

2 Copper Loss & Temperature Rise Increased Slightly

3

Load is not Constant & Vary from no Load to full Load in

Distribution Transformer & accordingly Copper Loss

Increased Slightly.

Effect of Current Density in Transformer



AS PER CBIP TRANSFORMER



Induction Motor



Siemens Payback Caluculation Sheet

If we reduced the Motor Capacity from 30KW to 22 KW & Increased the Efficiency from IE2 to IE3 , than Payback Period Investment comes in 6 .6 Year.



Siemens Payback Caluculation Sheet

If we Increased Only Efficiency of Motor on Same Motor Capacity than Pay back Investment comes in 38.9 Years.



Motor system efficiency

Cumulative efficiency of the system is the product of all intermittent efficiencies

Cumulative System efficiency

=0.92*0.99*0.998*0.62=56.4%











Lighting Energy Saver Selection

Lamp Characteristics :- Lamp specially modern Fluorescnt lamps are basically low impendace

These Fluorescent lamps do not have a linear Lumens-watts curve .It means an increase in power supplied will not give you proportional increase in light output . Hence Slightly reducing the power supplied does not reduce the light output proportionally.

Now adays the said technology of reducing the power is achieved through Lighting energy saver Coolite ( Make -: Schiender).



Differences between Voltage Stablizer & Coolite



Benefits of Coolite - Lighting Energy Saver

¢ Saves energy, Improves Efficiency

¢ Improves PF

¢ Prolongs the life of Lamps

¢ Reduces Harmonics

¢ Compact & Rugged

¢ Quick Payback Period



¢ The Lumen curve saturates¢ 15% Power Reduction gives only 5% Lumen reduction for Discharge Lamps

� Eye cannot perceive < 50 Lux change in 250 Lux� Improved Lumens / Watt

Coolite Principle

0

20

40

60

80

100

0 10 20 30 40 50 60 70 80 90 100 110 120 130

Mea

sure

d Li

ght (

%)

Power (W)

100%

85%80%

100%

85%80%

Perc

eive

d Li

ght (

%)

For 40W Tube 15% less power = 34W

Gas-discharge LampFluorescent, CFL Incandescent Lamp

Perc

eive

d Li

ght (

%)



PUMP AUDIT RESULT



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Vardhman Fabrics , Budhni MP - Knowledge Platform · Low Power factor at Primary & Secondary Distribution System In Industry most LT distribution circuits normally the Power Factor

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