1. UPQC a novel method to
efficiently utilize Sustainable /
Alternate Energy Sources
AJAL.A.J
Assistant Professor –Dept of ECE,
UNIVERSAL ENGINEERING COLLEGE
MAIL: ec2reach@gmail.com Mob: 8907305642
PSERC
5. ELECTRONIC SOLUTIONS
FOR POWER CONDITIONING
Inject series voltage for
phase control / exchange
energy between phases
Back - to - back
rectifier / DC link /
inverter
Shunt positioning in system to inject
current
PSERC
6. What is Power quality ?
Definition : “Power quality problem is any power problem manifested
in voltage, current, or frequency deviation that results in failure or
misoperation of customer equipment”.
Power quality can be simply defined as shown in the interaction
diagram:
•Voltage Sags
•Voltage Swells
•Blackouts/Brownout
s
•Transient
Voltage
Quality
Current
Quality
•Flickering
•Waveform Distortion
Power
Quality
•Arc Type
•Temporal
•Converter Type
•Inrush
•Overcurrent
•Harmonics
Electrical Grid
Utility
Nonlinear Loads
Industrial/Commercial/Residential
Consumers
•Saturation Type
•NLL-Analog/Digital
Switching
6
7. What causes power quality
problems?
• Internal factors: faults o
lightning strikes on
transmission lines or
distribution feeders,
equipment failures etc
External factors: Transformer energisation. Capacitor or feeder
switching, Power electronic loads, Arc furnace and induction heating systems
switching on or off of large loads etc.
8. Why are we concerned about PQ
All nonlinear and time varying temporal type electric loads fall
generally in two wide categories, namely the analog arc
(inrush/saturation) type and digital converter (power electronic)
switching type.
Key Problems:
1.
2.
3.
4.
5.
6.
7.
Damage to sensitive equipment
Interference
Malfunction
Extra losses
Personnel Safety issues
Poor Utilization
Poor Power Factor.
8
9. power quality audit of a business?
• Does the facilities wiring and grounding meet
code and
more impor tantly is it adequate to meet their
power needs from a power quality stand
point ?
• What is the quality of the ac voltage supplying
the
equipment
?
11. Voltage Power Quality Problems
•
•
•
•
•
•
•
•
•
Voltage Sag
Voltage Swell
Voltage Interruption
Under/ Over Voltage
Voltage Flicker
Harmonic Distortion
Voltage Notching
Transient Disturbance
Outage and frequency variation
12. Current Based Power Quality
Problems
• Reactive Power Compensation
• Voltage Regulation
• Current Harmonics Compensation
• Load Unbalancing (for 3-phase systems)
• Neutral Current Compensation (for 3-phase
4-wire systems)
14. Two Main Power Quality
Problems
Harmonics and Reactive current drawn
by the loads.
Voltage Sag,Swell,Unbalance etc.
15. Power Electronic Controllers in Utility
Systems
SOLID-STATE
BREAKER
SENSITIVE
LOAD
SOLID-STATE
CURRENT LIMITER
COMPENSATED
VOLTAGE, POWER FACTOR
HARMONICS,
DSTATCOM
REDUCED
SAGS, TRANSIENTS,
HARMONICS
ENERGY
STORAGE
DYNAMIC
NON-LINEAR
LOAD
DVR
SENSITIVE
LOAD
ENERGY
STORAGE
UNINTERRUPTED
SUPPLY
SSTS
CRITICAL
LOAD
16.
17. Characterization Methods .
Broad Categories
Transients
Short duration
voltage variation
Specific Categories
Impulsive
Oscillatory
Sag
Swel
Interruption
Under voltage
Long duration
voltage variation
Over voltage
Voltage Unbalance
Waveform distortion Harmonics
Notching
Voltage Flicker
23. Solution of Harmonic Mitigation
Using Power Filters
Passive Filters
Active Filters
Shunt
Shunt
Series
Series
Hybrid
Hybrid
UPQC
Hybrid Filters
Several Combinations
are possible for hybrid
of active and passive
26. Distribution Voltage Restorer (DVR)
Functions
Reactive Power Compensation
Voltage Regulation
Compensation for Voltage sag
and Swell
Unbalance Voltage Compensation
(for 3-phase systems)
31. Unified Power Quality Compensator
(UPQC)
Functions
Reactive Power Compensation
Voltage Regulation
Compensation for Voltage sag and swell
Unbalance Compensation for current and voltage (for 3-phase
systems)
Neutral Current Compensation (for 3-phase 4-wire systems)
32. UPQC ? ? ?
UPQC stands for Unified Power Quality Conditioner.
UPQC is an active series / shunt power line conditioner.
• It is used to compensate power quality issues such as
Voltage sags, swells, Voltage imbalance, flicker,
harmonics and reactive current.
• It is a combination of a STATCOM as well as a series
compensating stage connected before the load in
series with the power network using a matching
transformer.
33. Functions - UPQC?
• Load voltage regulation be series voltage injection
• Dynamic current Injection for reactive power
compensation
UPQC is used to compensate voltage sags and
current harmonics, control input power factor near
to unity as well as to regulate the load voltage. It can
be installed by the electric utilities to damp out
harmonic propagation caused by resonance with line
impedance and passive shunt compensators.
34. Basic topology of UPQC ?
• UPQC consists of 1 x 3 phase and 3 x 1 phase Voltage source
converters sharing the same capacitive DC link.
• The 3 phase converter will act as an Active Filter while the
other is a series filter (Dynamic Voltage Regulator)
54. Future Trends
New Developed Power Semiconductor Switch
Combines the best performance Characteristics
of IGBT and IGCT
=
+
IGBT
IGCT
ETO
Emitter Turn-Off (ETO) Thyristor
55. Conclusions
A Balanced and Cautious Application
The acceptance of the new tools and technologies will take time,
due to the computational requirements and educational barriers.
The flexibility and adaptability of these new techniques indicate that
they will become part of the tools for solving power quality
problems in this increasingly complex electrical environment.
The implementation and use of these advanced techniques needs
to be done with much care and sensitivity. They should not
replace the engineering understanding of the electromagnetic
nature of the problems that need to be solved.
55
56.
G. J. Porter and J. A. V. Sciver, “Power Quality Solutions: Case Study for
Troubleshooters”, Fairmont Press, Inc., 1999.
J. Arrillaga, N. R. Watson and S. Chen, “Power System Quality Assessment”,
John Wiley & Sons, Inc., New York, 2000.
M. H. J. Bollen, “Understanding Power Quality Problems”, Standard Publishers
Distributors, First Indian Edition, 2001, Delhi.
J. Schlabbach, D. Blume and T. Stephanblome, “Voltage Quality in Electrical
Power Systems, 2001, U. K. ISBN 0-85296-975-9.
IEEE Guide for Application and Specification of Harmonic Filters, IEEE
Standard 1573, 2003.