The document discusses power factor correction, highlighting its definition, causes of low power factor, and various correction methods including fixed capacitors, synchronous condensers, and static compensators. Additionally, it covers the advantages and disadvantages of each method, along with economic considerations for improving power factor. The conclusion emphasizes the need to select electrical equipment based on load requirements to optimize costs.

1. Niraj Kachariya (151020011011)
Soham Patel (151020011023)
POWER FACTOR CORRECTION

2. What is Power Factor ? ?
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3.  If power supply P=V*I*cosΔ ; cosΔ is called Power Factor.
 Power factor = Real power / Apparent power .
 Power factor in Inductive, Capacitive & Resistive load .
 Power factor is a measure of an electrical system efficiency.
 Power factor is represented as % or a decimal.
 Range is between 0 to 1 in decimal .
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4. Causes Of Low Power Factor
Main cause is Inductive load
Varying load on power system
Harmonic Current
Other Cases … 4

5. Drawback Of Low Power Factor
 Low Efficiency
 Penalty from Electric Power Supply Company for low power factor
 Poor voltage regulation and large voltage drop
 Large KVA rating and size of electrical equipment
 Large line losses (Copper losses)
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6. How to improve ??
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7. Power Factor Correction Methods
• Fixed Capcitors
• Synchronous Condensors
• Phase Advancers
• Switch Capacitors
• Static Var Compensator(SVC)
• Static SynchronousCompensator(STATCOM)
• Modulated power filter capacitor compensator
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8. Fixed Capcitors
• The power factor can be improved by connecting capacitors in
parallel with the equipment operating at lagging power factor.
• The capacitor draws a leading current and partly or completely
neutralizes the lagging reactive component of load current.
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9. Fixed Capcitors
Advantages
(i)They have low losses.
(ii)They require little maintenance as there are no rotating
parts.
(iii)They can be easily installed as they are light and require no
foundation.
(iv)They can work under ordinary atmospheric conditions.
Disadvantages
(i)They have short service life ranging from 8 to 10 years.
(ii)They are easily damaged if the voltage exceeds the rated
value.
(iii)Once the capacitors are damaged, their repair is
uneconomical.
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10. Location of capacitor on motor circuit
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11. Synchronous Condensors
• A synchronous motor takes a leading current when over-excited and,
therefore, behaves as a capacitor.
• An over-excited synchronous motor running on no load is known as
synchronous condenser.
• When such a machine is connected in parallel with the supply, it takes a
leading current which partly neutralises the lagging reactive component of
the load.
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12. Synchronous Condenser
Advantages
(i) By varying the field excitation, the magnitude of current drawn by the
motor can be changed by any amount. This helps in achieving stepless
control of power factor.
(ii) The motor windings have high thermal stability to short circuit currents.
(iii) The faults can be removed easily.
Disadvantages
(i) There are considerable losses in the motor.
(ii) The maintenance cost is high.
(iii) It produces noise.
(iv) Except in sizes above 500 kVA, the cost is greater than that of static
capacitors of the same rating.
(v) As a synchronous motor has no self-starting torque, therefore, an
auxiliary equipment has to be provided for this purpose. 12

13. Synchronous Condensers 13

14. Phase Advancers
 If the exciting ampere turns can be provided from some other a.c.
source, then the stator winding will be relieved of exciting current and
the power factor of the motor can be improved
 phase advancer which is simply an a.c. exciter.
 It provides exciting ampere turns to the rotor circuit at slip
frequency.
Advantage
i. lagging kVAR drawn by the motor are considerably reduced.
ii. It can be used instead of synchronous motors.
Disadvantage
i. they are not economical for motors below 200 H.P.
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15. Phase Advancer
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16. PhaseAdvancers Static Capacitors bank 16

17. SWITCHED CAPACITOR
 It is suited for centralized power factor correction in applications where plant
loading is constantly changing, resulting in the need for varying amounts of
reactive power.
 An advanced microprocessor based reactive power controller measures plant
power factor via a single remote current transformer (included), and
switches capacitor modules in and out of service to maintain a user-selected
target power factor.
 Typically applied at service entrance or near fluctuating loads.
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18. 18
SWITCHED CAPACITOR

19. SYNCHRONOUS CONDENSER
 Synchronous condenser is a salient pole synchronous generator without
prime mover.
 Synchronous condenser stabilizes power system voltage by supplying reactive
power to the power system and Use for power factor correction.
 It is more economical than capacitors.
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20. Static Var Compensator(SVC)
 The Static Var Compensator (SVC) is a shunt device of the Flexible AC
Transmission Systems (FACTS) family using power electronics to control
power flow and improve transient stability on power grids .
 When system voltage is low, the SVC generates reactive power (SVC
capacitive). When system voltage is high, it absorbs reactive power (SVC
inductive).
 The variation of reactive power is performed by switching three-phase
capacitor banks and inductor banks connected on the secondary side of a
coupling transformer.
 Each capacitor bank is switched on and off by three thyristor switches (Thyristor
Switched Capacitor or TSC). Reactors are either switched on-off (Thyristor
Switched Reactor or TSR) or phase-controlled (Thyristor Controlled Reactor or
TCR).
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21.  Static VarCompensator(SVC)
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22. static synchronous compensator (STATCOM)
 A static synchronous compensator (STATCOM), also known as a static
synchronous condenser (STATCON), is a regulating device used on
alternating current electricity transmission networks.
 It is based on a power electronics voltage-source converter and can act as
either a source or sink of reactive AC power to an electricity network. If
connected to a source of power it can also provide active AC power.
 It is a member of the FACT family of devices. It is inherently modular and
electable.
 These compensators are also usable to reduce voltage fluctuations.
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23. Difference between SVC and STATCOM
 The response time of a STATCOM is shorter than that of a SVC and the
harmonic emission is lower.
 The STATCOM also provides better reactive power support at low AC voltages
than an SVC.
 STATCOMs exhibits constant current characteristics when the voltage is low
under the limit. In contrast the SVC's reactive output is proportional to the
square of the voltage magnitude.so stability decrease.
 STATCOMs typically exhibit higher losses and may be more expensive than
SVCs.
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25. Modulated power filter capacitor compensator
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26. Modulated power filter capacitor compensator
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27. DETERMINING CAPACITOR VALUE
Example
• Power Factor1=74%
• Actual Power=594 kw
• Interested to boost up=97% ,Power Factor2=97%
• Power Factor=KW/KVA
• CosØ1 = kW / kVA
• Ø1= 𝑐𝑜𝑠−1
(PF1) =𝑐𝑜𝑠−1
(74%) =42.27
The reactive power was about:
• TanØ1 = kVAr / kW
• kVAr = 594 kW x tan (42.27) = 540 kVAr
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28. If the power factor were increased to 97%, the reactive power would be about:
• CosØ2 = kW / kVA
• Ø2= Cos-1 (PF2) = Cos-1 (97%) = 14.07
• kVAr = 594 kW x tan (14.07) = 149 kV
• Thus, the amount of capacitance required to boost power factor from 74% to 97% :
• 540 kVAr – 149 kVAr = 391 kVAr
 So I recommended 400kVAR
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29. Economics of power factor improvement
 For Maximum saving, power factor
cosØ2 = 1 − (𝑌/𝑋)2
 X is the rate of charge per kVA of maximum demand per annum
 Y is the rate of charge per kVAR of the power factor correction equipment per
annum
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30. Economical comparison of increasing the
power supply
 Y≤X×
(cosØ2−cosØ1)
sin(Ø2
−Ø1)
 X is the annual cost per kVA of generating plant.
 Y is the annual cost per kVAR rating of power factor correction equipment.
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31. Conclusion
 We should buy electrical equipment as per our load requirement.
 We should optimize between fixed charges and operating charges for
purchase of electrical equipment.
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32. Questions
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33. Thank you
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