Parallel and Series Connec�on

PST22 Rev. 01

Page 4 of 11

www.powersystemtechnology.com

Any output can be connected in series with any other output from the

same converter or from a separate converter, an external diode across

each output may be required.The maximum output current of a serial-

connected outputs is limited by the output with the lowest current

limit.Output voltages above 48V (SELV - Safety Extra Low Voltage)

require addi�onal safety measures in order to comply with interna�o-

nal safety requirements.

Parrallel opera�on is very simple . When 2 outputs will be connected

together , they will automa�cally current share without current share

Redundant Systems Opera�on

When systems require a very high level of reliability and should work

normally in the event of a failure, N+1 redundancy is implemented

where N is the number of converter to support power requirement. An

example of a redundant system using 3 converters is shown Fig1.If one

converter fail, the remaining ones s�ll delivers the power to the loads.

The ‘paralleling’ ac�ve circuit designed on every output of the PST22

replace the conven�onnal diodes by MOSFET with very low RdsON thus

divided by 10 the power losses.

Hold-up �me

The converters provide low hold-up �me. If a hold-up �me is required

(some railways applica�ons for example) , use external input capacitors

of adequat size.

Formula for addi�onal external input capacitor : C =2*Pout*th*100/

(V²-Vi²)/n

whereas :

C

= external input capacitance [mF]

n

= efficiency [%]

= hold-up �me [ms]

= minimum input voltage

Hot Swap

The low input inrush current allows the unit to be hot

swapped.Nevertheless care must be taken with senses lines and we

recommend to consult our technical support before opera�ng in the

mode.

Output Current Limita�on

All outputs are con�nously protected against short-circuit by a constant

current limita�on.(no foldback)

Thermal Considera�ons

When a converter is mounted in free air, in convec�on cooling, and is

opera�ng at its nominal output power at the max. ambiant temperatu-

re, the temperature measured on the heatsink should not exeed 100°C.

The dera�ng curves show the max power available from the converter

for the 4TE and 8TE versions versus ambiant temperature.

Thermal protec�on

A temperature protec�on is integrated in each Vicor modules, disabling

output when heatsink temperature exceed 105°C . the converter auto-

ma�cally restart, when the temperature drops below this limit.

Feuille3

PST22 8TE Output power vs Ambiant temp.

25

50

75

100

125

150

175

200

225

250

275

300

325

350

375

400

-20 -10 0°C 10°C 20°C 30°C 40°C 50°C 60°C 70°C 80°C 85°C

T°C

Free air

1m/s

Page 1

PST22 4TE Output power vs ambiant temp.

25

50

75

100

125

150

175

200

225

-20

-10

0°C 10°C 20°C 30°C 40°C 50°C 60°C 70°C 80°C 85°C

T°C

Free air

1m/s