User Manual
TPS2PWR1
Power Analysis Application
071-1452-01
www.tektronix.com
Copyright © Tektronix, Inc. All rights reserved. Licensed software products
are owned by Tektronix or its suppliers and are protected by United States
copyright laws and international treaty provisions.
Use, duplication, or disclosure by the Government is subject to restrictions as
set forth in subparagraph (c)(1)(ii) of the Rights in Technical Data and
Computer Software clause at DFARS 252.227-7013, or subparagraphs (c)(1)
and (2) of the Commercial Computer Software -- Restricted Rights clause at
FAR 52.227-19, as applicable.
Tektronix products are covered by U.S. and foreign patents, issued and
pending. Information in this publication supercedes that in all previously
published material. Specifications and price change privileges reserved.
Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077
TEKTRONIX, TEK, and TEKPROBE are registered trademarks of
Tektronix, Inc.
WARRANTY
TPS2PWR1 Application
Tektronix warrants that the product listed above will be free from defects in materials and
workmanship for a period of one (1) year from the date of original purchase from an
authorized Tektronix distributor. If any such product proves defective during this warranty
period, Tektronix, at its option, either will repair the defective product without charge for parts
and labor, or will provide a replacement in exchange for the defective product. Batteries are
excluded from this warranty. Parts, modules and replacement products used by Tektronix for
warranty work may be new or reconditioned to like new performance. All replaced parts,
modules and products become the property of Tektronix.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect
before the expiration of the warranty period and make suitable arrangements for the
performance of service. Customer shall be responsible for packaging and shipping the
defective product to the service center designated by Tektronix, shipping charges prepaid and
with a copy of Customer proof of purchase. Tektronix shall pay for the return of the product to
Customer if the shipment is to a location within the country in which the Tektronix service
center is located. Customer shall be responsible for paying all shipping charges, duties, taxes,
and any other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or
improper or inadequate maintenance and care. Tektronix shall not be obligated to furnish
service under this warranty a) to repair damage resulting from attempts by personnel other
than Tektronix representatives to install, repair or service the product; b) to repair damage
resulting from improper use or connection to incompatible equipment; c) to repair any damage
or malfunction caused by the use of non--Tektronix supplies; or d) to service a product that has
been modified or integrated with other products when the effect of such modification or
integration increases the time or difficulty of servicing the product.
WARRANTY (Continued)
TPS2PWR1 Application
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THE PRODUCT IN
LIEU OF ANY OTHER WARRANTIES, EXPRESS OR IMPLIED. TEKTRONIX AND ITS
VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’ RESPONSIBILITY TO REPAIR
OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY
PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX
AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER
TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF
SUCH DAMAGES.
Table of Contents
General Safety Summary iii............................
Contacting Tektronix vii................................
Getting Started
Getting Started 1--1......................................
Basic Operation 1--2.....................................
Ratings 1--2............................................
Start Up 1--4...........................................
Checking Module Installation 1--8..........................
Troubleshooting Module Installation 1--9....................
Reference
Power Analysis 2--1.....................................
Waveform Analysis 2--9..................................
Phase Angles 2--15.......................................
Harmonics 2--21.........................................
Switching Loss 2--29......................................
dY/dt Measurements 2--41.................................
P5120 Specifications 2--43.................................
TPS2PWR1 Power Analysis User Manual
i
General Safety Summary
Review the following safety precautions to avoid injury and prevent
damage to this product or any products connected to it.
To avoid potential hazards, use this product only as specified.
Only qualified personnel should perform service procedures.
To Avoid Fire or Personal Injury
Use Proper Power Cord. Use only the power cord specified for this
product and certified for the country of use.
Connect and Disconnect Properly. Do not connect or disconnect probes
or test leads while they are connected to a voltage source.
Connect and Disconnect Properly. Connect the probe output to the
measurement instrument before connecting the probe to the circuit
under test. Disconnect the probe input and the probe reference lead
from the circuit under test before disconnecting the probe from the
measurement instrument.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all
ratings and markings on the product. Consult the product manual for
further ratings information before making connections to the product.
Use Proper Probe. To avoid shock hazard, use a properly rated probe
for your measurement.
ii
TPS2PWR1 Power Analysis User Manual
General Safety Summary
Floating. Do not float the P2220 probe reference lead to > 30 V
Use the P5120 (floatable to 600 V
CAT II or 300 V
RMS
RMS
RMS
CAT
.
III) or similarly rated, passive, high voltage probe or an appropriately
rated, high voltage differential probe when floating the reference
lead above 30 V
, subject to the ratings of such high voltage
RMS
probe.
Powering Off. The power cord provides Mains disconnect.
Replace Batteries Properly. Replace batteries only with the proper type
and rating specified.
Recharge Batteries Properly. Recharge batteries for the recommended
charge cycle only.
Use Proper AC Adapter. Use only the AC adapter specified for this
product.
Do Not Operate Without Covers. Do not operate this product with
covers or panels removed.
Avoid Exposed Circuitry. Do not touch exposed connections and
components when power is present.
Do Not Operate With Suspected Failures. If you suspect there is damage
to this product, have it inspected by qualified service personnel.
Environment. Pollution Degree 2 (As defined in IEC61010--1:2001).
Do not operate in an environment where conductive pollutants may
be present. See Appendix A of the TPS2000 Oscilloscope User
Manual for Environmental characteristics.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
TPS2PWR1 Power Analysis User Manual
iii
General Safety Summary
Provide Proper Ventilation. Refer to the manual’s installation
instructions for details on installing the product so it has proper
ventilation.
Avoid Electric Overload. To avoid injury or fire hazard, do not apply
potential to any input, including the reference inputs, that varies
from ground by more than the maximum rating for that input.
Avoid Exposed Circuitry. Do not touch exposed connections and
components when power is present.
Avoid Electric Shock. To avoid injury or loss of life, do not connect or
disconnect probes or test leads while they are connected to a voltage
source.
Keep Probe Surface Clean and Dry. To avoid electric shock and
erroneous readings, keep probe surface clean and dry.
Attached the Reference Leads Correctly. If you are using multiple
oscilloscope channels, you must attach the probe reference lead for
each channel directly to the circuit common reference that you are
measuring. These connections are required because the oscilloscope
channels are electrically isolated. They do not share a common
chassis connection. Use the shortest possible reference lead with
each probe to maintain good signal fidelity.
If Question Marks are Displayed. If a measurement display is followed
by a question mark, or a question mark is displayed instead of a
value, you have encountered an overrange condition or other error,
the reading may be invalid, and hazardous voltages may be present.
Readjust the vertical scale or position or press the front-panel
AUTOSET button.
iv
TPS2PWR1 Power Analysis User Manual
General Safety Summary
Symbols and Terms
Terms in This Manual. These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that
could result in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that
could result in damage to this product or other property.
Terms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you
read the marking.
WARNING indicates an injury hazard not immediately accessible as
you read the marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. These symbols may appear on the product:
CAUTION
Refer to Manual
Standby
TPS2PWR1 Power Analysis User Manual
Chassis Ground
v
Contacting Tektronix
Phone 1-800-833-9200*
Address Tektronix, Inc.
Department or name (if known)
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
Web site www.tektronix.com
Sales
support
Service
support
Technical
support
* This phone number is toll free in North America. After office
hours, please leave a voice mail message.
Outside North America, contact a Tektronix sales office or
distributor; see the Tektronix web site for a list of offices.
vi
1-800-833-9200, select option 1*
1-800-833-9200, select option 2*
Email: techsupport@tektronix.com
1-800-833-9200, select option 3*
1-503-627-2400
6:00 a.m. -- 5:00 p.m. Pacific time
TPS2PWR1 Power Analysis User Manual
Getting Started
Getting Started
The TPS2PWR1 Power Analysis application software adds power
measurements to a TPS2000 series oscilloscope.
Specific features include:
H Power Analysis -- Calculates the true power, reactive power,
power factor, and phase angle for a pair of voltage and current
waveforms.
H Waveform Analysis -- Calculates the RMS value, crest factor, and
frequency for a waveform.
H Phase Angles -- Calculates the phase angle between each pair of
three voltage or current waveforms.
H Harmonics -- Calculates up to 50 harmonics and can display each
harmonic’s phase angle with respect to the fundamental
frequency, its percent of the fundamental frequency, and the
THD/TDD value for the entire waveform.
H Switching Loss -- Calculates the turn-on switching loss, turn-off
switching loss, conduction loss, and total switch loss for a pair of
voltage and current waveforms.
H dV/dt and di/dt cursors -- Calculates dv/dt or di/dt between two
cursors on a waveform.
TPS2PWR1 Power Analysis User Manual
1-1
Getting Started
Basic Operation
See the TPS2000 User Manual, the P2220 Instructions, and the
P5120 Instructions for information on ratings and on basic
operations, including safety, installation, functional checks, probe
attenuation and scaling settings, and self calibration.
Ratings
TPS2000
The TPS2000 oscilloscopes are rated to 300 V CAT II signal to
common (IEC 61010) and 600 V CAT II floating reference to earth
ground reference.
P2220
The rating for the P2220 passive probe is:
1-2
X10 position: 300 V
X1 position: 150 V
CAT II probe tip to earth ground
RMS
CAT II probe tip to earth ground
RMS
The probe reference lead is rated to float 30 V max to earth ground.
P5120
The rating for the P5120 passive high voltage probe is:
1000 V
The probe reference lead is rated to float to 600 V
CAT II probe tip to earth ground.
RMS
RMS
CAT II to
earth ground.
TPS2PWR1 Power Analysis User Manual
Getting Started
Overvoltage categories
Overvoltage categories are defined as follows:
H CAT III: Distribution level mains, fixed installation
H CAT II: Local level mains, appliances, portable equipment
H CAT I: Signal level, special equipment or parts of equipment,
telecommunications, electronics
More complete product specifications are contained in the User
Manual for the TPS2000 and for the various probes.
TPS2PWR1 Power Analysis User Manual
1-3
Getting Started
Start Up
To install a TPS2PWR1 application module on your TPS2000 series
oscilloscope, follow these steps.
Observe ESD precautions.
To avoid damage to the oscilloscope
or the application module, observe
proper electrostatic discharge (ESD)
precautions. Use an ESD strap.
Insert the application key.
While the oscilloscope is turned off,
insert the power analysis application key in the indicated slot, below
and to the right of the display. The
key’s label should face up.
1-4
Power on the oscilloscope.
Wait until the display appears. Push
the side-menu OK button to continue.
ON/Standby
button
TPS2PWR1 Power Analysis User Manual
Getting Started
Probe
Voltage
PROBE COMP
CH 1
10X
CH 1 Probe
Voltage
Current
Attenuation
10X
CH 1
Attach the probes to the oscilloscope
and set up the probes.
Press the appropriate front-panel
CH 1, CH 2, CH 3,orCH 4 Menu
buttons and the appropriate Voltage
or Current side menu selection and
the Attenuation side menu selection.
Compensate the voltage probes.
For a P5120 probe, connect the
probe to channel 1 on the oscilloscope. To do this, align the slot in
the probe connector with the key on
the CH 1 BNC, push to connect,
and twist to the right to lock the
probe in place.
Connect the probe tip and reference
lead to the PROBE COMP terminals. Repeat this process for each
probe.
TPS2PWR1 Power Analysis User Manual
Degauss current probes, if required.
1-5
Getting Started
For examples of probe connections
to circuits, refer to the Application
examples provided in the Reference
section of this manual.
If you see a question mark on the
screen, you might press the frontpanel AUTOSET button or adjust
the oscilloscope as described below.
To optimize the automated measurements in the Power Analysis,
Waveform Analysis, and Phase
Angles menus, adjust the oscilloscope so that:
S the TPS2000 displays at least one
complete cycle of the waveform
1-6
S the amplitude of each waveform is
more than two divisions
S all waveform data points are on
the screen
S each cycle occupies at least one
horizontal division
TPS2PWR1 Power Analysis User Manual
Getting Started
Start the application.
Push the front-panel APPLICATION button to access the power
application functions. The power
application menu will appear in the
oscilloscope’s right-side menu. It
will present the power measurement
choices shown below.
Power applications Description
Power Analysis True power, reactive power, true power factor,
phase angles
Waveform Analysis Cyc RMS, crest factor, frequency
Phase Angles Phase angle, in degrees, between each of CH1,
CH2, and, for 4 channel models, CH3
Harmonics Fundamental RMS, Harmonics phase, frequency,
and RMS.
Switching Loss Turn-on, turn-off, conduction, and total loss
For further information on general set up of the oscilloscope, refer to
the TPS2000 User Manual.
TPS2PWR1 Power Analysis User Manual
1-7
Getting Started
Checking Module Installation
Use the following table to check that an application module is
installed. If the oscilloscope does not show the application module
menu items, do the steps in Troubleshooting Module Installation on
page 1--9.
To check this
module
TPS2PWR1 APPLICATION A menu appears on the right-side of the
Push this
front-panel button
Check for
screen with the title labelled: Power
1-8
TPS2PWR1 Power Analysis User Manual
Troubleshooting Module Installation
If the oscilloscope does not recognize the application module at
power-up, perform these steps:
1. Turn off the oscilloscope.
2. Follow the ESD precautions shown previously.
3. Remove the application module.
4. Examine the application module contacts for damage.
5. Reinsert the application module into the oscilloscope.
6. Power on the oscilloscope. If the oscilloscope still does not show
the application menu item, you have a problem with the
application module or the module slot. Contact the nearest
Tektronix service center to resolve the problem.
Getting Started
TPS2PWR1 Power Analysis User Manual
1-9
Getting Started
1-10
TPS2PWR1 Power Analysis User Manual
Reference
Power Analysis
You can use the power analysis menu functions to check out the
general power quality in your location, such as an office or industrial
plant. Find out how efficiently your facility is using its electrical
power or troubleshoot malfunctioning equipment.
To begin, hook up your TPS2000 and an appropriate passive voltage
probe (such as the P5120) and current probe (such as the A622 or
TCP305) to the portion of the power distribution system that you
wish to test, as shown below. Your specific circuit may have
different probe requirements than those just mentioned.
P3
P2
P1
Neutral
S3
S2
S1
WARNING. Do not float the P2220 probe reference lead to > 30
. Use the P5120 (floatable to 600 V
V
RMS
CAT III) or similarly rated, passive, high voltage probe or an
appropriately rated, high voltage, differential probe when floating
the reference lead above 30 V
RMS
voltage probe.
TPS2PWR1 Power Analysis User Manual
CAT II or 300 V
RMS
RMS
, subject to the ratings of such high
2-1
Power Analysis
Push the Power Analysis button to show the Power Analysis Menu.
The osclloscope will display the voltage and current source
waveforms and display related measurement values. It will also
automatically set up and display a Math waveform of the instantaneous power function (V*A).
These power analysis functions analyze the interaction of the source
current and voltage waveforms. These operations require the use of
both a voltage and a current probe.
2-2
TPS2PWR1 Power Analysis User Manual
Power Analysis
The menu includes the following choices and values:
Menu item Description
Sources Selects a channel pair. On a four-channel oscilloscope,
choose either: (CH1 and CH2) or (CH3 and CH4).
On a two--channel oscilloscope, the sources are fixed as
CH1 & CH2.
(CH1 and CH2) and (CH3 and CH4) should be pairs of
(voltage, current) waveforms. The math multiply waveform
is always set to use the selected sources.
True Power Displays the true power. Calculated by taking the mean
value of the math (V*A) waveform.
Reactive Power Displays the reactive power. (Volts--Amps Reactive).
Calculated by multiplying together the RMS value of the
voltage waveform, the RMS value of the current waveform,
and the sine of the phase angle. The computation of phase
angle is explained in the phase angle section of the
manual.
TPS2PWR1 Power Analysis User Manual
2-3
Power Analysis
Menu item Description
True Power
Factor
Phase Angle Displays the angle (--90_to +90_) whose cosine is the true
Displays the ratio (0 to 1) of true power to apparent power.
Apparent power is calculated by multiplying the RMS value
of the voltage waveform by the RMS value of the current
waveform.
Typically, a higher power factor means more efficient use of
energy.
A purely resistive circuit would have a power factor of 1.0.
A purely inductive one would have a power factor of 0.0.
power factor. For sinusoidal waveforms, this value is the
same as the phase angle measured in the Phase Angles
menu. For non--sinusoidal waveforms, the two phase angle
measurements may differ.
The angle is positive if the CH1 waveform (typically
voltage) leads the CH2 waveform (typically current). The
angle is negative if the CH1 waveform lags behind the CH2
waveform.
2-4
TPS2PWR1 Power Analysis User Manual
Power Analysis
Sample Results
Next analyze your results. The figures below show stylized
examples.
Voltage
Current
Power
Power factor = 1.
Phaseangle=0
_
.
Voltage and current are in
phase.
Resistive circuit
Voltage
Current
Power
Power factor = 0.9.
Phaseangle=0
_
.
Voltage and current are in
phase.
Unbalanced current typical of
an adjustable speed motor drive.
Voltage
Current
Power
Power factor = 0.707.
Phase angle = 45
Current lags voltage by 45
_
.
_
.
Circuit is partially inductive.
Voltage
Current
Power
Powerfactor=0.9.
Phaseangle=0
_
.
Voltage and current are in
phase.
Unbalanced current typical of a
switching power supply.
TPS2PWR1 Power Analysis User Manual
2-5
Power Analysis
Operating Tips
H When you enter the Power Analysis menu, the oscilloscope
automatically turns on the channels selected as sources. It also
turns on the math multiply (V*A) power waveform. It does not
make any other changes to your setup.
H The power measurements in this menu are based on all the
complete cycles found in the voltage waveform record.
H The following illustration further explains the values used in this
menu.
True power = volts
* amps in watts
Power factor
=cos
Power angle
between voltage and
current
Apparent power =
volts * amps in
volt--amps
Reactive power =
volts * amps in
volts--amps--reactive
2-6
TPS2PWR1 Power Analysis User Manual
Power Analysis
H If a measurement display is followed by a question mark, or a
question mark is displayed instead of a value, you have
encountered an overrange condition or other error, the reading
may be invalid, and hazardous voltages may be present. Readjust
the vertical scale or position or press the front-panel AUTOSET
button.
NOTE. All power application measurements require an installed
TPS2PWR1 application key.
TPS2PWR1 Power Analysis User Manual
2-7
Power Analysis
2-8
TPS2PWR1 Power Analysis User Manual
Waveform Analysis
You can use the waveform analysis menu functions to measure the
crest factor and further characterize your power quality situation.
This is useful in offices or manufacturing plants where the load on a
particular branch may vary, affecting the quality of the power to the
attached loads.
The following figure shows example setups for measuring the crest
factor for either voltage or current.
TPS2PWR1 Power Analysis User Manual
2-9
Waveform Analysis
P3
P2
P1
S3
S2
S1
A622
P5120
WARNING. Do not float the P2220 probe reference lead to > 30
. Use the P5120 (floatable to 600 V
V
RMS
CAT II or 300 V
RMS
CAT III) or similarly rated passive high voltage probe or an
appropriately rated high voltage differential probe when floating the
common lead above 30 V
, subject to the ratings of such high
RMS
voltage probe.
RMS
2-10
TPS2PWR1 Power Analysis User Manual
Waveform Analysis
Push the Waveform Analysis button to show the Waveform
Analysis Menu on the right side of the screen and the source voltage
or current waveform to the left of the menu. The oscilloscope will
display the source waveform and measurement values.
These waveform analysis functions provide measurements to help
you analyze individual waveforms. These operations require use of
an individual voltage or current probe.
TPS2PWR1 Power Analysis User Manual
2-11
Waveform Analysis
The menu offers the following choices and values.
Menu item Description
Source Selects the channel. Choose between: CH1 or CH2 or
Cyc RMS Displays the RMS value of the first complete cycle of the
Crest Factor Displays the ratio of the maximum value of the entire
MATH.
On 4-channel models, you can also choose CH3 or CH4
selected waveform.
waveform to the RMS value of the first complete cycle.
The ratio of the signal’s peak value to the RMS value.
It is 1.414 for a pure sine wave and 1.0 for a 50% duty
cycle square wave.
The voltage crest factor indirectly specifies the purity of the
AC supply.
The current crest factor indirectly specifies the ability of the
load to draw high AC peak currents.
2-12
Freq Displays the frequency (inverse of the period of the first
complete cycle).
TPS2PWR1 Power Analysis User Manual
Waveform Analysis
Sample Results
Next, analyze your results. The figures below show stylized
examples.
Crest factor = 1.41.
Clean sine wave.
Crest factor > 1.41.
Current spike.
Typical of non--linear loads such as
switching power supplies.
TPS2PWR1 Power Analysis User Manual
Crest factor < 1.41.
Topped-out voltage wave.
Typical of power supplies with
non--linear loads.
2-13
Waveform Analysis
Operating Tips
H Unlike some other menus in the TPS2PWR1 Power Application,
the Waveform Analysis menu does not turn any channels on or
off, or otherwise change your setup.
H The following illustration further explains the values used in this
menu.
Peak amplitude
RMS amplitude
Reference
point
Period
(Frequency = 1 / period)
Crest factor = peak
amplitude / RMS
amplitude
H If a measurement display is followed by a question mark, or a
question mark is displayed instead of a value, you have
encountered an overrange condition or other error, the reading
may be invalid, and hazardous voltages may be present. Readjust
the vertical scale or position or press the front-panel AUTOSET
button.
NOTE. All power application measurements require an installed
TPS2PWR1 application key.
2-14
TPS2PWR1 Power Analysis User Manual
Phase Angles
The Phase Angle menu functions help you look at the efficiency of
applications such as power transmissions in industrial, 3--phase
applications.
For example, you might use them to investigate whether out-ofphase voltage is contributing to overheating in a three-phase motor.
Because the channels are independently isolated, the reference lead
for each probe must be separately connected to the reference point of
the circuit under test.
The figure below shows one way of hooking up the oscilloscope to
measure the phase angles of voltage going into a motor’s variable
speed drive.
TPS2PWR1 Power Analysis User Manual
2-15
Phase Angles
P5120
1 23
Neutral
WARNING. Do not float the P2220 probe reference lead to > 30
. Use the P5120 (floatable to 600 V
V
RMS
CAT II or 300 V
RMS
RMS
CAT III) or similarly rated passive high voltage probe or an
appropriately rated high voltage differential probe when floating the
common lead above 30 V
, subject to the ratings of such high
RMS
voltage probe.
2-16
TPS2PWR1 Power Analysis User Manual
Phase Angles
Push Phase Angles to bring up the Phase Angle Menu. The menu
will display the phase angle between any two of the three channels in
a three-phase electrical system.
Simplify your measurements by using three voltage or current probes
and a 4--channel version of the TPS2000. You can also use a
2-channel instrument if you move your probes around to make the
measurements.
TPS2PWR1 Power Analysis User Manual
2-17
Phase Angles
It displays the following measurements:
Menu item Description
Source CH1 --> CH2,
CH2 --> CH3,
CH1 --> CH3
If you have a two channel oscilloscope, the menu will only
display the phase difference between channels 1 and 2.
You will need to move the probes around to make
three-phase measurements.
The angles, in degrees, range from --180_to +180_.
The angle is positive if the lower-numbered channel’s
waveform leads the higher-numbered channel’s waveform.
It is negative if the lower-numbered channel’s waveform
lags rather than leads. For example, the angle is positive if
the CH1 waveform leads the CH2 waveform. The angle is
negative if the CH1 waveform lags behind the CH2
waveform.
2-18
TPS2PWR1 Power Analysis User Manual
Phase Angles
The figures below show stylized example results with a perfect 120
degrees separating each phase and with imperfect separations.
CH1
Phase A
CH2
Phase B
+
U
--
_
125
CH1--CH2
TPS2PWR1 Power Analysis User Manual
_
125
CH2--CH3
CH3
Phase C
_
110
CH3--CH1
2-19
Phase Angles
Operating Tips
H This menu computes phase angles. To measure phase angle as the
H The following illustration further explains the values used in this
angle whose cosine is the true power factor, use the Power
Analysis menu.
menu.
Phase = (delay/period) * 360
If (phase > 180_) then
phase = phase -- 360
Delay
Period
_
_
)
CH 1 --> CH 3
Phase
CH 3
CH 1
CH 1 --> CH 2
Phase
CH 2
CH 2 --> CH 3
Phase
H If a measurement display is followed by a question mark, or a
question mark is displayed instead of a value, you have
encountered an overrange condition or other error, the reading
may be invalid, and hazardous voltages may be present. Readjust
the vertical scale or position or press the front-panel AUTOSET
button.
NOTE. All power application measurements require an installed
TPS2PWR1 application key.
2-20
TPS2PWR1 Power Analysis User Manual
Harmonics
You can use the Harmonics menu functions to display the frequency
spectrum of the source waveform and the associated measurement
values and perform in-depth troubleshooting of power quality
problems.
The figures below show example setups for measuring either voltage
or current harmonics in a building’s wiring.
Neutral
P1
P2
P3
Switch
mode
power
supply
P3
P2
P1
S1
S2
S3
S3
S2
S1
Neutral
WARNING. Do not float the P2220 probe reference lead to > 30
V
. Use the P5120 (floatable to 600 V
RMS
CAT II or 300 V
RMS
RMS
CAT III) or similarly rated passive high voltage probe or an
appropriately rated high voltage differential probe when floating the
common lead above 30 V
, subject to the ratings of such high
RMS
voltage probe.
TPS2PWR1 Power Analysis User Manual
2-21
Harmonics
Push the Harmonics button to bring up the Harmonics menu. The
oscilloscope will display the frequency spectrum of the source
waveform and the associated measurement values.
2-22
TPS2PWR1 Power Analysis User Manual
Harmonics
The menu offers the following choices and values:
Menu item Description
Source Choose a channel to measure.
Available choices are: CH1, CH2, and, on four--channel
oscilloscopes, CH3, or CH4.
Use voltage or current waveforms.
Setup Choose either “Automatic” (default) or “Manual“.
Show <value> Choose the harmonics to display.
<value> is “All Harmonics”, “Odd Harmonics”, or “Even
Harmonics”
Save Harmonics Saves the harmonics data to a file on a CompactFlash
card.
The file will be auto-named using the HM1234.csv format.
The file will be stored in the current folder on the
CompactFlash card.
The file will contain the following for each of the 50
harmonics, and more:
Magnitude (amplitude),
Percent of the fundamental harmonic,
Frequency, and
Phase angle
Doing a save will save the harmonics waveform and the
underlying time domain waveform.
You will typically view the contents of the harmonics .CSV
file on a personal computer. You cannot recall the file to the
oscilloscope.
TPS2PWR1 Power Analysis User Manual
2-23
Harmonics
The Automatic setup control directs the oscilloscope to save your
settings when you enter the harmonics menu, and restores them
when you leave.
The automatic setup does the following:
H Sets the source channel vertical position to zero.
H Sets the source channel vertical coupling to DC and bandwidth
limit to on.
H Adjusts the source channel vertical scale so the signal amplitude
is at least two divisions.
H Sets the trigger source to the source channel.
H Sets the trigger type to edge, slope to rising, and coupling to DC.
H Adjusts the trigger level to mid-level of the source channel
signal.
H Adjusts the horizontal scale to capture three to five cycles of the
source channel.
H Sets the acquisition mode to average, with 16 waveforms per
average.
2-24
TPS2PWR1 Power Analysis User Manual
Harmonics
Operating Tips
H The oscilloscope will calculate the first 50 harmonics if you
choose “All Harmonics” and the first 25 odd or even harmonics
otherwise.
H The oscilloscope will show:
H the number of the selected harmonic
H the frequency of the selected individual harmonic
H the magnitude and percent of the fundamental for the selected
harmonic
H the phase angle of the selected individual harmonic relative to
the fundamental
H To see details on individual harmonics, turn the oscilloscope
multipurpose knob. Turn the knob clockwise to increase the
selected harmonic number (e.g. 1, 2, 3, 4, ...) or turn it counterclockwise to decrease the selected harmonic number.
H The oscilloscope will display 13 consecutive harmonics at a time.
To see harmonics not currently displayed, simply turn the
multipurpose knob clockwise beyond the first one shown to see a
harmonic that follows the last one currently displayed or
counterclockwise beyond the first one shown to see a harmonic
that precedes the first one currently displayed.
TPS2PWR1 Power Analysis User Manual
2-25
Harmonics
H The harmonics application only displays harmonics data on
signals with frequencies of 40 Hz to 450 Hz. To view the
harmonics of a signal with a fundamental frequency outside those
ranges, or to see spectrum information for frequencies that are
not harmonics of the fundamental, use the FFT function in the
MATH menu. The FFT function does not provide the same
display as the harmonics application.
H If the harmonics menu setup control is set to Automatic, then
when you enter the harmonics menu, the oscilloscope will adjust
various settings to optimize the harmonics display. When you
exit the menu, the oscilloscope will restore itself to the previous
settings.
H Manual Setup: If you choose to manually set up your waveform
for the harmonics functions, the oscilloscope will not return to
your prior setup when exiting the harmonics menu.
2-26
TPS2PWR1 Power Analysis User Manual
Harmonics
H The following illustration further explains the values used in this
menu.
RMS Amplitude of
fundamental
Fundamental
frequency
Total harmonic distortion = ratio of
power in harmonics to power in
fundamental
2
3
4
RMS Amplitude of
selected harmonic
5
7
9
H If a measurement display is followed by a question mark, or a
question mark is displayed instead of a value, you have
encountered an overrange condition, the reading is invalid, and
hazardous voltages may be present. Readjust the vertical scale or
press the front-panel AUTOSET button.
NOTE. All power application measurements require an installed
TPS2PWR1 application key.
TPS2PWR1 Power Analysis User Manual
2-27
Harmonics
Sample Results
Next, analyze your results. The figures below show some examples.
Clean harmonics for a line voltage
signal with no secondary harmonics
andnoload.
V(RMS) = 120 V
THD = 0
5th, 7th, 11th, and 13th harmonics
for the voltage of an adjustable
speed drive of a motor, with 6
rectifiers.
V(RMS) = 120 V
THD = 135%
2-28
Odd-ordered harmonics (3rd, 5th,
7th, 9th, 11th, and 13th) for the
voltage from a switched power
supply. V(RMS) = 120 V
THD = 90%
TPS2PWR1 Power Analysis User Manual
Switching Loss
Use the switching loss functions to characterize power losses in
IGBT switching power supplies and similar circuits, as they switch
on and off. Switching loss operations require the use of a voltage and
a current probe.
Switching loss measurements can characterize the efficiency of an
adjustable speed drive.
The figure below shows an example setup for measuring switching
loss. Place an isolated, floating voltage probe, like the P5120, or a
differential voltage probe, like the P5205 probe with an 1103 power
supply, across the devices collector and emitter. Place a current
probe, like the A622, to measure the collector current.
A622
V
C
ce
G
E
WARNING. Do not float the P2220 probe reference lead to > 30
. Use the P5120 (floatable to 600 V
V
RMS
CAT III) or similarly rated passive high voltage probe or an
appropriately rated high voltage differential probe when floating the
common lead above 30 V
, subject to the ratings of such high
RMS
voltage probe.
TPS2PWR1 Power Analysis User Manual
P5120
CAT II or 300 V
RMS
RMS
2-29
Switching Loss
WARNING. To avoid an electric shock, do not use probes that require
a ground connection, such as the Tektronix P5200 High Voltage
Differential Probe, with the TPS2000 series oscilloscopes. The
P5200 High Voltage Differential Probe requires an oscilloscope with
grounded inputs and the TPS2000 series oscilloscopes have floating
inputs (isolated inputs).
Push the Switching Loss button to show the Switching Loss Menu.
The oscilloscope will display the voltage and current source
waveforms, related measurement values, and will automatically set
up and display a Math waveform of the instantaneous power function
(V*A).
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TPS2PWR1 Power Analysis User Manual
Switching Loss
Page 1 of the Switching Loss menu offers the following choices:
Menu item Description
Sources Choose (CH1 & CH2) or (CH3 & CH4) where each pair
contains a voltage and a current waveform. If you have a
two channel oscilloscope, the menu will only display the
(CH1 & CH2) choice.
VSAT Enter the saturation voltage across the switch when the
device-under-test (DUT) is on. The DUT’s data sheet may
contain this value.
Enter this value with the front-panel multipurpose knob.
Use Default
Levels
Save Meas Push to save the switching loss measurements to a CSV
Push to instruct the oscilloscope to use default levels for
determining the turn-on, conduction, and turn-off regions.
file on a CompactFlash card.
TPS2PWR1 Power Analysis User Manual
2-31
Switching Loss
Page 2 of the Switching Loss Menu offers the following choices:
Menu item Description
Turn-on Start Push this button and use the multipurpose knob to move
Turn-on End Push this button and use the multipurpose knob to move
Turn-off Start Push this button and use the multipurpose knob to move
Turn-off End Push this button and use the multipurpose knob to move
the cursor to select a voltage waveform edge percentage
level other than the 90% default
the cursor to select a voltage waveform edge percentage
level other than the 10% default
the cursor to select a voltage waveform edge percentage
level other than the 10% default
the cursor to select a current waveform edge percentage
level other than the 10% default
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TPS2PWR1 Power Analysis User Manual
Switching Loss
Page 3 of the Switching Loss Menu offers the following choices:
Menu item Description
Acquire
Continuously
Push this button to instruct the oscilloscope to continuously
acquire waveforms, calculate measurements, and display
them.
Stop After N
Meas
Units Choose whether to display the measurement results in
Push this button and use the multipurpose knob to set the
number of measurements. In this mode, the oscilloscope
performs measurements on N different acquisitions and
then stops. The oscilloscope saves the measurements
internally. It displays the averages of the measurements on
the screen. You can save the details of each of the N
measurements to a file by pushing Save Meas. on page 1
of the Switching Loss menu.
watts or joules. You might choose watts to determine how
much power is being used by the device-under-test and
joules to compare the device to its specification.
TPS2PWR1 Power Analysis User Manual
2-33
Switching Loss
The following switch loss measurements are displayed on the
graticule:
Menu item Description
Turn-on Loss Displays the power loss of the device in watts or joules
Turn-off Loss Displays the power loss of the device in watts or joules
Conduction Loss Displays the power loss of the device in watts or joules
when the device is transitioning between its off and on
states.
Turn-on loss is the area under the VA waveform during the
time period between turn-on start and turn-on stop.
when the device is transitioning between its on and off
states.
Turn-off loss is the area under the VA waveform during the
time period between turn-off start and turn-off stop.
when the device is conducting in its on state.
Conduction loss is calculated by multiplying the current
waveform by the saturation voltage of the device, and
integrating over the time period defined by the edge levels.
The algorithm uses the user-entered saturation voltage,
rather than the voltage waveform, because the level of the
voltage waveform is usually too small to measure during
conduction.
2-34
Total Loss Displays the sum of the turn-on, turn-off, and conduction
losses.
TPS2PWR1 Power Analysis User Manual
Switching Loss
Operating Tips
H The switching loss algorithm measures power over three time
periods: turn-on, conduction, and turn-off. The algorithm
determines the three time periods by finding the four time points
that bound them. These are:
H Turn-on start is a level (default = 90%) of the falling edge of
the voltage waveform.
H Turn-on stop is a level (default = 10%) of the falling edge of
the voltage waveform.
H Turn-off start is a level (default = 10%) of the first rising edge
of the voltage waveform.
H Turn-off stop is a level (default = 10%) of the first falling
edge of the current waveform that occurs after the turn-off
start. Unlike the other time points, which are determined from
the voltage waveform, this time point is determined from the
current waveform.
H The following illustration further explains the values used in this
menu.
Turn--on start
Turn--on stop
Saturation
voltage
Turn--on
region
Conduction
region
TPS2PWR1 Power Analysis User Manual
Turn--off start
I
Turn--off stop
V
VA Math
Turn--off
region
2-35
Switching Loss
H You can use page 2 of the menu to turn on cursors that show
Watts and Joules:
The losses for one switching cycle are calculated in joules. One joule
is one Volt--Amp--second. By default, the losses are reported in
watts. You can choose to have them reported in joules. The watts
value is calculated by multiplying the joules value by the trigger
frequency, which is assumed to be the switching frequency.
where the percentage levels fall on the waveforms. Use the
multipurpose knob to move the cursors and change the
percentage levels.
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TPS2PWR1 Power Analysis User Manual
Switching Loss
Setup Sequence:
Start by setting up your oscilloscope to view one switching cycle. A
typical setup sequence might include:
1. Set up channel 1 with a voltage probe. Use the channel menu to
set the voltage probe attenuation. Connect the voltage probe tip
to the IGBT collector. Connect the reference lead to the emitter.
2. Set up channel 2 with a current probe. Use the channel menu to
set the current probe scale factor. Connect the current probe in
the collector leg. Alternatively, you may connect the current
probe in the emitter leg. However, the emitter current includes
the gate drive current, which may be significant.
3. Set the trigger source to channel 1.
4. Press the AUTOSET button to get a preliminary setup.
5. Set the trigger slope to Falling.
6. If any of the signals are noisy, you may want to press the
front-panel ACQUIRE button and then the side-menu Average
menu item.
7. Press the front-panel APPLICATION button and then the
side-menu Switching Loss menu item.
8. Adjust the horizontal scale and position to show one falling edge
and one rising edge of the voltage waveform.
9. Adjust channel 1, channel 2, and math vertical scale and vertical
position so that each waveform amplitude is more than two
divisions, but is not clipped.
TPS2PWR1 Power Analysis User Manual
2-37
Switching Loss
The oscilloscope will display the loss measurements in the lower
part of the graticule area. If the waveform information needed for a
measurement is not on the screen, the oscilloscope will display a
question mark in place of the measurement.
Measurement Strategies:
Different power supplies require different measurement strategies.
If your supply has a constant switching frequency, a constant duty
cycle, and conduction time is relatively short, the setup described
earlier should give you good results.
If your signal has a constant switching frequency and a constant duty
cycle but conduction time is long relative to turn-on and turn-off, it
may not be possible to accurately measure all three regions at the
same time. In this case, you can use the horizontal position and
horizontal scale controls to zoom and pan to the turn-on region and
measure the turn-on loss. Next, zoom and pan to the turn-off region
and measure the turn-off loss. Finally, change the setup to display the
full cycle and measure the conduction loss.
2-38
TPS2PWR1 Power Analysis User Manual
Switching Loss
If your signal has a constant switching frequency but a varying duty
cycle, you may be able to use the Stop After N Measurements
feature to obtain good measurements. Do the following:
1. Set up the oscilloscope so that a single acquisition covers events
with the longest duty cycle.
2. Go to page 3 of the Switching Loss menu and select the Stop
After N Measurements mode.
3. Rotate the multipurpose knob to set N to a value large enough to
collect a good sample of measurements with a variety of duty
cycles. This may require experimentation.
4. Push the RUN button.
5. After the oscilloscope completes the specified number of
measurements, examine the average values reported on the
screen. To examine the results from individual acquisitions, go to
page 1 of the switching loss menu and push the Save Meas
button. This saves the detailed data to a .CSV file on a CompactFlash card.
TPS2PWR1 Power Analysis User Manual
2-39
Switching Loss
H If a measurement display is followed by a question mark, or a
NOTE. All power application measurements require an installed
TPS2PWR1 application key.
question mark is displayed instead of a value, you have
encountered an overrange condition or other error, the reading
may be invalid, and hazardous voltages may be present. Readjust
the vertical scale or position or press the front-panel AUTOSET
button.
2-40
TPS2PWR1 Power Analysis User Manual
dY/dt Measurements
Use this menu to measure the slope (rate of change) of signals.
Y can refer to voltage, current, or a product of voltage and/or
current.
The figure below shows an example setup for measuring dY/dt
results.
L
N
E
40 KHz
clock
WARNING. Do not float the P2220 probe reference lead to > 30
. Use the P5120 (floatable to 600 V
V
RMS
CAT III) or similarly rated passive high voltage probe or an
appropriately rated high voltage differential probe when floating the
common lead above 30 V
, subject to the ratings of such high
RMS
voltage probe.
TPS2PWR1 Power Analysis User Manual
A622
P5120
CAT II or 300 V
RMS
RMS
2-41
dY/dT Measurements
Push the Cursor front-panel button and the Type buttoninthe
resulting Cursor side menu to select the dY/dt measurement. The
measurement will appear in the lower-left graticule area.
Adjust the cursors to vary the portion of the waveform over which to
measure. The dY/dt measurements are only available when the
power application key is installed.
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TPS2PWR1 Power Analysis User Manual
P5120 Specifications
The P5120 warranted specifications of Table 2--1 that appear in
boldface type are specifications checked in the Performance
Verification section of the P5120 Passive High-Voltage Probe
Instructions (Tektronix part number 071-1463-00). Specifications
that are not warranted are typical (Tables 2--2 and 2--3) and are
provided as general information for your convenience.
The specifications apply to a P5120 probe installed on a Tektronix
TPS2000 series oscilloscope. The instrument must have a warm-up
period of at least 20 minutes and be in an environment that does not
exceed the limits described in Table 2--4.
Table 2- 1: Warranted electrical specifications
Attenuation
(DC coupled system)
Bandwidth
(--3 dB, DC coupled system)
Maximum Rated Input Voltage IEC 1010-1 Installation Category
Between probe tip and probe reference
or between probe tip and earth ground
(Refer to Figure 2--1)
Between probe reference and earth ground
(Refer to Figure 2--2)
Safety UL 61010B--2--031; 2003
IEC Installation Category Category II
IEC Pollution Degree Degree 2
20X, ±2%
DC to 200 MHz (TPS2024)
DC to 100 MHz (TPS2012, TPS2014)
II III
1000 600
600 300
CSA 22.2 No. 1010.2--031, 1994
EN 61010-031 2002
TPS2PWR1 Power Analysis User Manual
2-43
P5120 Specifications
1,000 V
600 V
300 V
100 V
10 V
Voltage (V )
1V
Category I & II
Category III
10 Hz
100 Hz
P5120 Voltage derating
1KHz
10 KHz
Frequency (Hz)
Figure 2- 1: Maximum voltage derating curves (V
reference or earth ground
100 KHz
RMS
1MHz
, DC coupled), probe tip to
10 MHz
100 MHz
200 MHz
2-44
TPS2PWR1 Power Analysis User Manual
P5120 Specifications
1,000 V
600 V
300 V
100 V
Voltage (V )
10 V
1V
Category I & II
Category III
10 Hz
100 Hz
P5120 Voltage derating
1KHz
10 KHz
Frequency (Hz)
Figure 2- 2: Maximum voltage derating curves (V
reference to earth ground
100 KHz
RMS
1MHz
, DC coupled), probe
10 MHz
100 MHz
200 MHz
TPS2PWR1 Power Analysis User Manual
2-45
P5120 Specifications
Table 2- 2: Typical electrical characteristics
Rise Time (System)
Checked using optional BNC adapter
< 3.6 ns (TPS2012, 2014)
< 2.2 ns (TPS2024)
Typical
Input Resistance (System)
5MΩ
SeeFigure2--3
Input Phase (System) (See Figure 2--4)
Compensation Range 15 pF to 25 pF
Input Capacitance (System)
11.2 pF
Probe connected to instrument and properly
compensated. Checked at 1 MHz
10 MΩ
5MΩ
1MΩ
100 kΩ
10 kΩ
OHMS
1kΩ
P5120 Impedance
100 Ω
10 Ω
1 Ω
10 Hz
100 Hz
1KHz
Figure 2- 3: Typical input impedance
2-46
10 KHz
Frequency (Hz)
100 KHz
1MHz
10 MHz
100 MHz
TPS2PWR1 Power Analysis User Manual
200 MHz
P5120 Specifications
0
-- 1 0
-- 2 0
-- 3 0
-- 4 0
-- 5 0
Degrees
-- 6 0
-- 7 0
-- 8 0
-- 9 0
-- 100
10 Hz
100 Hz
1KHz
Figure 2- 4: Typical input phase
P5120 Phase
10 KHz
Frequency (Hz)
100 KHz
1MHz
10 MHz
100 MHz
200 MHz
TPS2PWR1 Power Analysis User Manual
2-47
P5120 Specifications
Table 2- 3: Typical mechanical characteristics
Net Weight
(including accessories)
Cable Length 3m(+--3cm)(9.84ft)
0.26 kg (0.57 lb)
Table 2- 4: Environmental specifications
Temperature Operating: 0 °Cto+50°C
(+32 °F to +122 °F)
Nonoperating: --40 °Cto+71°C
(--40°F to +159 °F)
Humidity Operating:
High: 50 °C (122 °F)/60% RH
Low: 30 °C(86°F)/60% RH
Nonoperating:
High: 55 °Cto71°C (131 °F to 160 °F),
60% RH
Low: 0 °Cto30°C(32°Fto86°F),
≤ 90% RH
Transportation Tektronix Standard 062-0937-00 Revision C
Altitude Operating: 4,600 m (15,092 ft)
Nonoperating: 12,192 m (40,000 ft)
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TPS2PWR1 Power Analysis User Manual
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