Vicor VI-J00 Family DC-DC Converters and Configurable Power Supplies - Manual (Page 36)

Design Guide & Applications Manual
For VI-200 and VI-J00 Family DC-DC Converters and Configurable Power Supplies
VI-200 and VI-J00 Family Design Guide Rev 3.5 vicorpower.com
Page 35 of 98
Apps. Eng. 800 927.9474 800 735.6200
CHOOSING APPROPRIATE VALUES FOR AIM MODULES
Sample calculation:
Converter output power (P OM ) = 100 W
Line frequency = 60 Hz
Line range = 105 – 264 Vac
Efficiency = 82%
Desired hold-up time = 5 ms (minimum)
therefore:
P IM =
100 = 122 W
0.82
T5 – T3 = 5 ms + 8.3 ms = 13.3 ms
(minimum hold-up time plus half cycle)
Vp = 105 X 2 = 148 V
Vdo = 100 V
and:
C1 =
2 X 122 X 0.0133
148 2 – 100 2
C1 = 270 µF
where:
V P = The peak of the rectified AC line or 2 X Vac
in
.
For an input range of 85 – 264 Vac, this voltage
will vary from 120 – 373 V.
V
V
= The low point of the rectified AC line under
normal operating conditions. This “valley” voltage
is a function of C1, P
IM and line frequency. The
peak-to-peak ripple across C1 is V P – V V and
determines the ripple current in C1.
NOTE: It is important to verify the rms ripple
current in C1 with a current probe.
V do = Voltage at which the DC-DC converter(s) begin(s) to
drop out of regulation. This voltage is from the data
sheet of the appropriate module, which for the
VI-270 Family is 100 Vdc. Under normal operating
conditions, V
V
must exceed V
do
.
T1 = The peak of the rectified AC line or the point at
which C1 is fully charged. For an input range of
85 – 264 Vac, this voltage will vary from 120 – 373 V.
T2 = The low point of the rectified AC line under
normal operating conditions and the point at
which C1 is about to be “recharged”. This is the
point of lowest energy in C1.
T4 = The low point of the rectified AC line; the point
of lowest energy in C1; the point at which if the
AC line fails, hold-up time is shortest, i.e., “worst
case”.
T5 = The time at which the converter(s) drop out of
regulation.
T5 – T4 = Minimum hold-up time. Actual hold-up time
may vary up to a maximum of T5 – T3.
(T3 – T1) X 2 = One line cycle.
The following values are calculated in a similar manner.
C1 values as a function of line voltage, frequency and
delivered power, for use with the “7” input designator
DC-DC converters (AIM input of 90–264 Vac) or “5” input
designator (AIM input of 90–132 Vac) DC-DC converters.
NOTE: With “7” input DC-DC converters operated
from the AIM input range of 90 – 264 Vac, 400 V
capacitors must be used (Vicor Part #30240). With
“5” input DC-DC converters used over the AIM input
range of 90 – 132 Vac, 200 V capacitors may be used
(Vicor Part #30769).
C1 values as a function of line voltage, frequency and
delivered power, for use with the “6” input designator
DC-DC converters (AIM input of 180 – 264 Vac).
NOTE: With “6” input DC-DC converters operated
from the AIM input range of 180 – 264 Vac,
400 V capacitors must be used (Vicor Part #30240).
√
√
50 W 270 µF 135 µF 300 µF 150 µF
75 W 400 µF 200 µF 440 µF 230 µF
100 W 525 µF 270 µF 600 µF 300 µF
150 W 800 µF 400 µF 890 µF 455 µF
200 W 1,000 µF 540 µF 1,180 µF 600 µF
Table 12–1 — Hold-up capacitor values for use with VI-270 / VI-J70
and the VI-250 / VI-J50 DC-DC converters.
Module(s) 60 Hz 50 Hz
Delivered Power 90 Vac 105 Vac 90 Vac 105 Vac
Table 12–1 — Hold-up capacitor values for use with VI-260 / VI-J60
DC-DC converters.
12. AC Input Module (AIM / MI-AIM)
50 W 66 µF 34 µF 74 µF 38 µF
75 W 100 µF 50 µF 110 µF 60 µF
100 W 130 µF 67 µF 150 µF 75 µF
150 W 200 µF 100 µF 220 µF 115 µF
200 W 262 µF 135 µF 300 µF 150 µF
Module(s) 60 Hz 50 Hz
Delivered Power 180 Vac 210 Vac 180 Vac 210 Vac