Post on 02-Oct-2014
Originally presented at EPRI PQA/ADA Conference 2007 – Long Beach, CA
Monitoring Power Quality Beyond EN 50160 and IEC 61000-4-30
Scott SchindlbeckElspec North America23 April 2008Room s401d – 1:00pm
IEEE Transmission & Distribution Conference
Monitoring Electric Power Quality
Chicago, IL
www.elspecna.com
2 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
Objectives for Power Quality Monitoring• Power Quality Statistics• Power Quality Contracts• Power Quality Troubleshooting • Resolving Disputes• Verifying Compliance With Standards
3 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Can Power Quality Really Be Measured?
• Power quality has many meanings depending on what the power is used for
• Measuring PQ is all about deviations from normal state• USERS are interested in any deviation that is large
enough to cause a problem• SUPPLIERS are interested in ensuring that deviations are
maintained below a level that might cause problems
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
4 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Quality Measurement Considerations
• PQ events are multi dimensional dips,voltage,current,time,harmonics,flicker,frequency
• PQ effects have thresholds ( they become problematic above a certain level)
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
5 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Power Quality Parameters
• Supply voltage unbalance• Voltage and current harmonics• Interharmonics• Rapid voltage changes• Power frequency• Magnitude of supply voltage• Flicker• Supply voltage dips and swells• Voltage interruptions• Transient voltages
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
6 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Existing Standards• IEC 61000-4-30
– Measurement methods– Measurement formulas– Accuracy levels– Aggregation period definition
• EN 50160– levels for power quality parameters– time-based percentage
(e.g., limiting voltage flicker to 95% of the time per week)
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
7 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Supply Standard EN 50160
• Governs supply voltage parameters• “95%”• Excludes fault conditions, adverse weather • Important standard but not a guarantee• Written from suppliers point of view
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
8 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Measurement Standard IEC 61000-4-30
• Defines the method of measurement and interpretation of results for power quality parameters in single and three phase 50/60 Hz power systems
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
9 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
• Any instrument conforming to the IEC61000-4-30 Class A standard regardless of manufacturer will read the same when subjected to the same inputs( V,I)
• Creates a level playing field• With today's technology we can measure beyond this
standard providing power quality professionals the information they need to solve real issues
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
10 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
11 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
Current Trends in Power Quality Standards• Several countries are modifying Standards to improve network
power quality. Examples:– Norway (Norwegian Water Resources and Energy Directorate):
• Reduce averaging periods from 10 minutes to 1 minute • Force maximum 100% levels of compliance,
(compared to 95% in EN 50160).– Hungarian Regulatory Agency:
• Force averaging period every 3 seconds
12 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
The impact of existing standards on Power Quality Analysis and Solutions
• Time aggregation hides power quality issues• Parameter values are limited and time-restricted• Power quality variables are bound to only 3 voltages• Source identification and propagation analysis becomes
extremely difficult (or near impossible) due to limited information available from power anomalies
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
13 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
Requirements for Optimizing Power Quality Analysis• Data compression technology• Continuous measurement of available information all the time in1024 sample/cycle
• 2 parallel computation engines: IEC 61000-4-30 Class A andcycle-by-cycle, up to the 511th harmony
• Full scale readings 6000V / 75A at high accuracy• Real time flickering – 2, 10 and 60 second periods• Periodic storage of 4 quadrant energy (active and reactive) fortotal 16 parameters
• Detailed Inter- and Sub-harmonics
14 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
EN 50160 Compliance• Main service of an industrial customer• Unexplained production interruptions and equipment failures • According to EN50160 everything is OK although the site is
experiencing significant damage
ElectricalElectricalUtilityUtility
industrialindustrialConsumerConsumer
22kV
Compliance with EN 50160 at Industrial Customer's Main Service
15 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Not Recording All Parameters: Hidden Line-to-Ground Event• EN50160 limits measurements on Delta connections to Line-to-Line voltages• The following event causes accumulative damage to MV Delta connected• Source: Short circuit between the blue phase and the ground• Result: No Record of a potentially damaging Line-to-Ground event
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
05
10152025
05
10152025
3 Cycles / Div, Total 60 Cycles
L-L
Vol
tage
s [k
V]L-
N V
olta
ges
[kV]
16 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Not Recording All Parameters: Event Analysis• Conclusion from 16 cycles: Line-to-Line Voltage Sag• Insufficient information to identify the source(s)
21
18
15
12
9
24
12
0
-12
-24
24
12
0
-12
-24
24
12
0
-12
-24
29-04-2007 07:33:49.974
Elspec PQSCADA Investigator
29-04-2007 07:33:50.278
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Volts
,L-N
[kV]
Volts
,L-N
[kV]
21
18
15
12
9
24
12
0
-12
-24
24
12
0
-12
-24
24
12
0
-12
-24
29-04-2007 07:33:49.974
Elspec PQSCADA Investigator
29-04-2007 07:33:50.278
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Volts
,L-N
[kV]
Volts
,L-N
[kV]
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
17 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Not Recording All Parameters: Sequence of Events (Zoom-Out)• 1 second of information reveals two sequential events
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Volts
,L-N
[kV]
Volts
,L-N
[kV]
21
18
15
12
9
24
12
0
-12
-24
2412
0
-12
-24
24
12
0
-12
-24
29-04-2007 07:33:49.777 29-04-2007 07:33:50.771
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Volts
,L-N
[kV]
Volts
,L-N
[kV]
21
18
15
12
9
24
12
0
-12
-24
2412
0
-12
-24
24
12
0
-12
-24
29-04-2007 07:33:49.777 29-04-2007 07:33:50.771
Elspec PQSCADA Investigator
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
18 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Not Recording All Parameters: Sequence of Events (L-N Added)• Adding Line-to-Neutral voltages reveals the cause
22
20
18
16
14
12
10
222018161412
10
24
8642
0
29-04-2007 07:33:49.777 29-04-2007 07:33:50.771
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
22
20
18
16
14
12
10
222018161412
10
24
8642
0
29-04-2007 07:33:49.777 29-04-2007 07:33:50.771
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
19 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Not Recording All Parameters: Sequence of Events (Aftershock)• Aftershock event caused by simultaneous re-connection of many
loads after the event22
20
1816
14
12
10
2421181512
9630
28
24
20
16
12
8
4
29-04-2007 07:33:49.777 29-04-2007 07:33:50.771
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Volts
,L-N
[kV]
22
20
1816
14
12
10
2421181512
9630
28
24
20
16
12
8
4
29-04-2007 07:33:49.777 29-04-2007 07:33:50.771
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Volts
,L-N
[kV]
Cur
rent
[A] Monitoring the
Current adds information
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
20 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
High Sampling Rate
-100%
Vol
tage
100% Event at 64 samples per cycle – a Voltage Sag?
Same event at 1,024 samples per cycle –Transients!
Vol
tage
Vol
tage
--100%100%
100%100%
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
21 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Averaging vs. Rapid Parameter Monitoring• Standards recommend averaging periods for parameters• What averaging achieves:
– Fewer resources required, such as less storage space and bandwidth
– More stable readings– Similar information on every analyzer
• What averaging causes:– A large amount of vital power quality information remains hidden– No ability to understand the network and the propagation of events
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
22 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Averaging vs. Rapid Parameter Monitoring• Source: SINTEF Energy Research, Norway
Different Results:•10 minute averaging = Voltage is below 207V 3.5% of the time(nominal 230V minus 10%)
•1 minute averaging = Voltage is below 207V 28% of the time.
•Cycle-by-cycle RMS Voltage Monitoring is essentialin order to understand the cause and provide a solution
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
23 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Continuous Logging - 16 Cycles• Voltage drop at a large industrial area.• Rule of thumb: Voltage drop plus current rise => downstream event
Cur
rent
s [A
]Fr
eq. [
Hz]
2220181614
14
12
10
8
26130
-13-26
20100
-10-20
5251504948
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Cur
rent
s [A
]C
urre
nts
[A]
Freq
. [H
z]
2220181614
14
12
10
8
26130
-13-26
20100
-10-20
5251504948
Elspec PQSCADA Investigator
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Cur
rent
s [A
]
16 waveforms sampling16 waveforms sampling
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
24 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Continuous Logging - ~300 Continuous Cycles (Zoom-Out)• The change in frequency points to an external source
2220181614
14
12
10
8
26130
-13-26
20100
-10-20
5251504948
03-01-2007 17:36:17.750
Elspec PQSCADA Investigator
03-01-2007 17:36:23.893
Cur
rent
s [A
]Fr
eq. [
Hz]
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Cur
rent
s [A
]
2220181614
14
12
10
8
26130
-13-26
20100
-10-20
5251504948
03-01-2007 17:36:17.750
Elspec PQSCADA Investigator
03-01-2007 17:36:23.893
Cur
rent
s [A
]Fr
eq. [
Hz]
Volts
,L-N
[kV]
Volts
, L-L
[kV]
Cur
rent
s [A
]
7 Seconds7 Seconds
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
25 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Continuous Logging – 45,000 Continuous Cycles (2nd Zoom-Out)• The current changes before the event again points to a downstream problem
22
20
18
16
14
21
18
15
12
9
50.28
50.22
50.16
50.1
50.04
49.98
31:43.505
Elspec PQSCADA Investigator
45:08.867
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
22
20
18
16
14
21
18
15
12
9
50.28
50.22
50.16
50.1
50.04
49.98
31:43.505
Elspec PQSCADA Investigator
45:08.867
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
15 minutes15 minutes
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
26 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Continuous Logging – 250,000 Continuous Cycles (3rd Zoom-Out)• Now we see that the current rises are typical to this site
22
20
18
16
14
21
18
15
12
9
50.3
50.2
50.1
50
49.9
16:58:33.273
Elspec PQSCADA Investigator
18:16:22.235
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
22
20
18
16
14
21
18
15
12
9
50.3
50.2
50.1
50
49.9
16:58:33.273
Elspec PQSCADA Investigator
18:16:22.235
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
More then 1 hourMore then 1 hour
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
27 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Large Scale Event• These sites are located 106km (66miles)
from each other and 62km/54kmfrom the original one
• Voltage & Frequency look exactly the same
• Current drops during the event
106km (66miles)106km (66miles)
23.122
20.9
19.8
18.7
50.3
50.2
50.1
50
49.9
24.2
17.6
16.5
150
140
130
120
110
160
100
Elspec PQSCADA Investigator
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
03-01-2007 17:08:42 03-01-2007 18:24:21
23.122
20.9
19.8
18.7
50.3
50.2
50.1
50
49.9
24.2
17.6
16.5
150
140
130
120
110
160
100
Elspec PQSCADA Investigator
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
03-01-2007 17:08:42 03-01-2007 18:24:21
172168164160156
50.3
50.2
50.1
50
49.9
176
152148144140136
39383736
40
353433
50.25
50.15
50.05
49.95
49.85
03-01-2007 17:08:42
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
03-01-2007 18:24:21
Elspec PQSCADA Investigator
172168164160156
50.3
50.2
50.1
50
49.9
176
152148144140136
39383736
40
353433
50.25
50.15
50.05
49.95
49.85
03-01-2007 17:08:42
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
03-01-2007 18:24:21
Elspec PQSCADA Investigator2233
11
22
33
22
20
18
16
14
21
18
15
12
9
50.3
50.2
50.1
50
49.9
16:58:33.273
Elspec PQSCADA Investigator
18:16:22.235
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
22
20
18
16
14
21
18
15
12
9
50.3
50.2
50.1
50
49.9
16:58:33.273
Elspec PQSCADA Investigator
18:16:22.235
Volts
, L-L
[kV]
Freq
. [H
z]C
urre
nts
[A]
11
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
28 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Rapid Parameter Monitoring – RMS in a Welding factory (Germany)• IEC 61000-4-30 instructs: 10/12 Cycle averaging
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94300
310
320
330
340
350
360
370
380
390
400
Sliding Window AverageSliding Window Average
Fixed AverFixed Aver
Cycle-by Cycle
5 different voltage drops
IEC 61000-4-30one voltage drop
Cycle CurrentCycle Voltage
Sliding Window Averageone voltage drop
Current [A] Voltage [V]
Cycle
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
29 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Multipoint Analysis – Multiple Sources• Two different events sources may be wrongly identified as same type• Solving at one transformer will not prevent the event(s) from reoccurring and is likely the wrong analysis
80%
90%
100%
Voltage
First EventFirst EventFirst EventFirst Event Second EventSecond Event
Second EventSecond Event
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
30 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Multipoint Analysis - Time Delay and propagation Analysis• Time synchronization allows time delay analysis
0.1 Sec/Div80%
90%
100%
Voltage
First Event
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
31 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Knowledge Availability
Knowledge
Certainty
Controllers
Power meters
Educated guess
0%
100%
When What Where From Why What to do
Source of Information Educated guess
“Today at 09:00”“From Customer X”
“Motor Startup”“Synch. Startups”
“20% Sag”
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
32 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Ideal Knowledge Availability
Knowledge
Certainty
Controllers
Power meters
Educated guess
0%
100%
When What Where From Why What to do
Source of Information Educated guess
“Today at 09:00”“From Customer X”
“Motor Startup”“Synch. Startups”
“20% Sag”
Continuous measurement of available information
all the time in 1024 sample/cycleusing data compression technology
Source of Information:
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30
33 Copyright © 2007 ELSPEC Engineering, Ltd.. All rights reserved.
Thank YouThank You
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www.elspec.com
Monitoring Power Quality BeyondEN 50160 and IEC 61000-4-30