The significance of power factor correction (PFC) has long been visualized as a technology requirement for improving the efficiency of a power system network by compensating for the fundamental reactive power generated or consumed by simple inductive or capacitive loads. With the Information Age in full swing, the growth of high reliability, low cost electronic products have led utilities to escalate their power quality concerns created by the increase of such “switching loads.” These products include: entertainment devices such as Digital TVs, DVDs, and audio equipment; information technology devices such as PCs, printers, and fax-machines; variable speed motor drives for HVAC and white goods appliances; food preparation and cooking products such as microwaves and cook tops; and lighting products, which include electronic ballasts, LED and fluorescent lamps, and other power conversion devices that operate a variety of lamps. The drivers that have resulted in this proliferation are a direct result of the availability of low-cost switch-mode devices and control circuitry in all major end-use segments: residential, commercial, and industrial.

1. A
Seminar
On
“POWER FACTOR IMPROVEMENT
USING UPFC”

2. Content
 Introduction of power factor improvement
 Power factor
 Effect of low power factor
 FACTS
 Benefits of FACTS
 FACTS Devices
 Introduction to UPFC
 Circuit description
 Operation of UPFC
 Application
 Conclusion

3. INTRODUCTION
 Electrical energy generated, transmitted,
distributed in the form of alternating current.
Therefore power factor plays an important role.
 Power factor is highly undesirable as it causes
an increase in current, result in additional losses
of active power in all the elements of power
system
 For good quality of power supply, it is necessary
to have power factor as close as unity.

4. Power factor
The cosine angle between voltage and current in an AC
circuit.
The ratio of resistance to impedance.
The ratio of active power to the apparent power.
 Power triangle
Kw
KVA
KVAr
q
θ
• Apparent power= VI in KVA
• Active power = VI cosθ in KW
• Reactive power = VI sinθ in KVAr

5. Effect of low power factor
Large KVA rating of equipment
Greater conductor size
Large copper losses
Poor voltage regulation

6. FACTS
Flexible AC Transmission System (Facts) is a new
integrated concept based on power electronic switching
converters and dynamic controllers to enhance the
system utilization and power transfer capacity as well as
the stability, security, reliability and power quality of AC
system interconnections.
FACTS technologies improved transmission system
operation with minimum investment, environmental
impact and implementation time compared to the
construction of new transmission line.

7. BENEFITS OF FACTS
 Regulation of power flows in prescribed transmission routes.
 Reduces the need for construction of new transmission lines,
capacitors and reactors.
 Provides greater ability to transfer power between controlled
areas.
 These devices help to damp the power oscillations that could
damage the equipment.

8. BENEFITS OF FACTS
 Improves the transient stability of the system.
 Controls real and reactive power flow in the line
independently.
 Damping of oscillations which can threaten security or limit
the usable line capacity.

9. FACTS Devices
Name Type Main function Controller
SVC shunt voltage control Thyristor
TCSC series power flow control Thyristor
TCPAR series & power flow control Thyristor
shunt
STATCOM shunt Voltage control GTO
SSSC series power flow control GTO
UPFC shunt & voltage and power GTO
series flow control

10. INTRODUCTION TO UPFC
 The UPFC concept describe in 1995 by L. Gyugyi.
 The UPFC is a device which can control simultaneously all three
parameters of line power flow
 Such "new" FACTS device combines together the features of two
"old" FACTS devices:
1. STATCOM
2. SSSC
 Control active and reactive power in transmission line
 These two devices are two Voltage Source Inverters (VSI’s)
connected respectively in shunt with the transmission line through a
shunt transformer and in series with the transmission line through a
series transformer, connected to each other by a common dc link
including a storage capacitor.

11. CIRCUIT DESCRIPTION
 The basic configuration of a UPFC, which is installed
between the sending-end Vs and the receiving-end VR. The
UPFC consists of a combination of a series device and a
shunt device, the dc terminals of which are connected to a
common dc link capacitor .
Fig1: Basic configuration of UPFC

13. Operation of UPFC
 Series inverter- used for active and reactive line power flow
 Shunt inverter used for voltage regulation
 UPFC extensively used in power system because of their
ability to provide flexible power flow controller

14. Application
 Using HVDC transmission system
 Use of UPFC for optimal power flow control
 For improving micro grid voltage profile
 For enhancement of voltage profile & minimization of losses
 Increase transient stability of inter area power system
 For damping power system ossicilation

15. conclusion
UPFC is FACT device used to control active &
reactive power flow. The overall result over the
power system is that it improved the power factor.
So it bring the present power system at better
economy level

16. Thank you