1. POWER FACTOR CORRECTION
WISEMAN NENE
EIT – ELECTRICAL
ESTON SUGAR MILL

2. POWER FACTOR CORRECTION
AS A MEANS OF COST SAVINGS

3. CONTENT INTRODUCTION OBJECTIVES NATURE OF ELECTRICAL POWER/LOAD
POWER FACTOR THEORY

4. ADVANTAGES OF IMPROVED POWER FACTOR
DISADVANTAGES OF LOW POWER FACTOR
METHODS OF IMPROVING POWER FACTOR
OVERVIEW OF THE SYSTEM
SYSTEM BREAKDOWN

5. POWER AND COSTS SAVINGS
PROJECT COSTS
COSTS RECOVERY PERIOD
SAFETY AND MAINTENANCE OF THE SYSTEM
CONCLUSION

6. INTRODUCTION
COSTS SAVINGS IS ONE OF THE MEASURE DRIVERS IN INDUSTRY FOR BUSINESS SUSTAINABILITY
POWER FACTOR CORRECTION IS ONE OF THE MEANS THAT CAN BE USED TO REDUCE COSTS

7. NATURE OF ELECTRICAL LOAD
Resistive - I and V peaks are simultaneous
The angle between the two is zero
Inductive - I lags V
The angle between the two is negative
Capacitive – I leads V
The angle between the two is positive

8. OBJECTIVES
TO INVESTIGATE MEANS OF COST REDUCTION FROM THE ELECTRICAL PERSPECTIVE – (POWER FACTOR CORRECTION)

9. POWER FACTOR THEORY PF = ACTIVE POWER / APPARENT POWER = P / S
= kW / kVA
ACTIVE POWER (P) = kW
APPARENT POWER (S) = kVA

10. POWER TRIANGLE

11. SYSTEM BEFORE PFC
PF = 0.68 Lagging

12. DESIRED MINIMUM SYSTEM TRIANGLE
PF = 0.8 Lagging

13. NEW SYSTEM POWER TRIANGLE
PF = 0.92 Lagging

14. ADVANTAGES OF IMPROVED PF
REDUCED APPARENT POWER PRODUCED
IMPROVED PLANT EFFICIENCY
ADDITIONAL LOADS CAN BE ADDED TO THE SYSTEM
REDUCED OVERLOADING OF CABLES, TRANSFORMERS, SWITCHGEAR, ETC.
IMPROVED NETWORK VOLTAGE
IMPROVED STARTING TORQUE OF MOTORS

15. DISADVANTAGES OF LOW PF
INCREASES ELECTRICITY COSTS
CAUSES OVERLOADING OF GENERATORS, TRANSFORMERS AND DISTRIBUTION SYSTEM
GREATER VOLTAGE DROPS AND POWER LOSSES
LOW EFFICIENCY AND UNNECESSARY WEAR AND TEAR TO INDUSTRIAL ELECTRICAL EQUIPMENT
REDUCES LOAD HANDLING OF THE PLANTS’ ELECTRICAL SYSTEM

16. METHODS OF IMPROVING POWER FACTOR
SYNCHRONOUS MOTORS
STATIC VAR COMPENSATORS
STATIC CAPACITORS

17. METHODS OF IMPROVING POWER FACTOR
SYNCHRONOUS MOTORS
Has long service life
Can withstand higher short circuit currents
High maintenance and installation costs
STATIC VAR COMPENSATORS
Fast response system
System is very expensive

18. STATIC CAPACITORS
Simple and easy to install
Cannot be repaired

19. CONNECTION TO THE NETWORK
Basic connection diagram for static capacitors

20. SYSTEM CONFIGURATION 4 x 48kVAr + 3 x 50 kVAr = 342 kVAr
FRONT – END SECTION
4 x 48kVAr + 3 x 50 kVAr
= 342 kVAr
BACK – END SECTION
= 6 x 62.5 kVAr
= 375 kVAr

21. SYSTEM OPERATION Manual Mode
Uses a selector switch to select a stage
Automatic – using Epcos BR6000 PFC Controller
Uses a selector switch to automatically select a stage

22. POWER AND COSTS SAVINGS
Electrical saving in terms of the power consumed
P = kW
P = kW
@ 0.68 PF , S = 631 kVA
And at:
@ 0.92 PF, S = kVA
STOTAL = SOLD – SNEW
= kVA
I = S/√3 x 525
= A
P = √3 V I Cos θ
= kW

23. RAND VALUE SAVING (ACTUAL)
Assuming 24 hours/day for /kWh and saving kWh, National grid Power
Energy Charge Saving = x 24 x 30 x
= R 43,821.89/month

24. POWER SAVINGS (BACK-END)
P = kW
@ 0.61 PF, SOLD = 1.48 MVA
@ 0.8 PF, SNEW = 1.13 MVA
STOTAL= SOLD – SNEW = 350 kVA
I = S/√3 x 525
= A
P = √3 V I Cos θ
= 280 kW

25. SAVINGS ( RAND-VALUE, BACK-END)
Assuming 24 hours/day for /kWh and saving 280 kW hourly:
Energy Charge Saving = 280 x 24 x 30 x
= R 81,023.04/month

26. OVERALL POWER / COST SAVINGS
For 2010 season
Eskom used during crushing=331.3 hrs, [ to ]
Electrical Power saved;
P FRONT-END = kW
P BACK-END = 280 kW
Total Power Saved (2010 season)
= kW kW
= kW
= kW x 331.3hrs
= MWh
= kWh x R /kWh = R 57,446.00

27. BUDGET & COSTS RECOVERY PERIOD
Approximately R
Source: Electrical Department Budget
Recoverable: Within 1 Month on National Grid

28. FINAL SYSTEM PICTURES
The following pictures shows the installation locations and the results obtained from the front-end section

29. CONTROLLER
Controller - Epcos BR6000

30. CONTROL
Auto and Manual Control

31. CAPACITOR BANKS

32. CONTROL PANELS

33. MAIN PANELS

34. DISPLAYS
With all banks OFF

35. WITH 6 BANKS ON .

36. PF ALL BANKS ON
PF = 0.92 Lagging

37. BACK-END SECTION

38. SAFETY No unauthorized person should switch the system ON/OFF.
Before opening the capacitor banks panels, make sure the main isolator is off and wait for at least 5minutes for the capacitors to discharge

39. CONCLUSION
As seen on the pictures in the previous slides, the new system was successful.
The power factor was corrected from 0.68 lagging to 0.92 lagging in the front-end and from 0.61 to 0.8 lagging in the back-end section

40. CONCLUSION cont.
The costs and power savings were significant at MWh during the 4 months period recorded during the 2010 season

41. ACKNOWLEDGEMENTS
ESTON ENGINEERING TEAM

42. THANK YOU!!!
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