STMicroelectronics STEVAL-IHT008V1 User Manual page 24

Mains voltage dips and interruptions
during the line interrupt. When the voltage is reapplied, the peak current is only 30 A as the
DC voltage only decreased by 60 V during the absence of AC voltage.
For case b, as the interrupt lasts more than 30 ms, the T_ICL Triac is re-triggered when the
AC voltage is reapplied. To avoid an excessive inrush current caused by long interrupts,
the T_ICL Triac is controlled in a soft-start procedure like for any system startup. The DC
capacitor thus starts being recharged when the T_ICL gate current is applied while the AC
voltage is higher than the C voltage. In
interruption", this point occurs around 45 ms after the line voltage is reapplied. The peak
current is then only 10 A, which is only around two times the nominal current, comfortably
low enough to avoid any component damage.
Figure 16: "(a) Board operation during 1-cycle line interruption"
operation during 2-cycle line interruption"
2-cycle (b) line interruption.
Figure 16: (a) Board operation during 1-
Table 4: "Required dips and interruptions tests and STEVAL-IHT008V1 performance"
the different dips or interruption tests required for the different standards listed at the
beginning of this section. The test results of the STEVAL-IHT008V1 board are also given
for all tests.
These tests results only apply to the inrush current limitation function (thus T_ICL
Triac control).
Table 4: Required dips and interruptions tests and STEVAL-IHT008V1 performance
Standard
IEC
61000-6-1
IEC
24/37
cycle line interruption
Application Test type
residential,
Dips
commercial and
light-industrial
environments
Interruptions
Dips
industrial
DocID029048 Rev 1
Figure 17: "(b) Board operation during 2-cycle line
illustrate board operation during a 1-cycle (a) or
Figure 17: (b) Board operation during 2-
cycle line interruption
%
Number
residual
of cycles
voltage
0 0.5
0 1
1
70 25 /30
1
0 250 /300
0 1
and Figure 17: "(b) Board
Required STEVAL-
criteria by IHT008V1
standard result
B
B
2
C
2
C
B
UM2027
lists
A
A
A
A
A