Overview & Applications
Power Meters
Ben Kemink
Agenda
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Watt is power?
Why do we measure power?
Overview of power meters
Applications and markets
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Watt is Power?
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Watt is power?
Apparent power
(a calculated value)
Apparent power is the total electrical energy available from the
connection point, to do work.
Ps = Papparent = P available
Formula:
Ps = Urms x Irms [VA]
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Watt is power?
Average power, Pavg
(a calculated value)
Also called “True power”, “Active Power”, “Effective Power” or
“Converted Electrical Power”
The Average Power is the calculated average of the instantaneous
transmitted electrical energy.
This is the part we have to pay for and the accumulated value over
time can be read out from the Kilowatt hour meter (Kwh-meter).
Formula:
Pavg = Urms x Irms x Cos φ [W]
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Watt is power?
Cos φ
(a calculated value)
Cos φ, is an indication for the efficiency of energy conversion from
electrical energy into any other kind of energy (Heat, Motion, etc.)
Φ, is the phase difference between voltage and current.
The smaller the phase angle (φ = ideal 0), the better Cos φ = 1, the
higher the power conversion efficiency.
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Watt is power?
Reactive power
(a calculated value)
Reactive power is that part of the energy made available at the
destination, not used (converted) by the end users application.
This energy is continuously transported back and forward through the
power cables.
Due to the resistance of these transportation cables some of this
reactive power is lost (converted into heat).
This is at the cost of the generator power station.
Formula :
Pq = Urms x Irms x sin φ [var]
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Watt is power?
Apparent Power
Available
Average Power
Used
Reactive Power
Not Used
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Watt is power?
The “Power Triangle”
Apparent power
S = Ps = U x I [VA]
Reactive power
Q = Pq = U x I x sin φ [var]
φ
Active power
P = Pavg = U x I x cos φ [W]
Ps = Pq + Pavg
These are all calculated average values!
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Why do we measure power?
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Why do we measure power?
Electrical Power Plants are designed and built to
generate electrical power. After completion this needs
to be verified for an acceptance test.
If energy is traded between an Electrical Power Plant and Industrial
Company, the amount of energy needs to be measured correctly at
both ends. A power standard and reference is required.
Power supplies of daily used instruments are designed
and built as small as possible and as light-weight as
possible. Still they need to work correctly even under
the most severe circumstances. This needs to be
verified.
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Why do we measure power?
In the past mechanical
power was driven by
horses, wind, steam and
explosion engines.
Today the majority of
mechanical power is
generated by an electric
motor.
Steam engine
The electrical specifications of this motor must be measured, in order to
verify if its electrical power is sufficient to do the required mechanical job.
Every household has a so called kWh-meter or energy
meter to measure the used electrical power over time.
Every kWh has to be paid for, so you better measure
it correctly!
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Why do we measure power?
Under pressure of environmental control legislation,
manufacturers of electrical equipment are forced to
minimize power consumption. If two washing
machines perform an evenly good job in washing,
the one using less energy is favorite. It will rank
higher in the list of preferred products made by the
Consumer Test Associations.
Power transformers delivered to Power Stations are locally verified
before installation.
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Energy Saving : Electric Power
Power :
Power equipment
(motor, pump, fan,
machine tool)
Electromagnet
(solenoid)
Heat : Heating (heater,
furnace)
Light : Illumination
Others: General purpose
electrical machinery,
Electric and electronic
equipment, etc.
Effective power
+
Power loss
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Overview of Power Meters
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History models
Most important power meters in the past were:
 1990-1996 2531 digital power meter
 1990-1997 2533 digital display power meter
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1995-2000 WT110 / WT130 digital power meters
2000-2002 WT200 digital power meter (successor of WT110)
1996-2001 WT1000 digital power meter (successor of 2533)
1997-2002 WT2000 digital power meter (successor of 2531)
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CW100 & CW200 hand-held power meter series
CW100 & CW200 series
 Light weight, small sized battery powered electric energy and power
meter for field applications
 Wiring check
 High speed field data logging. Up to 1 per second
 Efficiency measuring two 3-phase loads at the same time
Bandwidth: 45 – 65 Hz
Sample Speed: 8.3 kS/s
ADC: 16 bits
Power accuracy: 0.6 %
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WT210 / WT230 digital power meters
WT210 (1-phase) & WT230 (2-3 phase) series
 One compact instrument to measure voltage, current, phase angle, power
factor, harmonics etc.
 The most used power meter in production facilities
 Extremely good price/performance ratio
 Down to a 5mA range (WT210) to measure standby/sleep mode power
with 25µA resolution.
 Go-NoGo test output for quality control
Bandwidth: 0.5 Hz-100 kHz
Sample speed: 51 kS/s
ADC: 16 bits
Power accuracy: 0.1%
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WT1600S digital power meter
WT1600S
 The WT1600S offers electrical pump and motor tester a free selection of
input elements and a wide choice of measurement ranges for a higher
accuracy.
 Highest accuracy for electrical energy measurements by offering a continue
sample speed of 200kS/s.
 Mechanical torque and rotation speed input for efficiency measurements.
Bandwidth: 0.5 Hz-300 kHz
Sample speed: 200 kS/s
ADC: 16 bits
Power accuracy: 0.1 %
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WT1600 digital power meter
WT1600
 With 6 elements the WT1600 allows efficiency measurements of 3-phase4 wire input/output systems.
 Standard Master-Slave function allows synchronize operation of four
WT1600 power meters or 24 power elements.
 Wide input frequency range DC, 0.5-1MHz.
 Trend display
 Up to the 100th higher harmonic
Bandwidth: 0.5 Hz-1 MHz
Sample speed: 200 kS/s
ADC: 16 bits
Power accuracy: 0.1 %
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WT3000 digital power analyzer
WT3000
 Worlds most stable and most accurate power analyzer.
 The WT3000 supports the 50/60 Hz (10/12 cycles) of inter-harmonic
measurement required by IEC61000-4-7 edition 2. Is able to measure
on IEC compliant harmonic measurements and Voltage Fluctuation &
Flicker measurements.
 4 input modules.
 8.4 inch LCD screen.
 USB & Ethernet interface.
Bandwidth: 0.1 Hz-1 MHz
Sample speed: 200 kS/s
ADC: 16 bits
Power accuracy: 0.02 %
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PZ4000 power analyzer
PZ4000
By combining a high precision power measurement and long memory
oscilloscope technologies, Yokogawa created the instrument
suitable for measuring and analyzing the power in varying loads and
in the faster transients, like robotics and soft starters.
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DSO type of triggering and cursor measurements.
Harmonic analysis up to the 500th order.
4 input elements (modular).
Torque and speed inputs.
Bandwidth: 2 MHz
Sample speed: 5 MS/s
ADC: 12 bits
Power accuracy: 0.1 %
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Markets
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Markets
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Lighting
Pumps
Inverters
Transformers
Hybrid
Fuel Cell
Wind energy
Solar
UPS
Power supplies
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Markets
 Lighting
Characterize the lamp (R&D): Excellent PZ4000 application
Production: WT3000 / WT1600(S)
Energy measurements (consumption): WT210 / WT230
Customers:
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Markets
 Pumps
Characterize the pump (start-up behavior):
PZ4000 application
Testing: WT3000 / WT1600 / WT230
Customers:
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Markets
 Inverters
Research &Developments : PZ4000
Testing
: WT3000/WT1600
Production
: WT230
Customers:
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Markets
 Transformers
Excellent WT3000 application!
Customers:
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Markets
 Hybrid Cars
Perfect WT1600 application!
Customers: Most car manufactures!
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Markets
 Fuel cell
A WT1600FC application
Customers:
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Markets
 Wind energy
Research & Development : WT3000
PZ4000
Testing
: WT1600
Customers:
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Markets
 Solar
Research & Development : PZ4000
Testing
: WT1600 / WT230
Customers:
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Markets
 Uninterruptible Power Supplies (UPS)
Research & Development : PZ4000
Testing & production
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: WT1600
Do you have a question ?
Thank You
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