Basics of FACTS , STATCOM Explained

1. DEPARTMENT OF ELECTRICALENGINEERING
MALVIYA NATIONAL INSTITUTE OF TECHNOLOGY, Jaipur
A
Presentation
On
STATCOM
Submitted by:
Mayank Sharma
2015UEE1372
Submitted to:
Dr. K.R. Niazi
Professor

2. Contents
 Objective
 FACTS
 Introduction to STATCOM
 Basic Principle of STATCOM
 Operation of STATCOM
 Control of STATCOM
 Comparison of STATCOM with synchronous
condenser(SC)
 Conclusion
 References

3. Objective
In modern electric power systems basic requirements
are
 Reliability
 Flexibility
 Fast response
 Accuracy
Solution: FACTS

4. Flexible AC Transmission Systems
AC transmission systems incorporating power
electronic based & other static controllers to :
 Enhance controllability
 Enhance usable capacity of transmission lines.
FACTS Controllers can be divided into four
categories:
1) Series Controllers
2) Shunt Controllers
3) Combined series-shunt Controllers
4) Combined series-series Controllers

5. Introduction to STATCOM
 Earlier :: Static Var (SVR)– generate or absorb reactive
power (Q) by synchronously switching capacitor and
reactor banks.
 In STATCOM we use power electronics converter to
produce reactive power without reactive energy storage
components by circulating alternating current among
the phase of AC system.
 mostly used in power system for improving quality of
power transmitted form source to load.

6. Introduction to STATCOM
 Control of reactive
power by---DC to AC or
AC to DC switching
converter.
 No internal energy
storage element is used.
 Coupling Transformer –
to match the bus voltage
with converter voltage.

7. COMPONENTS of STATCOM
 Coupling Transformer
 Voltage source
converter
 Capacitor bank
 STATCOM controller

8. BASIC PRINCIPLE
 Reactive current
 Corresponding reactive
power
 By controlling the
excitation of the
machine (E) reactive
power flow can be
controlled

9. BASIC PRINCIPLE
Basic principle is similar to that of synchronous
condenser i.e
 E >V (i.e over excitation) results in leading current,
M/C act as capacitor
 E <V (i.e under excitation) results in lagging current,
M/C act as inductor
 To compensate the mechanical and electrical losses, a
small amount of real power of course flows from the
AC system to M/C
 Controlling E leads to control of Q which further
controls the bus voltage (V)

10. Operation
 From DC i/p voltage source,the
converter produces controllable 3
phase o/p voltage of power system
frequency.
 By varying this o/p voltage (Vo) the
reactive power flow is controlled
 If Vo>V current flow through tie
reactance from converter to AC
system hence converter generates
reactive power for the ac system.
 If Vo=V than Q=0

11. Operation
 If Vo<V current flow
through tie reactance
from AC system to
converter hence
converter absorbs
reactive power.
 Practical converter used
for STATCOM are
1. 1 phase H bridge inverter
2. 3 phase 2 level inverter
3. Multi pulse inverter

12. Operation
 STATCOM can be
operated for
independent control of
real and reactive power
i.e. it can be operated in
4 quadrant operation.
 To exchange real power
phase shift between Vo
and V is made.

13. CONTROL OF STATCOM
 The gating commands
are generated by internal
converter control to
operate the converter
power switches.
 Reference signal
provided by system
control for functional
operation.

14. STATCOM Connection in power system

15. Comparison
Synchronous Condenser(SC)
 In SC rotation of DC field
winding results in generation
of AC voltage
 O/p contains harmonics
STATCOM
 Synchronous operation of
the switches results in AC
o/p voltage
 O/p contains harmonics but
some methods can be used
to eliminate them (PWM,
multi pulse inverter,multi
level inverter etc.)

16. The Advantage Of a STATCOM Over a SC
1. The response is much faster to changing system
condition.
2. Does not contribute to short circuit current.
3. No moving parts . Easy maintenance.
4. No loss of synchronism.

17. CONCLUSION
 STATCOM HAVE FAST AND DYNAMIC PERFORMANCE-
hysteresis current control scheme
 VARIOUS CONTROL STRATEGY INVOLVED
 HARMONIC ELIMINATION- STATCOM-BESS control system
 Power electronic devices used- losses can be minimized
Hence power system can be made Reliable,Flexible,Fast,Accurate
using STATCOM.

18. REFERENCES
• NPTEL Lectures
• A Minimal Harmonic Controller for a STATCOM Ben-Sheng
Chen and Yuan-Yih Hsu, IEEE Transactions On Industrial
Electronics,vol.55,no. 2, February 2008
• Current Control ofAngle Controlled STATCOM
Zhengping Xi, Student Member, IEEE, and Subhashish
Bhattacharya, ember, IEEE, 2007 39th North American
Power Symposium (NAPS 2007)
• A Decoupling-Controlled STATCOM For Power Quality
Improvement Of Impact Loads Chunpeng Zhang, Qirong
Jiang, Luyuan Tong