ST STEVAL-ISF003V1, Руководство пользователя

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UM2076 Mains voltage dips and interruptions
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Table 5: Dip and interruption tests and STEVAL-ISF003V1 performance
Standard Application Test type
%
residual
voltage
Number of
cycles
Required
criteria by
standard
STEVAL-
ISF003V1
result
IEC 61000-6-1
Residential,
commercial and
light-industrial
environments
Dips
0 0.5 B A
0 1 B A
70 25
(1)
/30
(2)
C A
Interruptions 0 250
(1)
/300
(2)
C A
IEC 61000-2-1
industrial
environments
Dips
0 1 B A
40 10
(1)
/12
(2)
C B
70 25
(1)
/30
(2)
C A
Interruptions 0 250
(1)
/300
(2)
C B
EN 55024
information
technology
equipment
Dips
less than 5 0.5 B A
70 25 C A
Interruptions less than 5 250 C B
EN 55014-2
Appliances,
electric tools, etc.
Dips
0 0.5 C A
40 10 C B
70 50 C A
Notes:
(1)
50 Hz line frequency
(2)
60 Hz line frequency
The STEVAL-ISF003V1 board MCU firmware is programmed to comply with these different
tests thus:

If the line voltage remains higher than 70% of the reference voltage (measured at
board start-up), no change applies to the SCR (T1 and T2) sequence.

If the line voltage falls below 70% of the reference voltage during at least 1.5 cycles,
SCRs (T1 and T2) are switched off. The DC bus voltage is discharged by its load
current. When the line voltage is reapplied, the SCRs are controlled back in soft-start
to ensure recharging current limitation. Clearly, SCR restart only occurs if the HVDC
ON SPST switch (SW2) is kept at the ON position. Note that the 1.5 cycle duration to
detect voltage dip that lasts too long is given by the parameter
Nb_Peak_VAC_Dips
,
which is set to three by default (three times the measured low peak AC voltage). The
ratio of voltage decrease from which an undervoltage is taken into account is set by
the parameter
VAC_Variation_Dips
in the firmware (the default value is 0.3 for
30% maximum mains voltage reduction).
The same table also provides the test results of the STEVAL-ISF003V1 inrush-current-
limitation function (i.e., SCR control). Criteria A is ensured for all dips, even with a 0%
residual line voltage, shorter than 1 cycle. Criteria B is ensured for longer interruptions,
including 300 cycles or more. The STEVAL-ISF003V1 board performance therefore
comfortably exceeds international standard requirements.
The following figures illustrate board behavior at 230 V with a 1000 W DC resistive load, for
two different voltage dips with a 0% residual voltage applied over 20 ms (
Figure 19: "Board
operation during 1-cycle line interruption" ) and 40 ms ( Figure 20: "Board operation during
2-cycle line interruption" ).