maximise efficiency & reliability - maintain ‘healthy’ electrical network with harmonic-less
TRANSCRIPT
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Maximise Efficiency & Reliability: Maintain ‘healthy’ electrical network with harmonic-less
Ch’ng Eng Yong, CEng MEI, CEM, CMVP, PEM
July 2016
Schneider Electric 1
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What are we discussing today
● Solve the harmonic issue, if possible, starting from the root of the problem.
●A cost effective solution requires the knowledge of the
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●A cost effective solution requires the knowledge of the electrical power system and it is often a combination of several solutions.
●Harmonic mitigation solutions are available in market to fulfill your needs.
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Agenda
●Why is there harmonic in the electrical network?
●General waveform signature (IEC 61000-3-6)
●Typical harmonic mitigation solutions
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●Typical harmonic mitigation solutions
●Solutions comparison
●What’s next?
●Conclusion
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Why is there harmonic in the electrical network?
●Look at the full-bridge rectifier schematic
●Diode forward bias: ●Anode is more positive than cathode ●DC bus voltage is less than supply voltage
DC bus voltage U
DC bus iC
U
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iC
DC bus capacitor
current (I C)
Supply voltage (V)
Supply current
(i)
V = E - Zsi
iC
i
V
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Why is there harmonic in the electrical network?
iC
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Vc
-Vc
t
ei
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Agenda
●Why is there harmonic in the electrical network?
●General waveform signature (IEC 61000-3-6)
●Typical harmonic mitigation solutions
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●Typical harmonic mitigation solutions
●Solutions comparison
●What’s next?
●Conclusion
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General waveform signature (IEC 61000-3-6)
CurrentType of Load Typical Waveform Distortion
Single Phase 80%Power Supply (high 3rd)
high 2nd, 3rd,Semiconverter 4th at partial
loads
6 Pulse Converter,capacitive smoothing, 80%no series inductance
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
-0.5
0.0
0.5
1.0
Current
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no series inductance
6 Pulse Converter,capacitive smoothing 40%
with series inductance > 3%,or dc drive
6 Pulse Converterwith large inductor 28%
for current smoothing
12 Pulse Converter 15%
AC Voltage varies withRegulator firing angle
FluorescentLighting 17%
0 10 20 30 40-1.0
Time (mS)
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
0.0 10.0 20.0 30.0 40.0-1.000
-0.500
0.000
0.500
1.000
Time (mS)
Current
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
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Typical harmonic mitigation solutions
●Equipment based solutions●DC/AC choke●Passive filter●Drive isolation transformer (DIT)●Multi-pulse VSD
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●Multi-pulse VSD●Active front end (AFE)●C-less technology
●System based solutions●Passive filter (Tuned power factor correction)●Phase shifting transformer●Zero-sequence harmonic filter●Active harmonic filter
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Harmonic mitigation solutions
I. DC/AC Line Chokes
II. Passive Filters
III. Zero-Sequence Harmonic Filter
IV. Drive Isolation Transformer (DIT)
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V. Phase Shifting Transformer
VI. Multi-pulse VSD (12, 18, 24, …)
VII. Active Harmonic Filters (AHF)
VIII. Active Front End (AFE)
IX. C - Less Technology
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DC choke & line choke (installation)
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DC choke & line choke (performance)
●Effect of the choke: dt
diLVL =
0.0
0.5
1.0
Current
0.0
0.5
1.0
Current
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Line current spectrum
1.211.54
4.51
6.77
12.36
15.32
20.77
22.88
25.16
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
Without additional choke
THDI = 100%Line current spectrum
9.38
3.201.80
0.87 0.74 0.49 0.35 0.30
25.94
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
With additional choke 3%
THDI = 40%
With additional large choke (>5%)
0 10 20 30 40-1.0
-0.5
Time (mS)
Current
THDI = 30%Line current spectrum
1.211.54
4.51
6.77
12.36
15.32
20.77
22.88
25.16
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
Without additional choke
THDI = 100%Line current spectrum
9.38
3.201.80
0.87 0.74 0.49 0.35 0.30
25.94
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
With additional choke 3%
THDI = 40%
With additional large choke (>5%)
0 10 20 30 40-1.0
-0.5
Time (mS)
Current
THDI = 30%
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DC choke vs. line choke
● Influence of the nature of reactors ● In terms of harmonics, the results are quite similar.●DC bus choke is a little smaller and the voltage drop is lower.
Inductor 2mH in the DC busLine inductor 3 x 1mH Inductor 2mH in the DC busLine inductor 3 x 1mH
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9,38
3,201,80
0,87 0,74 0,49 0,35 0,30
25,94
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 39.16 %
6,65
4,142,23 1,73 1,39 1,12 0,99 0,81
25,80
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 35.54 %
ChokeACChokeDC 3 =
9,38
3,201,80
0,87 0,74 0,49 0,35 0,30
25,94
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 39.16 %
9,38
3,201,80
0,87 0,74 0,49 0,35 0,30
25,94
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 39.16 %
9,38
3,201,80
0,87 0,74 0,49 0,35 0,30
25,94
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 39.16 %
6,65
4,142,23 1,73 1,39 1,12 0,99 0,81
25,80
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 35.54 %
6,65
4,142,23 1,73 1,39 1,12 0,99 0,81
25,80
0
5
10
15
20
25
30
1 3 5 7 9 11 13 15 17 19 21 23 25
Harmonic order
I (A
)
THDI = 35.54 %
ChokeACChokeDC 3 =
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DC choke & line choke (practical considerations)
● Most cost effective solution (0-20% of drive cost).
● Reduce THDI around 30 - 50%.
● Bulky and heavy.
● Proper ventilation.
Advantages Concerns
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● Reduce THDI around 30 - 50%.
● Line chokes protects the drive front end, limits voltage spikes and short circuit current.
● Depending on load condition, might not be able to meet standard requirements.
● Voltage drop ( >5%) can affect low line supply conditions. Lowers torque performance at full speed when voltage drop is higher.
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Passive filter (tuned PFC)
●Two type of passive filter● Load based passive filter● Global passive filter
●Load based passive filter ● Designed & sized based on the load size (kW)
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● Designed & sized based on the load size (kW)● Operate when the connected load is in operation
●Global passive filter● Designed & sized based on the system power factor requirements.● Compensation is based on required kVAR (PF) in the system.● Primary function: Harmonic filtering● Secondary function: Power factor correction● Different from Detuned Power Factor Correction (reverse role)
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Passive filter – load based (performance)
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With simple choke THDI 48% With passive filter THDI 10%With simple choke THDI 48% With passive filter THDI 10%
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Global passive filter
●Don’t confuse with detuned Power Factor Correction (PFC)●Detuned tuning point is typically outside -8% of target harmonic order ● a.k.a. Anti-Resonant PFC●Primary function: PFC●Secondary function: Harmonic filtering (side-effect) – Not that effective
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●Tuned/Passive harmonic filter PFC●Tuned tuning point is typically within -8% of target harmonic order ●Cannot fully compensate the according to harmonic.
●Both PFC’s activation based on displacement power factor
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Power factor – which component?
Power factor in system with linear loads only.
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P = kW (Real Power)
D = kVAH
(Distortion Power)
Q = kVAr (Reactive Power)
S = kVA (Apparent Power)
θTPF (True/Total Power Factor)
Power factor component in system with harmonics (linear + nonlinear loads)
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Power factor components in system with harmonics
D = kVAH
(Distortion Power)
Q = kVAr (Reactive Power)
S = kVA (Apparent Power)
θTPF (True/Total Power Factor)
( )
22
1
22
222
11
kkk
rmsrms
THDTHDIV
IV
IV
DQPkVAS
rmsrms
++=
=
=++=
∑∞
=
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P = kW (Real Power)
(True/Total Power Factor)
221
11
11
11
IV
IV
THDTHDS
THDTHDIVrmsrms
++=
++=
True/Total Power Factor : distPFdispPFTPF θθθ coscoscos ⋅=
Displacement Power Factor (Fundamental Components):
1
cosS
kWdispPF =θ
Distortion Power Factor (Harmonic Components): 22 11
1cos
IV
distPFTHDTHD ++
=θ
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Passive filter (load based)
Advantages Concerns
● Able to reduce THDI to around 5 - 16%.
● Line chokes protects the drive front end, limits voltage spikes
● Bulky and heavy.
● Expensive (50 - 80% drive cost).
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front end, limits voltage spikes and short circuit current.
● Meet IEC 61000 requirements
● Designed for full load capacity to obtain effective impedance.
● Filter capacitor (passive filter) must be disconnected when VSD operates at no load or low load condition. (causing leading PF & voltage regulation concern is remain connected)
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Zero-sequence harmonic filter
● Issue with neutral overloading
Phase A (50 Amps)
Phase B (50 Amps)
Electronic
Loads
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Phase B (50 Amps)
Phase C (57 Amps)
Neutral (82 Amps)
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Zero-sequence harmonic filter
●Typical solution for neutral overloading:●Upsize neutral: “200% Neutral” – 173% maximum current, so provides a
little extra margin ●Concern: All neutral connected components need to be upsized too.
●Zero-Sequence Harmonic Filter
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●Zero-Sequence Harmonic Filter●Installed close to the nonlinear loads (e.g. DB)●Concern: Proper ventilation and bulky
●Active Harmonic Filter●Installed at upstream (Global solutions)●Concern: Expensive and bulky
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Zero-sequence harmonic filter – principle
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Zero-sequence harmonic filter –performance
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Reduction ratio = 1:10
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Drive isolation transformer (DIT)
●Designed with oversized core & special windings
●Can withstand high heat & harsh operational environment
●Electrically isolation secondary (Wye) source from primary (Delta)
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●Secondary source (Wye) is grounded●Prevent transfer of common-mode noise and/or ground current●Reduce transients and surges
●Four Basic Functions:●Voltage change (Delta-Wye windings)●Common-mode noise & impulse reduction●Reduction of drive induced ground currents ●Reduction of drive distortion effects on system voltage
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Drive isolation transformer (DIT)
Advantages Concerns● Trap triplen harmonic order in
delta windings (zero-sequence network)
● Protects the drive front end,
● Bulky and heavy.
● Expensive (50 - 80% drive cost).
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limits voltage spikes and short circuit current.
● Reduce common-mode noise, induced ground current, impulse from either both sides.
● Cannot completely isolate the harmonic (positive-sequence network)
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Phase shifting transformer
●Phase shifting involves separating the electrical supply into two or more outputs.
●Each output being phase shifted with respect to each other with an appropriate angle for the harmonic pairs to be eliminated.
● The concept is to displace the harmonic current pairs in order to bring each to a 180o phase shift so that they cancel each other out.
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180o phase shift so that they cancel each other out.●Positive-sequence currents will act against negative-sequence currents. ● Zero-sequence currents (triplen order) act against each other in a three-phase
system.●An angular displacement of:
● 60o is required between two three-phase outputs to cancel 3rd harmonic currents;● 30o is required between two three-phase outputs to attenuate the 5th and 7th harmonic
current pairs;● 20o is required between two three-phase outputs to cancel the 11th and 13th harmonic
current pairs.
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Phase shifting transformer
30o with respect to
0o with respect to primary
An angular displacement
of 30 o
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( )
−+−≅ ...11
11cos
7
7cos
5
5coscos
321
ttttti
ωωωωπ
ω
5th & 7th harmonics go away!
( )
−−+≅ ...11
11cos
7
7cos
5
5coscos
322
ttttti
ωωωωπ
ω
respect to primary
primary
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Phase shifting transformer
Advantages Concerns
● Protects the drive front end, limits voltage spikes and short circuit current.
● Trap triplen harmonic order in
● Bulky, heavy
● Expensive (100% drive cost)
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● Trap triplen harmonic order in delta windings
● Attenuations of 5th and 7th
harmonic currents with an angular displacement of 30o .
● Both transformers (same rating) have to be loaded equally to achieve optimum harmonic attenuation.
● Transformer must be able to withstand excessive heat due to harmonic current.
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Multi-pulse VSD
●Harmonics can be reduced by phase multiplication.
● If n six-pulse rectifier sections…● have the same transformer ratios,● have transformers with identical impedance's,
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● have transformers with identical impedance's,● are phase shifted exactly 60°/n degrees from each other (where n = set of
rectifiers) or 360o/m (where m = number of pulse)
●Then…● 2 set of rectifier sections phase shifted by 30° result in 12-pulse row up H7
are slightly reduced● 3 set of rectifier sections phase shifted by 20° result in 18-pulse row up to
H13 are slightly reduced
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Multi-pulse VSD – 12 pulse VSD
●12 pulses supply structure ●Using the concept of phase-shifting transformer of 30o
Phase shifted by 30°
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Delta
Star
6 pulsesrectifier
6 pulsesrectifier
M
Inverter
H5 and H7 attenuated
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Multi-pulse VSD – 18 pulse VSD
●18 pulses supply structure ●Using the concept of phase-shifting transformer of 20o
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Multi-pulse VSD – 18 pulse VSD
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Multi-pulse VSD comparison (6, 12, 18 pulse)
● 12-Pulse converter
+
-
DC Bus Load
Delta
Delta
Wye
AC Line
● 18-Pulse converter
A
B
C
DC+
DC-
LineReactor
Rectifier Assembly
TransformerTertiary
MultipulseTransformer
A
BC
1
2
3
4
56
7
8
9
● 6-Pulse converter
DC LinkReactor
M
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Externally mounted 3 winding transformer; more wire and cabling; complicated
Current slightly distorted Ithd 8% to 15% (depending on network impedance)
0
100
A
12 pulse
Large footprint, more steel & copper (losses)
Current wave form goodIthd 4% to 6% (depending on network impedance)
0.0s 0.02s
0
100
A
18 pulse
Tertiary
“C-less” or 3% reactance min (if included); small footprint, simplified cabling
Current waveform distortedIthd 30% to 50% with 3% reactor (depending on network impedance)
0
100
A
6 pulse
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Multi-pulse VSD
Advantages Concerns
● Eliminates rows up to H7,(12p), up to H13(18p)
● Reduces THD(I) down to 10-15%(12p), 5-3%(18p)
● Very Bulky and heavy
● Expensive (100% drive cost)
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10-15%(12p), 5-3%(18p)
● Suppresses line voltage transients
● Efficient on the all load range
● Meet IEC 61000 requirements
● Needs 2 or 3 diodes bridge rectifier
● Needs a specific transformer windings
● More cost effective for high power VSD ( >100kW)
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Active harmonic filter (AHF)
●Leading-edge technology for harmonic filtering● IGBTs, 20 kHz modulation, to synthesize the output current for injection●Real time control algorithms
●Responds instantly to inrush situations (100µs)●Full response in 8 msec for steady sate situations
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●Full response in 8 msec for steady sate situations
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Active harmonic filter – schematic diagram
IGBTs manage the power flow to/from the DC bus caps
decouples the filter board inductor/capacitor circuit from the
AC lines
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three phase AC line connection remove the carrier frequency from
the current waveform sent into the AC lines.
200k AIC
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Active harmonic filter – control block
AC Phase
VdcIGBT Converter
Lext CTi Lin
K1
R1
Cdc
CB
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Load
Notch Filter
SMPS Board
Control Board
Regulation &
Monitoring
Control Signal
CTa
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Active harmonic filter (performance)
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Active harmonic filter (AHF)
Advantages Concerns
● Reduces THD(I) below 5%
● Several units can be installed on the same supply
● Expensive (150% drive cost)
● Reliability (more components)
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● Global solutions
● Resonance elimination
● Corrects displacement power factor (cos θ)
● CT direction & location must be correct
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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Active front end
●The solution use an active rectifier bridge made with IGBTs instead of the standard 6 diodes rectifier.●The rectifier is controlled in order to ‘create’ a sinusoidal current into the
network (THDI <5%)● It has the advantage to reverse the power flow and allows the feedback
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of energy into the network (regenerative mode when the motor slow down or during braking phase).
Current
Voltage
Active Front End
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Active front end – comparison
Current THD (%)
Voltage THD (%)RSC=20
Voltage THD (%)RSC=100
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+ Inductor
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Active front end (AFE)
Advantages Concerns
● Nearly sinus supply (THDI<5%)
● Meet IEC 61000 requirements
● Very expensive if reversibility not needed (150% drive cost)
● Need additional EMC filter
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● Reversible, allows to feedback energy onto the network
● Can be embedded in the drive
● Need additional EMC filter
● Reliability (IGBT, more components)
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Harmonic mitigation solutions
I. DC/AC line chokes
Ii. Passive filters
Iii. Zero-sequence harmonic filter
Iv. Drive isolation transformer (DIT)
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V. Phase shifting transformer
Vi. Multi-pulse VSD (12, 18, 24, …)
VII. Active harmonic filters (AHF)
Viii. Active front end (AFE)
Ix. C - less technology
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C-less technology - principle
●DC bus capacitor value is reduced to 2-3% of standard AC drive capacitor value.
●Current only flows from the mains into the DC link when the mains voltage exceeds that of the capacitor (diode forward bias).
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●The larger the DC link capacitor, the shorter the period of current flow, and the higher the peak current.
A non demanding load like a fan allows 95% reduction of the DC bus capacitance without significant reduction of performances.
Less capacitance --> less current harmonics
Rectifier D C Link Inverter
Thre
ePhase Power C
+
-
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C-less technology – performance comparison
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
0.0
0.5
1.0
Current
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0 10 20 30 40-1.0
-0.5
Time (mS)
Current
0 10 20 30 40-1.0
-0.5
0.0
0.5
1.0
Time (mS)
Current
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C-less technology
Advantages Concerns
● Reduces THD(I) below 35%without added filter
● Meet IEC 61000 requirements
● Only for Fan, Pump and non demanding applications (HVAC)
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● Meet IEC 61000 requirements
● Lowest cost for harmonic mitigation
● More DC bus ripple so more torque ripple.
● More sensitive to network voltage drop and perturbation
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Agenda
●Why is there harmonic in the electrical network?
●General waveform signature (IEC 61000-3-6)
●Typical harmonic mitigation solutions
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●Typical harmonic mitigation solutions
●Solutions comparison
●What’s next?
●Conclusion
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Solutions comparison
●Comparison between harmonic mitigation solutions at drive level
Nil Choke 3%-5%
Passive filter
C less 18 pulses
Active front end
Active filter
Current distortion THDI >80% <48% <5%-16% <30% <5%-10% <5 % <5%
Meet IEEE519 gen. app. no System dependent yes System dependent yes (18p) yes yes
Mitigation solutions
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Meet IEEE519 gen. app. no System dependent yes System dependent yes (18p) yes yesMeet IEC 61000 3-12 no yes yes yes yes yes yesMeet IEC 61000 3-2 no no no no no yes yes
Drop voltage no yes no no no no noPower factor no/full load <0,8 0.75-0.95 0.75-1 0.95 0.90-0.99 1 1Load influence on THDI no yes yes no no no noEfficiency 100% 97% 98% 100% 96% 96% 96%Reliability High High Good Good Medium Good GoodEMC Poor Good Good Medium Good Medium MediumInfluence on VSD perf. no weak no Strong no no noResonance risk no weak yes no no no no
Cost effective very good good <100kW very good >200kW Medium Low harmonicPrice ratio /drive cost 100% 110%-120% 150%-200% 95% 200%-250% 250% 250%Foot print ration/drive 100% 120% 200% 100% 350% 150%-200% 300%-500%
Offer ATV <75kWATV >75kW
<75kW option ATV optionATV21
fan/pump only Square D USSinewave AccuSine
Altivar AFE
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Where to install the solutions?
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Solutions comparison
●Cost comparison between harmonic mitigation solutions at drive level
Harmonic Mitigation - Cost / Performance Comparison
300
5
Cost/VSD price
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0
50
100
150
200
250
6 Pulse Drive C-Less DC chokesAC chokes
Passive Filters Multi-Pulse12p, 18p
Active Filters
THDI %
60-130 30-35
35-48
5-16
5-105
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Agenda
●Why is there harmonic in the electrical network?
●General waveform signature (IEC 61000-3-6)
●Typical harmonic mitigation solutions
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●Typical harmonic mitigation solutions
●Solutions comparison
●What’s next?
●Conclusion
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What’s next?1st Step – Measure
●Select a good PQ tools and software●Portable power quality loggers●Power Quality Monitoring System
& Power Quality Meter
3rd Step – Implement
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2nd Step – Analyze● Identify & Categorize the PQ
event according to standard (e.g. IEEE Std 1159-1995)
●Know the waveform signature
● Identify the severity of the event (Magnitude and duration)
3rd Step – Implement●Understand the effect of the
events●Propose solutions to apply
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Agenda
●Why is there harmonic in the electrical network?
●General waveform signature (IEC 61000-3-6)
●Typical harmonic mitigation solutions
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●Typical harmonic mitigation solutions
●Solutions comparison
●What’s next?
●Conclusion
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What we were discussing
●Solve the harmonic issue, if possible, starting from the root of the problem.
●A cost effective solution requires the knowledge of the
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●A cost effective solution requires the knowledge of the installation and it is often a combination of several solutions.
●Harmonic mitigation solutions are available in market to fulfill your needs.
3 main messages3 main
messages
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Ch‘ng Eng Yong+6012 – 2750 876
You‘ve got questions?Contact
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TT hank You
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for your attentionTT hank You