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Fluke 6100A Electrical Power Standard Lawrence Rainbird,
The Nordic Calibration Tour

Norman Willgress & Ian Hinchcliffe
Calibration of Power
Measuring Instruments in a
Changing Power Industry
Lawrence Rainbird Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Power
Apparent power = V * I
Power factor (pf) = Cos Active or useful power = V * I * Cos I V Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Power
Reactive power is bi-directional
From energy stored in inductance & capacitance
Power factor (pf) = Cos
= W / VA
Active or Useful Power (W)
Apparent Power (VA)
Reactive or
Magnetising
Power (VAR)
Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Non-sinusoidal power
Cos
now meaningless
Active or Useful Power (W)
I V
? Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Active or Useful Power (W)
Apparent Power (VA) Non-sinusoidal power
Reactive power?
8 Current definitions/calculation methods Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Flicker Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Flicker
Quantifies annoyance effect
Two variables
Depth of modulation
Frequency of modulation
Flicker curves link points of equal annoyance
factor
Currently defined for
230 volt systems
Incandescent bulb
110 volt standard currently being defined Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Flicker
IEC 61000-4-30 Flicker Curv es
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
3.50%
4.00%
4.50%
5.00%
0
5
10
15
20
25
Frequency of Modulation
D
e
pt
h of
M
odul
a
t
i
on
PST=1 Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Flicker
IEC 61000-4-30 Flicker Curv es
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
3.50%
4.00%
4.50%
5.00%
0
5
10
15
20
25
Frequency of Modulation
D
e
pt
h of
M
odul
at
i
o
n
PST=1
PST=2 Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
FlickerMeter Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Fluctuating harmonics
Individual amplitude modulated harmonics
E.G.
Fundamental, 3
rd
, 5
th
, 7
th
, 9
th
all present at constant
amplitude
2
nd
amplitude modulated at 20Hz, 5% modulation depth
Caused by
Variable Loads
* Washing machines, Switched mode power supplies Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Interharmonics
Non integer harmonic
For 50Hz Systems
100Hz, 150Hz, 200Hz etc are
harmonics
51Hz, 93Hz, 211Hz etc are
interharmonics
For 60Hz Systems
120Hz, 180Hz, 240Hz etc are
harmonics
61Hz, 93Hz, 211Hz etc are
interharmonics
Caused by
Variable speed drives, induction motors, static frequency
converters, cycloconverters Switched mode power supplies
and arcing devices.
Power line carrier signals are effectively interharmonics Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Why measure
Problem: appear as amplitude modulation on
voltage supply
Interharmonics
* e.g. 50 Hz beats with 51Hz to cause 1Hz beat frequency
Fluctuating harmonics
* Similar effect to flicker
Important to know real cause when analysing power system
Limits/standards in place to control
Measurement required Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Why measure
Problem: Cause errors in harmonic
measurements
Phase change of harmonic vs sample clock
Different, non integer number of samples per cycle for Fast
Fourrier Transform (FFT)
Signal different for each pass of FFT Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Deregulation and distributed
generation
Generation
Company
Distribution
Company
Customer
Fuel Source: Coal, Natural Gas, Nuclear, Hydro etc
IPP Generation
Local Utility
Generation
Competing
Utility
Generation
(Outside Service
Territory)
Bulk
Transmission
Local
Distribution
Sytem Control
and Reliability
Large C/I
Customers
Small C/I
Customers
Residential
Customers
Self Generation
Private
Lines
Surplus
Power
Purchased
Surplus Power Purchased
Intersystem
Exchange
Power
Waste
Heat
Diagram courtesy of NIST Planning Report
Changing measurement needs in a deregulated electricity
industry Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Words from NIST
...that new standards are needed for nearly every
aspect of the industry (control, pricing, access,
security, distributed generation, brokering, etc.) as
multiple players become involved in the production,
distribution, and selling of power; (2) that there is a
significant risk that emerging international standards
will not reflect the needs or situation of the U.S.
electric power industry; (3) that additional low-
uncertainty measurements are needed to ensure the
accurate sale of power; and (4) that the electric power
industry may become, in the near future, the largest e-
commerce industry in the world. Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
More from NIST
.number and complexity of transactions involved in
those processes are expected to skyrocket. Such a
highly distributed generation network requires advanced
measurements of system parameters that efficiently
send the data to control functions to ensure system
reliability and security. So, while virtually every home
and business has a meter that measures electricity
consumption, that information alone and in its present
usage will not be enough to do the job in the future.
The growing number of companies in the market also will
increase the need for precise information about energy
transactions. More precise measurements of standard
billing parameters will be needed.. Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Calibration issues in power
industry
Accuracy
Environment has changed
New measurements
New standards Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Calibration issues in power
industry
Accuracy
Many more transactions taking place
* More measurements taking place
* More people measuring
* Potential for inconsistency and error
* Errors compound in complex network
Existing calibration solutions susceptible to load
changes
* Different results on different instruments
Existing calibration solutions susceptible to supply
distortion and variation Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Existing calibration philosophy
Reference measurement
Use mains supply, or external source
Compare UUT measurement with reference
measurement
Series and/or parallel connection
Substitution
Source
UUT
Reference
UUT
Reference
Source
Source
UUT
Reference Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Parallel connections
V
UUT
= V
REF
V
REF

V
UUT
V
SOURCE
V
UUT1
V
UUT2
Source
UUT
Reference
Source
Z
source
Z
UUT
Z
REF
Reference
UUT
Z
connect Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Series connections
I
UUT
= I
REF
I
REF

= I
UUT
I
SOURCE
I
UUT1
I
UUT2
Source
UUT
Reference
Source
UUT
Reference
Z
Source
Z
UUT
Z
REF
Z
connect Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Substitution
V
REF

V
UUT1
V
UUT2
I
REF

I
UUT1
I
UUT2
V
REF

= V
UUT1
I
REF

=I
UUT1
Source
UUT
Reference
Source
UUT
Reference
Z
Source
Z
REF
Z
UUT
Z
Connect Lawrence Rainbird,
The Nordic Calibration Tour


Norman Willgress & Ian Hinchcliffe
Recognized problem
problems that exist with the standard phantom
loading method. Because many transformers were needed to
generate matching currents and the required voltages; test
circuits were sensitive to the different burdens presented
them by differ