Transcript Slide 1

Organizing Survey Information about
Harmonic Distortion Levels
IEC SC77A, WG1
Montreal
October 14, 2004
Mark McGranaghan
EPRI PEAC Corporation
[email protected]
865-218-8029
Scope
• Collect, organize, and present the results of
harmonic measurements from around the
world.
• Analyze results for development of impact
factors for incorporation into the network
impact factor model.
• Evaluate the measurement results with
respect to theoretical models being used to
develop harmonic limits.
Procedure
• Collect data from utility measurement
programs
• Previous benchmarking efforts with
additional data collection
– CIGRE C4.07 benchmarking effort
– DPQ
– CEA Technologies
• Internal utility monitoring projects
• Include important parameters describing the
systems measured
List of Parameters to be Documented
•
•
•
•
•
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•
•
Voltage
Location of Measurements
Capacity at Substation
Load types
Characteristics 1 - UG/OH
Characteristics 2 - Capacitors
Characteristics 3 - load density
Known harmonic sources
List of Prospective Contributors
•
United States
–
–
–
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–
–
–
•
Canada
–
–
–
•
•
John Sinclair coordination
EA Technologies
Scottish Power
PowerGen (East Midlands Electricity)
Ireland – ESB Networks
Sweden
–
–
•
•
•
CEA Technologies project
Hydro Quebec
BC Hydro
South Africa – ESKOM
UK
–
–
–
–
•
•
EPRI DPQ project results
United Illuminating
San Diego Gas & Electric
TVA
Con Edison
PSE&G
First Energy
Lincoln Electric
Southern Company
Progress Energy/Carolina Power & Light
Entergy
Math Bollen
Vattenfall
Belgium
Netherlands
Romania
•
•
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•
France - EdF
Norway - SINTEF
Romania - Stefan Gheorghe
Germany - Rolf Gretsch
•
•
•
•
•
Czech Republic
Poland
Hungary
Austria
Italy
•
Spain
–
–
–
–
•
Hamburg measurements
CESI
Iberdrola
Endesa
Brazil
–
–
ENERQ/Sao Paulo
CEPEL
•
•
Argentina
Japan - Saitu Hajime
•
•
•
•
•
Korea – KEPCO
Singapore – PowerGrid
Malaysia – TNB
Hong Kong – CLP Power
Macau
–
Japanese PQ Survey
DPQ Project
• 24 utilities
• 277 primary
distribution feeder
sites
• 27 months
DPQ Project –
Feeder monitoring locations
Voltage Harmonic Distortion:
Distribution of All Sites
Average Voltage THD at Each Monitoring Site
100%
Frequency of Sites
16%
Mean (SATHD):
1.57%
Standard Deviation:
0.0714%
95% Confidence Interval:
1.43% to 1.71%
14%
12%
80%
60%
10%
8%
40%
6%
4%
20%
2%
6.6
6.0
5.4
4.8
4.2
3.6
3.0
2.4
1.8
1.2
0.6
0%
0.0
0%
Cumulative Frequency
18%
VTHD (%)
Source: EPRI TR-106294-V1
Histogram of Average Value for Voltage THD at 277 Monitoring Sites from 6/1/93 to 3/1/95 (Treated by Sampling Weights)
Voltage Harmonic Distortion:
Distribution of All Sites
CP95 Voltage THD at Each Monitoring Site
14%
100%
Frequency of Sites
80%
Mean:
2.18%
CP95 (STHD95):
4.03%
Standard Deviation: 0.101%
95% Confidence Interval:
1.99% to 2.38%
10%
8%
70%
60%
50%
6%
40%
4%
30%
20%
2%
Cumulative Frequency
90%
12%
10%
6.6
6.0
5.4
4.8
4.2
3.6
3.0
2.4
1.8
1.2
0.6
0%
0.0
0%
VTHD (%)
Source: EPRI TR-106294-V1
Histogram of CP95 Value for Voltage THD at 277 Monitoring Sites from 6/1/93 to 3/1/95 (Treated by Sampling Weights)
DPQ – Individual Harmonic
Components (site average values)
% of Fundamental
2.5
CP05
2
Mean
1.5
CP95
1
0.5
0
THD
2
3
4
5
6
7
8
9
10
11
Voltage THD and Individual Harmonics
12
13
DPQ - Seasonal Effects
SATHD Index Values Computed by Month
2.0%
SATHD
1.8%
1.6%
1.4%
1995
1994
1993
1.2%
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
1.0%
Month of Project
SATHD Value by Month, From 6/1/93 to 9/1/95, Unweighted, All Sites
DPQ - Conclusions
• System Average Total Harmonic
Distortion (SATHD) was 1.57%
• System Total Harmonic Distortion CP95
(STHD95) value was 4.04%
• Seasonal variations are important
– Load dependence?
LFEIC Survey of Harmonic Voltage
Distortion Levels in Europe –
Discussion of Results and Implications
LFEIC Survey of Harmonic Voltage
Distortion Levels in Europe – Phase 1
• Year 2000
• 74 residences – harmonic voltage distortion over
one week period at each residence
• 8 countries
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–
–
Austria
France
England
Ireland
Italy
Germany
Netherlands
Spain
Types of Loads
Questionnaire
Country Representative only:
ID-Nr:
Country:
Name:
Address:
Country/Province:
Phone:
Fax:
Email:
Monitoring month:
Number of households in house
Location of Home
Number of persons in household:
Single-Family
In the City
2 or 3 (Multi-Family)
Urban
4 to 8 (Multi-Family)
more than 8 (Multi-Family)
Total Living Space (Square Meters):
Heated Space (Square Meters):
Air-Conditioned (Square Meters):
Rural
Energy Types
Application
Electricity
Gas
Oil
Energy Carrier
Coal
Wood
District Heating
Cooking
Warm Water
Heating
Air-Cond
Special events during measurement. (Examples: Interruption of power, thunderstorms, …)
Date
Time
Event
Others
Harmonic Profile
Example of results for all the sites
in one country
Results by Country
The Results –
Overall Aggregate Harmonic Profile
Phase 2 Survey – Sept 2002 - July 2003
• Survey of same sites from Phase 1
• Evaluate consistency of harmonic
levels
• Possible seasonal variations?
Comparison of Phase 1 and
Phase 2 Results
• Comparison for 66 sites
in common between the
two sets of
measurements
• Changes in harmonic
levels were basically
insignificant
Observations
• Harmonic voltage distortion levels at the residences surveyed
are well below the compatibility levels specified in IEC 61000-32 and EN 50160 at the CP95 probability level.
• Harmonic voltage distortion levels tend to be highest in the
evening and on weekends for the residential sites surveyed.
• The harmonic voltage distortion at the residential locations
surveyed is dominated by the fifth harmonic component, with a
CP95 level of about 3.5%.
• The CP95 THD Level at European residences is very similar to
the CP95 THD Level on US Distribution Feeders
– Europe Residences – 3.8%
– US Distribution Systems – 4.0%
Some other recent European surveys
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•
•
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•
•
EdF – 20 sites (16 random)
Nuon - Netherlands
Czech Republic
Poland
UK
Hamburg LV Measurements
EdF
• Measurements at LV Substations
– 5 LV Networks – Residential
– 4 LV Networks – Industrial
– 7 LV Networks – Commercial
• 4 LV Substations with high harmonic levels
(customer complaints)
• Additional 4 sites at the end of LV networks
• Distributions provided for the 16 LV substations
selected randomly
• Question
– The systems with high 5th harmonic – are any of these
residential systems or only the industrial systems?
EdF - Harmonic Results for 16 LV
Systems
EdF Results - Further Investigation of 5th
Harmonic Levels
EdF Results - Effect of Measuring at the
end of LV Network
• Additional impedance of LV system can cause higher
3rd harmonic voltage levels at the end of the LV
systems
• Not an issue for the MKV system due to Delta-Wye
transformers
Netherlands –
Nuon Measurements from 1996-2001
• Paper 2.77 CIRED 2003
• Measurements
– 75 at LV households
– 126 MV substations (10 kV)
– 67 in HV Grid (50, 110, 150 kV)
Average of the weekly 95% values
Maximum of the weekly 95% values
Nuon – More detailed measurements at
specific location
• LV system with fast growing population (Almere)
• Effect of TV loads is clear (5th harmonic)
• 7th and 11th components due to industry
Typical summer week –
peaks of 5th correspond to TV load
Typical winter week –
Reduced 5th peaks due to central heating
(damping)
Nuon – Additional Results
• 50 MVAR and 100 MVAR
capacitor banks added to
grid (450 MVAR total)
• Recent banks have been
installed as 5th harmonic
filters
Measurements at 150 kV Bus (Almere)
Showing effect of cap banks
Tuned to 5th harmonic
Effect of 100 MVAR cap bank
Not tuned to 5th harmonic
(Measurements at Almere 150 kV Bus)
Effect of 100 MVAR cap bank
Not tuned to 5th harmonic
(Measurments at LV Bus)
Poland – 110 kV Supplies to Cracow (3
Stations) - EPQU 2003 Paper
Typical workday
Statistical results for Wanda 110 kV
Poland – 110 kV Supplies to Cracow (3
Stations) - additional results
Effect of Poland-South Korea Soccer Match
Czech Republic Measurements (Ostrava)
- EPQU 2003 Paper
• 3 years of measurements throughout network
Czech Republic Measurements (Ostrava)
• Neutral conductor
loading
Romania - Monitoring in 6 kV and 20 kV
Systems
• CIGRE/IEEE Conference 2003 – Paper 310
Results Compiled for
CIGRE C4.07/CIRED
• Surveys of harmonic distortion at MV,
HV, EHV
• Evaluation of indices
• Comparison with planning levels
Recommended Voltage Characteristics
Harmonic
Order
(h)
MV
Harmonic Voltage
(%)
HV – EHV
Harmonic Voltage
(%)
3
5
2,5
5
6
3,0
7
5
2,5
11
3,5
1,7
13
3
1,7
17
2
1,2
19
1,5
1,2
23
1,5
0,8
25
1,5
0,8
THD
8
4
Recommended Planning Levels
Odd order non-multiple of 3
Order
Harmonic voltage %
MV
HV-EHV
5
5
2
7
4
11
Odd order multiple of 3
Order
Harmonic voltage %
MV
HV-EHV
3
4
2
2
9
1,2
3
1,5
15
13
2,5
1,5
17
1,6
1
19
1,2
23
Even order
Order
Harmonic voltage %
MV
HV-EHV
2
1,6
1,5
1
4
1*
1*
0,3*
0,3*
6
0,5*
0,5*
21
0,2 *
0,2 *
8
0,4*
0,4*
>21
0,2 *
0,2 *
10
0,4*
0,4*
1
12
0,2 *
0,2 *
1,2
0,7
>12
0,2 *
0,2 *
25
1,2
0,7
>25
0,2 +
0,5
(25/h)*
0,2 +
0,5 (25/h)
NOTE: Total harmonic distortion (THD): 6,5% at MV and 3 % at HV.
Results of Harmonic Surveys at MV
• 2 surveys that complied with criteria
• 178 sites
7
% of Un
6
5
4
3
2
1
49
Harmonic order
Planning levels
UhSh95 - mean (95% site)
THD
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
9
10
8
7
6
5
4
3
2
0
Survey results at MV, cont
H
Measurement results
95%-site for Uh,sh95
Measurement results
max-site for Uh,sh95
Planning
levels
Min
Max
Mean
Min
Max
Mean
3
1,5
2,8
2,15
2
3,7
2,85
4
5
2,56
4,5
3,53
4,2
5
4,6
5
7
1,3
1,5
1,4
1,5
3,4
2,4
4
11
0,5
0,95
0,75
1
3,8
2,4
3
Results of Harmonic Surveys at HV
• 7 surveys
• 284 sites
3,5
% of Un
3
2,5
2
1,5
1
0,5
Harmonic order
Planning levels
UhSh95 - mean (95% site)
49
THD
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
9
10
8
7
6
5
4
3
2
0
Survey results at HV, cont.
Measurement results
95%-site for Uh,sh95
Measurement results
max-site for Uh,sh95
Planning
levels
H
Min
Max
Mean
Min
Max
Mean
3
0,62
1,51
1,13
1
2,51
1,5
2
5
1,0
3
2,13
1
3,2
2,5
2
7
0,4
2,14
1,22
0,4
2,4
1,3
2
11
0,48
1,24
0,64
0,5
1,5
0,78
1,5
Results of Harmonic Surveys at EHV
• 2 surveys
• 217 sites
3,5
% of Un
3
2,5
2
1,5
1
0,5
49
Harmonic order
Planning levels
UhSh95 - mean (95% site)
THD
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
9
10
8
7
6
5
4
3
2
0
Survey results at EHV, cont.
Measurement results
95%-site for Uh,sh95
Measurement results
max-site for Uh,sh95
Min
Max
Mean
Min
Max
Mean
3
0,6
0,71
0,65
0,6
1,4
1
2
5
1,81
2,4
2,1
2,51
3
2,75
2
7
0,66
1
0,83
1
1
1
2
11
0,56
0,6
0,58
0,6
0,71
0,65
1,5
H
Planning
levels
Harmonic Measurements in LV Networks
– Hamburg, Germany
• Measurements in all
seasons of the year
• 1 week measurement
periods
• All types of LV
locations
• Theory that higher
distortion levels may
be due to types of
loads
Hamburg measurements –
3rd and 5th harmonic levels
Voltage u3, 95%-values
3,5
Measurement duration 1 week each, evaluation according to European standard EN 50160
All measurement points situatied in different LV networks in Hamburg
2,5
2
1,5
Voltage u5, 95%-values
1
7
0,5
6
0
0
10
20
30
40
number of mesasurements
50
harm. voltage in % Un
harm. voltage in % Un
3
60
5
4
3
2
Measurement duration 1 week each, evaluation according to European standard EN 50160
All measurement points situatied in different LV networks in Hamburg
1
0
0
10
20
30
40
number of mesasurements
50
60
Korea Measurements
• Measurements in MV System for one
year
High-Voltage
System
154 kV / 22.9 kV
45 MVA
345 kV / 154 kV
500 MVA
MV Feeder
ZTL
22.9 kV / 220, 380V
50, 75, 100 kVA
Y-Y
Y-Y
Power
plant
Low-Voltage
System
Middle-Voltage
System
ZDL
ZDL
ZDL
ZDL
Y-Y
ZTL
ZDL
ZDL
5 ~ 7
Feeder / Tr
200 ~ 300
Tr / Feeder
20 ~ 30
House / Tr
Korea Characteristics
• MV - 22.9kV
• Substation transformer capacity is 45 MVA.
Impedance=12%.
• Distribution line load capacity = 10MVA.
• Distribution System has five to six distribution lines.
• Distribution line lengths - 2 to 5 KM in urban area
and 5 to 20KM in rural area.
• One distribution line supplies 200-300 LV
transformers.
• One LV transformer supplies 20 to 30 Households.
Korea Characteristics, cont.
MV Network (3Φ 4W
22.9kV)
Vbc(22.9kV)
b
c
Vb
Vab(22.9kV)
Va
Vc V (22.9kV)
ac
a
Primary Coil Side
Transformer
LV Network
(3Φ 4W 380V)
Secondary Coil Side
LV Network
(1Φ 2W220V)
Secondary
Circuit
380V
220V
Service Drop
House
220V
Load
380V
Load
Summary results
Reference 1_Total
500
100%
Frequency
Frequency
cumulative probability function%
450
90%
400
80%
350
70%
300
60%
250
50%
200
40%
150
30%
100
20%
50
10%
0
0%
0
0.6
1.2
1.8
2.4
3
3.6
4.2
4.8
5.4
Voltage Distortion[%]
Reference 1_Total
6
Maximum
Mean
Minimum
5
VTHD[%]
• 33 sites (12 substation, 21
distribution line)
• 2 industrial, 13 commercial,
18 residential
4
3
2
1
0
1
8
15
22
29
36
43
50
DAY
57
64
71
78
85
92
Industrial
Reference 1_Industrial area
90
cumulative probability function %
80
90%
70
80%
5
Maximum
60%
50
50%
40
40%
30
30%
Minimum
4
70%
60
Mean
4.5
3.5
VTHD[%]
Frequency
Reference 1_Industrial area
100%
Frequency
3
2.5
2
1.5
20
20%
10
10%
0
0%
1
0.5
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Voltage Distortion[%]
2
2.2
2.4
2.6
2.8
0
1
8
15
22
29
36
43
50
DAY
57
64
71
78
85
92
Commercial
Reference 1_Business area
Reference 1_Business area
300
cumulative probability function %
250
200
80%
4
70%
3.5
60%
150
50%
40%
100
30%
20%
50
10%
0
0%
0
0.2
0.4
0.6
0.8
1
1.2 1.4
1.6
1.8
2
2.2
2.4 2.6
2.8
3
3.2 3.4
Maximum
4.5
90%
VTHD[%]
Frequency
Frequency
5
100%
Minimum
3
2.5
2
1.5
1
0.5
0
1
Voltage Distortion[%]
Mean
8
15
22
29
36
43
50
DAY
57
64
71
78
85
92
Maximum weekly 10 minute values for
individual harmonics
Reference 2_residential area
Reference 2_Business area
35
Frequency
cumulative probability function %
30
100%
80
90%
70
100%
Frequency
cumulative probability function %
90%
80%
25
70%
60%
20
50%
15
40%
70%
Frequency
Frequency
80%
60
50
60%
40
50%
30
40%
30%
10
30%
20
20%
5
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
20%
10%
10
0%
0
10%
0%
2.2
0
0.4
0.8
1.2
3rd Voltage Distortion[%]
Maximum
Mean
cumulative probability function %
3.2
3.6
4
100%
Frequency
90%
35
3.5
cumulative probability function %
90%
60
80%
80%
30
2
1.5
25
60%
20
50%
15
40%
30%
1
10
0.5
5
2
3
4
5
6
7
8
9
10
11
12
13
60%
50%
30
40%
30%
20
20%
10
10%
10%
0%
0
14
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
0
0%
0
2.4
0.4
0.8
1.2
1.6
2
2.4
2.8
3.2
5th Voltage Distortion[%]
5th Voltage Distortion[%]
Week
Reference 2_residential area
80
Reference 2_Business area
60
100%
Frequency
100%
cumulative probability function %
90%
70
90%
50
Frequency
cumulative probability function %
80%
70%
40
60%
30
80%
60
50%
70%
Frequency
1
70%
40
20%
0
0
Frequency
Frequency
2.5
50
70%
3
Frequency
5th Voltage[%]
2.8
70
100%
Frequency
2.4
Reference 2_residential area
40
Minimum
2
3rd Voltage Distortion[%]
Reference 2_Business area
Reference 2_Industrial area
4
1.6
50
60%
40
50%
30
40%
40%
20
30%
10
0
0.2
0.4
0.6
0.8
1
1.2
1.4
7th Voltage Distortion[%]
1.6
1.8
2
2.2
20%
20%
10
10%
0
0%
0
30%
20
10%
0%
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
7th Voltage Distortion[%]
1.8
2
2.2
2.4
“Denki Kyoudou Kenkyu-Kai” Report
(1990)
no reduction
6
5
4
3
THD-V
%
10
network-end
network-end
THD-V
%
10
no reduction
5
4
3
▲25% &
▲50%
1987
1990
2000
▲25% &
▲50%
2010
year
Residential area
(8pm, non-working
day)
Copyright Federation of Electric power companies, 2004 PQIG
1987
1990
2000
2010
year
Industrial area
(2pm, working day)
Guidelines for Harmonics Reduction
2 Different Guidelines
were settled in September, 1994.
Guideline A
GL for General & Household Equipment
(based on IEC 61000-3-2)
Guideline B
GL for Customers Connected to MV/HV Network
Copyright Federation of Electric power companies, 2004 PQIG
Guidelines for Harmonics Reduction
Regulator
(Government)
Manufacturers
Power Suppliers
Customers
Strong Collaboration
(Operation along with Guide Lines)
Realization of Harmonics Reduction
Copyright Federation of Electric power companies, 2004 PQIG
THDv at 6kV MV Systems
(Residential)
6.0
THD-V(%)
5.0
Average+2σ
4.0
3.0
2.0
Average
1.0
0.0
94
95
96
Copyright Federation of Electric power companies, 2004 PQIG
97
98 99
Year
00
01
02
03
THDv at 6kV MV Systems
(Commercial & Industrial)
6.0
THD-V(%)
5.0
4.0
Average+2σ
3.0
2.0
Average
1.0
0.0
94
95
96
Copyright Federation of Electric power companies, 2004 PQIG
97
98 99
Year
00
01
02
03
THDv at 22 - 154kV HV Systems
6.0
THD-V(%)
5.0
4.0
3.0
Average+2σ
2.0
1.0
Average
0.0
94
95
96
Copyright Federation of Electric power companies, 2004 PQIG
97
98 99
Year
00
01
02
03
THDv at 187 - 500kV HV Systems
6.0
THD-V(%)
5.0
4.0
Average+2σ
3.0
2.0
1.0
Average
0.0
94
95
96
Copyright Federation of Electric power companies, 2004 PQIG
97
98 99
Year
00
01
02
03
Win.P.
N.Y.H.
Oct.
Sum.H.
Sum.P.
Spr.H.
Win.P.
N.Y.H.
Oct.
Sum.H.
Sum.P.
Spr.H.
Winter Peak
New Year Holidays
Oct.
Summer Holidays
Summer Peak
Spring Holidays
Win.P.
N.Y.H.
Oct.
Sum.H.
Copyright Federation of Electric power companies, 2004 PQIG
2003
2002
2001
2000
Year
Sum.P.
Season
Average+2σ
Average
5
4
3
2
1
0
THD-V(%)
Seasonal change of THDv at 22 – 154kV
HV Systems
3
1
Win.P.
N.Y.H.
Oct.
Sum.H.
Sum.P.
Spr.H.
Win.P.
N.Y.H.
Oct.
Sum.H.
Sum.P.
Spr.H.
Winter Peak
New Year Holidays
Oct.
Summer Holidays
Summer Peak
Spring Holidays
2000
Win.P.
N.Y.H.
Oct.
Sum.H.
2003
2002
2001
Copyright Federation of Electric power companies, 2004 PQIG
Year
Sum.P.
Season
Average
0
Average+2σ
4
2
THD-V(%)
Seasonal change in THDv at 187 – 500kV
HV Systems
5
Actual harmonic problems (2002)
General
Equipment
Others 1.9%
17.3%
Capacitors
42.3%
Series
Inductors
38.5%
(Note; These are only counted by reports to Power Suppliers.)
Copyright Federation of Electric power companies, 2004 PQIG
Experience with harmonic problems
• Harmonic distortion levels on distribution systems
are usually well within limits.
• However, a small percentage of the time, harmonic
levels can be high enough to cause problems.
• Problems experienced:
– Capacitors failing or fuses blowing
– Customers complaining of problems with electronic
equipment, power factor correction, motors, or transformers
– Telephone interference
– Ground currents causing stray voltages and interference
Parallel resonance – the most important
problem
Distribution Substation Bus
Magnified Harmonic Current
Series resonance at customer bus
Distribution Substation Bus
High
Voltage
Distortion
High
Harmonic
Currents
Customer
Power Factor
Correction
Frequency response characteristics
(example – from end of feeder)
• Combination of substation capacitor bank
and feeder capacitor banks
12
Frequency Scan at Substation
10
Light Load
8
6
Heavy Load
Impedance (ohms)
4
2
0
0
6
12
Harmonic Level
18
24
The load also affects the response of
the overall system
40
Frequency Scan at Mid-Feeder
With linear loads only
30
With non-linear and linear loads
20
Impedance (ohms)
10
0
0
6
12
Harmonic Level
18
24
Example of resonance problem on
supply system
• Resonance on distribution system causing high
voltage distortion.
• Customers complaining about UPS operation.
Trend of Phase A Voltage Total Harmonic Distortion
10%
Samples: 622
Minimum: 0.0045
Average: 0.0361
Maximum: 0.0910
9%
8%
V THD A
7%
6%
5%
4%
3%
2%
1%
0%
5/2/00
5/4/00
5/6/00
5/8/00
5/10/00
5/12/00
5/14/00
5/16/00
5/18/00
Resonance problem
Substation Capacitor Only
3241> 23KV.A( M YSC AN 1A)3241> 23KV.A( M YSC AN 2A)3241> 23KV.A( M YSC AN 2B)
150
3241> 23KV.A( M YSC AN 2C3241>
)
23KV.A( M YSC AN 2D )
Voltage (V)
100
50
0
1
3
5
7
9
11
F r eq uency ( H pu)
13
15
17
19
Filter solution at utility substation
Varying Filter Size
3241> 23KV.A( M YSC AN 1A)
3241> 23KV.A( M YSC AN 4A)
3241> 23KV.A( M YSC AN 5A)
100
80
Voltage (V)
60
40
20
0
1
3
5
7
9
11
F r eq uency ( H pu)
13
15
17
19
Substation harmonic filters
Voltage distortion when filter
installed
Harmonic filters at ESB (Ireland)
substations
Questions to answer
•
•
•
•
•
•
Effect of network characteristics on harmonic
levels
Effect of loading levels on harmonics – both
linear load and nonlinear load
Propagation of harmonics on the MV and LV
systems
Cancellation of harmonics from multiple sources
as a function of the types of sources, frequency
components, etc.
What are the most effective (technical and cost)
methods for controlling harmonics?
Future - harmonic limits based on expected impacts
and overall economics associated with the limits and
impacts
International Collaborative Project –
Distribution System Harmonics
• EPRI PEAC is organizing an international
collaborative project:
– www.distributionharmonics.com
• Objectives
– Characterize levels of harmonics on distribution systems
around the world
– Important concerns for harmonic distortion, including
ground currents, resonance, etc.
– Effect of system design characteristics
– Methods for controlling harmonics (customer limits, filtering,
design considerations)
• Case study library
• Application guide