DEI DTS-1600A Datasheet

DTS-1600A

Dielectric Test
System

The use of Pulse Width Modulated
(PWM) types of adjustable speed
drives (ASD) in the electric motor in­dustry has caused an increased inci­dence of premature wire insulation fail­ure. The DTS-1600A is an integrated
test system designed to test the failure
behavior of insulation by simulating,
under controlled and accelerated con­ditions, the electrical and ther mal
stresses that characterize PWM
(inverter) motor controllers.

The DTS-1600A test system is de­signed to vary and monitor the electri­cal and thermal test parameters for up
to five samples simultaneously, includ­ing voltage, current, pulse width, fre­quency, voltage rate-of-rise time, duty
cycle and temperature. The control
and monitoring of these parameters
allows the user to study the insulation
failure mechanisms common to PWM
applications. This data can then be
used in the development of new motor
designs and insulation that will over­come these failure modes.

Compared to testing with an inverter,
the DTS-1600A can reduce the test
time from days per sample to minutes
per sample (time-to-failure with the
DTS-1600A is typically 1,000 times
faster than with an inverter), dramati­cally reducing research and develop­ment time for new insulating materials.
Equally important, full control over the
electrical and thermal test parameters
provides a reproducible test environ-

The Pulse Of The Future

Directed Energy, Inc.

• 2401 Research Blvd., Suite 108 • Fort Collins, CO 80526

TEL: [phone] • FAX: [phone] • EMAIL: [e-mail] • Internet: http://www.directedenergy.com

• 5-Channel 3,200V Pulsed Test

System for Accelerated Breakdown
Testing of Motorettes, Twisted-Pair
and Dielectric Materials

• Variable Output Voltage, Pulse Rate-

of-Rise Time, Frequency, Duty Cycle
and Temperature

• Graphical User Interface and

Computer Control and Logging Of
Test and Oven Parameters

DTS-1600A Dielectric Test System

OPERATIONAL OVERVIEW

The DTS-1600A is designed to meet the testing
requirements of magnet wire manufacturers, mo­tor designers and manufacturers, and manufac­turers of varnish and insulating materials.

The DTS-1600A will test up to five samples
(twisted pairs, motorettes or dielectric material)
simultaneously. The samples are installed in the
oven to facilitate testing at controlled and ele­vated temperatures. The test parameters are con­trolled and monitored through the control com­puter. Each channel can be individually enabled
or disabled, and programmed for current trip
threshold and voltage rise and fall time. The pulse
frequency, pulse width, amplitude (voltage) and
oven temperature are shared by all five channels.

The system can simultaneously pulse five capaci­tive samples of 50pF (a typical twisted pair) per

sample or three samples of 350pF each (a typical
motorette) at 20KHz frequency at ±1600V (3200V
peak-to-peak) in bipolar mode. (Higher capaci­tance loads can be driven at derated voltage and/
or frequency.) It can also drive an inductive load,
such as a motor stator, of 3mH at up to 3.5µs
pulse width and 1600V (typical oper a tin g par ame­ters) in unipolar mode. Typical output wave forms
are shown in Figures 1, 2 and 3.

When a sample under test fails (the charging cur­rent exceeds the current threshold, indicating the
sample has shorted or arced), the channel is dis­abled, and the failure information is logged to a
text file and displayed on the Graphical User In­terface (GUI) monitor. In addition to the parame­ters displayed and controlled through the GUI dis­play, each channel has current and voltage moni­tor outputs that can be monitored using an oscil­loscope or digitizer for real-time data acquisition
of the voltage and current profiles for each sam­ple during operation.

The DTS-1600A is controlled by its control com­puter and GUI, which provides the interface be-

ment in which time-to-failure is repeatable within
statistically allowable differences. For all practical
purposes, inverters do not offer this capability.

In addition, the DTS-1600A offers other advan­tages over testing using an inverter. These ad­vantages include:

• Capable of testing up to 5 samples simultane­ously.

• User-controlled, variab le vo ltag e, curr ent trip­point, pulse width, frequency, duty cycle, volt­age rise and fall time and sample tempera­ture.

• Computer control and logging of the test pa­rameters and failure data.

The DTS-1600A was developed in collaboration
with the U.S. Electrical Motors Division of Emer­son Electric, utilizing a patented test technique
developed by USEM

(1)

.

(1) Licensed under US Patent
#5,648,725 and Copyright of the Em­erson Electric Company, 1996

Figure 1

Typical rise time (~31ns) on fastest rise time setting, driving

a twisted pair (~50pF), ±1600V

Figure 2

Typical current (top trace) and voltage (bottom trace) wave-

forms, driving a twisted pair (~50pF), ±1600V

Figure 3

Typical voltage waveform (top trace) at 20KHz repetition

rate (bottom trace), driving a twisted pair (~50pF), ±1600V