PT5040 Operation Manual Chapter 7 User guide
BDV test
Determine an impulse voltage appropriate to test.
The applied voltage has little effect on the turn-to-turn short test and the layer-to-layer short
test of coil, but the amplitude of the applied impulse voltage has a great impact on the
insulation test of coil. PT50xx solves the problem of how to set an appropriate voltage.
When it is required to determine an appropriate voltage for a kind of new product or for trial
test, except the industrial specified voltage, PT50xx can find out the appropriate test voltage
by switching on the BDV test function.
Enter the setup page and turn on BDV test. After setting start voltage, end voltage and step
voltage, turn on the corona comparison and return to the measurement display page. Press
START to start the test on DUT from the start voltage and then raise the voltage by step
voltage. By observing the corona discharge (corona transition value), the voltage can be
determined. 70~80% of the voltage is appropriate for test voltage.
Technology application
Test
objects
1.
Turn-to-turn and layer-to-layer short
Turn-to-turn short refers to the short caused by the insulation damage between turns.
Layer-to-layer short occurs in the coil consisting of multiple layers. There are two
kinds of short: direct short and pull arc short, both of which are shown as more
dissipation.
2.
Bad coil
The different number of coils will cause the variation of inductance, which is reflected
as the change of oscillation period.
3.
Corona discharge
Due to the use of impulse high voltage, if the insulations between the coil and layer
and terminal are not strong enough, operator can observe the discharge and the corona
discharge phenomenons. The corona discharge that can be captured by the impulse
winding tester has weak energy. Instead of influencing the attenuation oscillation wave,
it is only displayed as discrete jumping points around the waveform of high potential.
4.
Material of magnetic core
Whether a magnet is used in the coil as the magnetic core or the magnet is poor, above
conditions of the magnet will influence the inductance and the dissipation. Likewise, if
air gas is designed in the magnetic core, the size of which will also have an impact on
the inductance and the dissipation. Effects mentioned above will show as changes of
the attenuating vibration period and the attenuation degree.
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