Voltage dips, also called sags, are brief reductions in AC
mains voltage, typically between half a cycle to a few seconds.
The best-known sources of voltage dips and interruptions are
listed below:
The starting of a large load such as a motor or resistive
heater.
Loose or defective wiring such as insufficiently tightened
box screws on mains conductors leading to the increase of
your system impedance, thus, making itself vulnerable to
the effect of current increase.
Faults or short circuits draw excessive currents until the
protective devices such as a fuse or circuit breaker operates.
Faults on distant circuit typically which can be automatically
switched and removed by reclosers. This type of event is
sometimes a series of voltage dips caused by continuous
operation of reclosers.
Loads that have continuously varying power levels cause
voltage variations rather than an abrupt change.
In any case, these voltage changes can degrade the
performance of electronic equipment in many different
ways: digital circuit upset, data-loss or distortion and so
on. Therefore, immunity testing for these types of events
should be performed to ensure your product's safe and
reliable operation.
In fact, in the scheme of international compliance, the
IEC 61000-4-11 compliance voltage dip test is a must
for all products having a rated input current not
exceeding 16A per phase.
Clearly from the above, voltage dips, interruptions, and
variations are everywhere and unavoidable.
Voltage dips and short interruptions are not always abrupt
because of the reaction time of rotating machines and
protection elements- the rotating machines will operate as
generators sending power into the network. Some equipment,
typically containing a power-fail detection circuit, is more
vulnerable to gradual variations than to abrupt change.
The NoiseKen VDS-2002 Voltage Dip and Up Simulator,
uncompromising on and fully compliant with all the test
generator requirements in the standard including fast
rise and fall times, peak inrush current drive capability,
overshoot/undershoot and others, fulfills accurate
testing needs.
VDS-2002 Voltage Dip and Up Simulator
FEATURES
Fully compliant with all the test generator requirements of IEC standard
One unit solution for dip, swell, interruption, and variation tests up to 16A 290V single phase AC
Interruption test up to 16A 125V DC*
Two motor-driven transformers approach enables switching between any voltages*
Preset IEC test levels 0%/40%/70% additional 120%
Two modes for 0% (interruption) test: open & short*
Optional Windows Application Software available to more extensively control the unit
Accurate waveforms
* Optional software required
CONTROL PANEL
EUT OUTPUT:
receptacles (Multi-type) +Terminal Blocks for AC/DC.
TEST LEVEL:
selects a test level among 0, 40, 70 and 120%.
DIP CYCLES:
selects the duration of a dip among 0.5, 1, 5, 10, 25 and
50 cycles.
DIP PHASE:
selects the phase angle at which a dip starts among 0,
45, 90, 135, 180, 225, 270 and 315 degrees.
INTERVAL CYCLES:
selects the time interval between each dip among 1, 3,
5, 10, 30, 50, 100, 300, 500 cycles and 10s.
REPEAT COUNT:
selects the number of dips among 1, 3, 5, 10, 30, 50,
100 and infinite.
MEMORY NUMBER:
used to save or call up the selected test setting among
preset 5 settings
LINE: turns on and off power to the EUT
SW1:
for output verification, the unit outputs the normal
voltage adjusted by the slide transformer 1.
SW2:
for output verification, the unit outputs the dip/swell
voltages adjusted by the slider transformer 2.
START: starts the test.
STOP: stops the test.