12
1-800-735-6200
AC
Mains
120V
RMS
230
Vdc
DC
Output
of HAM
Boost Voltage
240
Vdc
Rectified Line
195
Vdc
Module
Enable
Off at
195
Vdc
25 ms
Power OK
Off at
230
Vdc
Vicor varies the output voltage of the VI-HAM
as a function of incoming AC line voltage
(see Fig. 4, patent applied for).
On a nominal
120Vac line the output voltage of the VI-HAM
is 260Vdc — well within the input operating
voltage range of standard Vicor converters.
As input line increases, so does the VI-HAM
output voltage; at 220Vac the delivered voltage
will be about 350V. For any given input line
voltage, the VI-HAM maintains enough
headroom between the output voltage and peak
input voltage to ensure high quality active
power factor correction without unnecessarily
sacrificing operating efficiency.
VI-HAM Protection Features
Overtemperature Shutdown
The VI-HAM incorporates overtemperature
shut-down, and is designed to shut down when
the temperature of the baseplate exceeds
90–100°C. It is not safe to run the VI-HAM
for extended periods above its maximum
operating temperature of 85°C.
Short Circuit Protection
The VI-HAM contains a short circuit shutdown
function. Operation of this function does not
clear the input fuse and the output will resume
normal operation after removal of the short.
A small period of time may be required to
allow for cooling of an internal PTC.
Overcurrent protection is provided by the
Vicor DC-DC converters.
Output Overvoltage Protection
The VI-HAM contains output overvoltage
protection. In the event the output voltage
exceeds approximately 420Vdc, the boost will
decrease to maintain 420Vdc on the output.
When the peak of the AC line exceeds 420V
(approximately 293Vac) the boost will have
been reduced to zero. Beyond this the protection
circuit will be enabled and the output voltage
will decrease.
Outputs
VI-200
DC-DC
Converter(s)
10 ms
400Vdc
350Vdc
300Vdc
250Vdc
200Vdc
80Vac
260Vdc
152Vac
85Vac
250Vac
46V
Boost
Output Voltage
as a Function
of Input Voltage
Figure 3 • Functional Timing Diagram
Active power factor correctors incorporate a
boost regulator which must operate over a range
of incoming AC line voltages. Conventionally,
the output voltage of the boost regulator is set
to a value greater than the maximum anticipated
peak value of the incoming AC line.
150Vdc
100Vdc
50Vdc
Vin x 2
Operating Region
75
50
100
125
150
Vac
275
250
300
296
264Vac
25
175
200
225
Figure 4 • Input Voltage vs. Output Voltage
Pin Function Description
• L1 and L2/N (VI-HAM):
These pins are to be connected to the AC mains
output of a suitable EMI/RFI filter (Vicor
P/N 07818 or equivalent). Do not connect an
X capacitor across these pins as power factor
correction will be slightly degraded.
• +IN, –IN (VI-HAMD, VI-BAMD):
These pins are connected to the output of the external
bridge rectifier.
• Gate Input (VI-HAM):
This pin disables the boost converter only. Rectified
line current may still be present on the output.
This pin
does not provide the same function as the gate input
pin of VI-200/VI-J00 modules.
The user should not
make any connection to this pin.
• Gate Input (VI-HAMD):
This pin serves as a rectified AC following pin for
power factor correction synchronization to line. This
connection must be made through the synchronization
diodes between the line filter and bridge rectifier
(see Fig. 10).
• Gate Input (VI-BAMD):
The Gate Input pin is an interface pin to the Gate Out
pin of a VI-HAM, VI-HAMD or VI-BAMD
depending on configuration. The user should not make
any other connection to this pin.
• Gate Output:
The Gate Output pin is an interface pin to BAMDs;
the user should not make any other connection to
this pin.
• +Output and -Output and Holdup Capacitor:
These outputs should be connected to the respective
inputs of Vicor DC-DC converters. In addition, an
external holdup capacitor of 1000 µF with a minimum
voltage rating of 450Vdc, is required across the
output for 16 ms ride through time at 600W (500 µF
for 300W, etc). Do not exceed 3000 µF of total
output capacitance. Lower values of capacitance may
be used for reduced holdup requirements, but not less
than 330 µF. Lower capacitance values may degrade
power factor specifications.
• Auxiliary Supply (A/S):
The VI-HAM and VI-BAMD contain an internal low
voltage output (A/S) that may be used to power
primary side logic. This output is 19-23Vdc,
referenced to -OUT, at 3 mA max. Do not overload or
short this output as the VI-HAM will fail. A typical
use for A/S is to power an optical coupler that isolates
the Power OK signal.
This provides sufficient time for the converters to turn
on and their outputs to stabilize prior to P/OK being
asserted. When the AC mains is removed and the
output of the VI-HAM drops below 230V, P/OK goes
to an open circuit state. When the output voltage drops
below 195V the converters are disabled via Module
Enable. P/OK will provide power fail warning at least
1 ms prior to converter shutdown.
D
LOGIC
G
S
P/OK
-OUT
Figure 6 • Power OK (P/OK)
+
19 - 23V
–
A/S
≤
3mA
-OUT
"Power OK" Status
Low = OK
+ OUT
P/OK
E/O
A/S
– OUT
18 kΩ, 1/4W
Figure 5 • Auxiliary Supply (A/S)
• Power OK (P/OK)
P/OK is a monitor signal that indicates the status of
the AC mains and the DC output voltage of the VI-HAM.
P/OK, during normal operation, is an active low (see
Fig. 6).
In the event AC mains or DC output fails, this
pin goes to an open circuit state. P/OK is asserted
when the output bus voltage is within normal operating
range and 20-25 ms after DC-DC converters are
enabled by the Module Enable output of the VI-HAM.
• Module Enable (E/O)
The Module Enable output is used to disable the
DC-DC converters until there is sufficient energy in
the holdup capacitor (240V) to support normal
operation, while limiting inrush current. Module
Enable must be connected to the Gate Input of all
driver DC-DC converters. It is not necessary to
connect this pin to boosters as they are controlled by
their respective driver. If the AC mains fail, Module
Enable goes low when the DC output of the VI-HAM
drops below 195V. Failure to connect Module Enable
may result in the output of the VI-HAM latching low
during turn-on.
E/O
D
LOGIC
G
S
-OUT
Figure 7 • Enable/Output (E/O)
Vicor Corp.
Tel: 800-735-6200, 978-470-2900 Fax: 978-475-6715
HAM, Harmonic Attenuator Module
Rev. 1.1
Page 2 of 6
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