FACTS devices are power electronic systems that provide control of AC transmission system parameters to improve power transfer capability and grid stability. FACTS stands for Flexible Alternating Current Transmission System and includes static equipment like STATCOMs. FACTS devices are classified as series controllers that inject voltage and shunt controllers that inject current. They are used to control impedance, voltage, current and phase angle to enhance controllability, reliability and power quality on transmission lines. While expensive, FACTS provide benefits like increased transmission capacity, damping of oscillations and improved stability.

1. FACTS DEVICES
REPRESENTED BY:
MOHAMMED ROHET IMRAN
ROLL NO. 1604-14-734-012
BE: IV/IV, ELECTRICAL ENGINEERING DEPARTMENT.
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2. DEFINITION
• FACTS is defined by the IEEE as “a power electronic based system and other
static equipment that provide control of one or more AC transmission system
parameters to enhance controllability and increase power transfer capability”.
• According to Siemens “FACTS Increase the reliability of AC grids and reduce
power delivery costs. They improve transmission quality and efficiency of power
transmission by supplying inductive or reactive power to the grid”.
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3. WHAT DOES FACTS STAND FOR?
The Abbreviation of FACTS is Flexible Alternating Current Transmission System.
A flexible alternating current transmission system
(FACTS) is a system composed of static equipment used in the transmission of
electrical energy ,it is generally a power electronic device.
General representation of FACTS devices is ,
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4. PURPOSE
• FACTS devices are used to increase power transfer capability of the transmission
line.
• They are also used to enhance controllability of the network.
• To improve the reliability of the system.
• To control the various electrical parameters like series impedance,shunt
impedance, current, voltage and phase angle.
• To increase quality of supply.
• To increase stability of system.
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5. FACTS DEVICES ARE CLASSIFIED AS
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6. OPERATION OF SERIES AND SHUNT
CONTROLLER
• Series Controller :The series controller could be a variable impedance or a
variable source both are power electronics based. In principle, all series
controllers inject voltage in series with the line.
• Shunt Controller :The shunt controllers may be variable impedance connected
to the line voltage causes a variable current flow hence represents injection of
current into the line.
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7. OPERATION OF SERIES-SERIES AND SERIES-
SHUNT CONTROLLER
• Series-Series Controllers: The combination could be separate series
controllers which are coupled via DC POWER LINK .In General all the series
controllers inject Voltage in series with the line.
• Series-Shunt Controllers: The combination could be separate series and
shunt controllers which are coupled via DC POWER Link. In General all the
Series –Shunt controllers inject Voltage and Current in the line.
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8. STATCOM-STATIC SYNCHRONOUS
COMPENSATOR
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9. OPERATION OF STATCOM
• A synchronous compensator is technically a synchronous machine .
• By controlling the field current of the synchronous machine , any amount of
positive or negative reactive power can be injected into the system.
• It consists of battery and voltage source converter connected in Parallel through a
transformer.
• It is capable of Generating and Absorbing Reactive Power when it is fed from DC
energy Source.
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10. ADVANTAGES OF FACTS CONTROLLERS
• Provides secure and controllable tie line connection with neighbouring utilities.
• Increased flexibility
• Improved stability
• Increases the loading capability of lines to their thermal limits.
• Damps out power system oscillations.
• Improves the power quality
• Reduced maintenance cost
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11. DISADVANTAGES OF FACTS CONTROLLERS
• They are expensive.
• Operation is complicated.
• Precise and rapid control of voltage is not possible.
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12. REFERENCES
• [1] Y. N. Yu, Electric Power System Dynamics. Academic Press, 1983.
• [2] P. W. Sauer and M. A. Pai, Power System Dynamics and Stability. Prentice Hall, 1998.
• [3] J. R. Smith, G. Andersson, and C. W. Taylor, “Annotated Bibliography on Power System
Stability Controls: 1986- 1994”, IEEE Trans. on PWRS, 11(2)(1996), pp. 794–800.
• [4] N. G. Hingorani and L. Gyugyi, Understanding FACTS: Concepts and Technology of
Flexible AC Transmission Systems. New York: IEEE Press, 2000.
• [5] N. G. Hingorani, “FACTS-Flexible AC Transmission System”, Proceedings of 5th
International Conference on AC and DC Power Transmission-IEE Conference Publication
345, 1991, pp. 1–7.
• [6] N. G. Hingorani, “Flexible AC Transmission”, IEEE Spectrum, April 1993, pp. 40–45.
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13. THANK YOU
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