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2. Presented By
A
supervisor
Dr.

3. Outlines
1. Introduction on facts (problem and solution) .
2. Statcom .
3. Simulation results based on Matlab/Simulink.
4. Svc .
5. Svc and statcom .
6. Simulation results based on Matlab/Simulink.

4. Project introduction
 Problem Definition
Modern Power Transmission networks are becoming increasingly stressed due to growing
demand and restrictions on building new lines. Losing stability is one of the major threat of
such a stressed system following a disturbance.
Solutions
Flexible ac transmission system (FACTS) devices are found to be very effective in a
transmission network for better utilization of its existing facilities without sacrificing the
desired stability margin and the filters are found to be very effective in a transmission
network for better power quality

5. Types of FACTS
Series shunt
Series-
Series
Shunt
Series
FACTS
 SSSC
 TCSC
 TCSR
 TSSC
 SVC
 STATCOM
 TCR
 TSC
 TSR
 UPFC  IPFC

6. Objectives of FACTS
To increase the power transfer capability of transmission systems.
To Keep power Flow over designated routes.
Secure loading of transmission lines nearer to their thermal limits.
Prevention of cascading outages by contributing to emergency control.
Damping of oscillation that can threaten security or limit the useable line capacity.

7. Facts controllers
 Definition
They are the power electronics based circuit that control the power flow of ac
transmission system
Why we use them ?
In past mechanical circuit breakers like relays were used to control power
flow and they were not suitable as they cant compensate the power loss due to
reactive power of transmission system which facts can do very well

8. Classification of facts controllers
 first classification based on power electronic devices used in the
control :
1) variable impedance type (ex.svc , tcsc)
2) vsc based (voltage source converter)
Ex. Statcom ,upfc,sssc

9. Following
-Second classification based on connection of the
controller :
-1) shunt connected controller(ex. Svc , statcom)
-2) series connected controller (ex.tcsc,sssc)
-3) hybrid controller ( upfc)

10. Shunt controller
Power system is connected in shunt with the facts , there are 2 types of

11. Following

12. Following

13. Proposed System(simulink discussion of statcom)
• The power grid consists of two
• (source 1) has a rating of 2100 MVA, representing 6 machines of 350 MVA .
• (source2) has a rating of 1400 MVA, representing 4 machines of 350 MVA.
• The generation substation M1 is connected to this load by two transmission lines L1 and
L2250 MW Load centered at Bus 1 , 50 MW Load centered at Bus 3 and 100 MW Load
centered at Bus 4
• The generation substation M2 is also connected to the load by a 50-km line (L3).

14. Proposed System based on matlab/simulink
The proposed system is modeled and
simulated with three phase short circuit at
time equal 3.2 sec then cleared after 10
cycles.
 Main Factors affected by
the fault:
 Rotor speed
 Rotor angle
 Bus voltage
 Active power
 Reactive power

15. Case 1: Results without FACTS
Pre- fault Post –fault clearance
To study the transient stability three phase short circuit is applied to the system at time
equal 3.2 sec then cleared after 10 cycles. The simulation results in after the fault
occurred the system lose its synchronism
Post –fault clearance
Pre- fault
Rotor angle deviation
Rotor speed

16. Cont. ….. Case 1:results without FACTS
the generator the is improved and regain to the synchronism
excitation voltage
Pre- fault Post –fault clearance

17. Cont. … Case 1:results without FACTS
The simulation results in after the fault occurred the system lose its synchronism
Post –fault clearance
Post –fault clearance
Pre- fault
Pre- fault

18. Proposed FACTS For Improvement Study
Static VAR Compensator (SVC).
Static Synchronous Compensator (STATCOM).
STATCOM&SVC

22. Case 5: Static VAR Compensator (SVC).
 Operation and Control
The primary purpose is usually for rapid control of voltage at weak points in a network.
Installations may be at the midpoint of transmission interconnections or at the line ends.
Static Var Compensators are shunt connected static generators and or absorbers whose
outputs are varied so as to control voltage of the electric power systems. In its simple form
SVC is connected of FC-TCR configuration, The SVC is connected to a coupling
transformer that is connected directly to the ac bus whose voltage is to be regulated. The
effective reactance of the FC-TCR is varied by firing angle control of the anti-parallel
thyristors. The firing angle can be controlled through a PI controller in such a way that the
voltage bus where the SVC is connected is maintained at the reference value.

23. Cont. ….. Case 5: SVC
 Benefits
Voltage support, and regulation.
Transient stability improvement.
Power system oscillation damping.
Reactive power compensation.
Power transfer capacity increase
and line loss minimization.
Filter harmonics
Improved Factors
Voltage
Rotor speed
Rotor angle

24. simulink Case 5: SVC

25. Cont. …. Case 5: SVC

26. Cont. … SVC


28. Case 10: STATCOM
 Definition
Static Synchronous Compensator is a power electronic device using force commutated devices like
IGBT, GTO etc. to control the reactive power flow through a power network and thereby increasing
the stability of power network. It is connected in shunt with the line. it can either absorb or generate
reactive power in synchronization with the demand to stabilize the voltage of the power network.
Purpose
 Voltage regulation and compensation
of reactive power.
 Correction of power factor.
 Elimination of current harmonics
Modes of operation
Voltage control
VAR control

29. Static synchronous compensator(STATCOM)
In steady state operation, the voltage V2 generated by the VSC is in phase with
V1 (δ=0), so that only reactive power is flowing (P=0). If V2 is lower than V1 ,
Q is flowing from V1 to V2 (STATCOM is absorbing reactive power).
On the reverse, if V2 is higher than V1, Q is flowing from V2 to V1
(STATCOM is generating reactive power). The amount of reactive power is
given by
Q = (V1(V1 – V2)) / X
A capacitor connected on the DC side of the VSC acts as a DC voltage source.
In steady state the voltage V2 has to be phase shifted slightly behind V1 in order
to compensate for transformer and VSC losses and to keep the capacitor
charged.
STATCOM circuit diagram

30. Static synchronous compensator(STATCOM)
Dynamic Response

31. Cont. …. Case :10 STATCOM
 Transient Response
Post- fault clearance Post- fault clearance
Pre- fault
Pre- fault
Reactive power at all buses Active power at all buses