Keysight Technologies RP7900 Series, Operating And Service Manual

Page: 116 / 318

Units of equivalent current ratings will share current equally. Units of dissimilar current ratings will
share current according the ratio of their current rating. For example, a unit rated at 40 A and a unit
rated at 20 A will share their output current in a 2-to-1 ratio.
In Independent Parallel operation only, the front panel status displays a "P", indicating that current
sharing is enabled and the sharing relay has closed to connect the unit to the sharing bus. When the
output is disabled, the sharing relay opens and disconnects the unit from the sharing bus.
Front Panel Menu Reference SCPI Command
Select Output\Advanced\CurrSharing
Check Enable current sharing to enable.
To enable current sharing:
CURR:SHAR ON
Current Sharing Operation
In voltage priority mode:
l
Program the initial output voltage setting of each paralleled unit to the same value.
l
Set the current limit of each unit according to the following equations. This lets all units share cur-
rent until the
total current limit point is reached, which is the sum of the individual current limits.
For each 5 kW unit: I
CL_5kW
=I
CL_TOTAL
/ (N
T
+N
10kW
)*
For each 10 kW unit: I
CL_10kW
=2(I
CL_TOTAL
) /( N
T
+N
10kW
)
where:
I
CL_5kW
is the current limit setting of the 5 kW unit
I
CL_10kW
is the current limit setting of the 10 kW unit
I
CL_TOTAL
is the sum total of all individual current limits
NT is the total number of paralleled units of any rating
N10kW is the total number of paralleled 10 kW units
*If there are no 10 kW units used, then N
10kW
= 0.
Note that in a mixed power configuration, you must set the current limit of the 10 kW units to twice the
value of the 5 kW units. This is because in a mixed power configuration, each 10 kW unit will contribute
twice as much current as each 5 kW unit.
When the current limit setting of any paralleled unit is reached, the output current of that unit will limit
at its specified setting.
In current priority mode:
l
Set the voltage limit of each paralleled unit to the same value.
l
Program the current setting of each paralleled unit according to the equations above if current
sharing is desired. The total output current will be the sum of all the individual current settings.
Note that in current priority mode, the sharing configuration will balance the currents only if all of the
units are operating in voltage limit mode, with the VL+ status annunciator on.
4 Using the Regenerative Power System
116 Keysight RP7900 Series Operating and Service Guide