IEEE Power Electronics Magazine - March 2020 - 34

Voltage Step

Frequency Step
Frequency 1 Frequency 2 Frequency 3

Voltage 1
Voltage 2
Voltage 1

Time 1

Time 2

Time 3

Time 1

Time 2

Time 3

Step 1

Step 2

Step 3

Step 1

Step 2

Step 3

FIG 9 An example of software-controlled waveform inputs that can be set up using the Preen AFV-P Series. (Source: AC Power
Corp.; used with permission.)

clean power with a distortion of less than 0.3% at 50/60 Hz,
is programmable for a full range of tests. For instance, it is
possible to simulate real-world conditions by changing voltage and frequency by ramping up or down or by a series of
distinct steps in any combination of voltage and frequency.
Further aiding analysis, the unit can then display the output
waveform and precise measurement readings [5].
Users can also set up and trigger power line disturbances
for the EUT. These include transient events, such as sags,
surges, and dropouts of selected severity and duration, which
according to IEC 61000-4-11 are to occur at zero-degree crossing. However, it is also possible to set the events to occur at
any desired degree from 0° to 359°. To meet the requirements
for IEC 61000-4-11 precompliance tests, the Preen AFV-P
Series features a fast response time of less than 300 µs as well
as the ability to automatically record test results.
Certain motor-type products or appliances may require
higher inrush current (or start-up current) upon start-up.
The Preen AFV-P Series is capable of optional 150% overload capacity within 1 s. That may help if the motor has
certain inrush current within a couple of milliseconds and
back to the rated current.
The Preen AFV-P Series can be controlled from an
attached computer or over the network using the supplied
software and a LabVIEW driver (see Figures 8 and 9). It can
also be controlled directly via the built-in graphical HMI
on its 5-in touchscreen with no additional programming.
A rotary knob is supplied on the front panel for precision
adjustments. All in all, the Preen AFV-P Series offers a complete test solution for ac and dc power quality and precompliance with IEC 61000-4-11 requirements. Using this or similar
equipment can potentially save product development time.

and IEC 61000-4-28 addresses the immunity of devices to
variations in the frequency of their ac power sources. MILSTD-704F defines power characteristics for aircraft systems. One solution to achieve stable power quality is to use
a programmable ac power source that meets the parameters outlined by the test standards, satisfying the conditions
for critical aerospace, defense, and industrial applications.

About the Authors
Brian Hsu (brian.hsu@acpower.net) received his M.S.
degree in mechanical engineering from Taiwan University,
Taipei City, in 2003. He is a product marketing manager at
AC Power Corporation, Taipei, Taiwan, and a coauthor of
two patents for an electrical energy management device:
U.S. Patent number US20 050 118 472 and Taiwan Patent
number TW200 520 282.
Jorge Velazquez (jorge.vela@acpower.net) received his
B.S. degree in electrical engineering from California State
Polytechnic University, Pomona, in 2018. He is a field applications engineer at AC Power Corporation, Taipei, Taiwan.

References
[1] Handbook on EN 61000-4-14 Mains Voltage Fluctuations, REO (UK)
Ltd., Craven Arms, U.K., 2007, p. 2. [Online]. Available: https://www.reo
.co.uk/en_61000-4-11_voltage_variations
[2] A Practical Guide for EN 61000-4-11 Testing and Measurement Techniques, REO (UK) Ltd., Craven Arms, U.K., 2007, pp. 2-12. [Online]. Available: https://www.reo.co.uk/en_61000-4-11_voltage_variations
[3] A Practical Guide for EN61000-4-28: Power Frequency Variation, REO
(UK) Ltd., Craven Arms, U.K., pp. 2-26. [Online]. Available: https://www.reo
.co.uk/en_61000-4-28_immunity_to_power_frequency_variatio
[4] Department of Defense Handbook: Guidance for Test Procedures for
Demonstration of Utilization Equipment Compliance to Aircraft Electri-

Summary

cal Power Characteristics Single Phase, 400 Hz, 115 Volt, HDBK-704-2,

Critical applications in aerospace, defense, and industrial
segments demand reliable quality power sources. Test standards including IEC 61000-4-11, IEC 61000-4-14, IEC 610004-28, and MIL-STD-704F define power quality and the test
procedures. IEC 61000-4-11 is the standard for testing
immunity to voltage variations like dips, dropouts, sags, and
interruptions; IEC 61000-4-14 tests for voltage fluctuations;

U.S Department of Defense, Washington, D.C., 2004, pp. 2-97. [Online]. Avail-

IEEE POWER ELECTRONICS MAGAZINE

z March 2020

able: http://everyspec.com/MIL-HDBK/MIL-HDBK-0700-0799/download.
php?spec=MIL-HDBK-704-2.014611.PDF
[5] AFV-P Series: High-Performance Programmable AC Power Source, AC
Power Corp., Taipei, Taiwan, 2019. [Online]. Available: https://www.preenpower
.com/en/product/1560842500046/1570244319172

https://www.reo.co.uk/en_61000-4-11_voltage_variations https://www.reo.co.uk/en_61000-4-11_voltage_variations https://www.reo.co.uk/en_61000-4-11_voltage_variations https://www.reo.co.uk/en_61000-4-28_immunity_to_power_frequency_variatio https://www.reo.co.uk/en_61000-4-28_immunity_to_power_frequency_variatio file:///C:/Users/lulu1/Downloads/MIL-HDBK-704-2.PDF file:///C:/Users/lulu1/Downloads/MIL-HDBK-704-2.PDF https://www.preenpower.com/en/product/1560842500046/1570244319172 https://www.preenpower.com/en/product/1560842500046/1570244319172

IEEE Power Electronics Magazine - March 2020

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