Keysight RP7970 Serie Manuel D'utilisation page 107

Reduce the slew rates to mitigate imperfect voltage programming synchronization. By default, the
slew rates are set to their maximum values.
In current priority mode, set the output current of the primary unit to the desired
value. Set the voltage limit to a higher value than the expected operating voltage of
the unit.
Operation at Maximum Current
Due to individual circuit tolerances between the paralleled units in a primary/secondary configuration,
the current contributed by each unit may differ slightly from the ideal amount, which assumes that all
units share current equally. When operating at the maximum current rating of the paralleled group,
these individual circuit tolerances could cause one or more of the units to depart from CV operation
and enter into ± current limit. The maximum current rating of the group will still be available, but the
dynamic transient response may change due to the transition of one of the units into current limit.
If strict CV operation is required under all operating conditions, especially at the maximum current
rating of the paralleled group, it is recommended to set the current limit to the maximum
programmable value on the primary unit. If this is not sufficient, reduce the total requested load
current, or consider adding an extra unit to provide additional headroom for the group to maintain CV
operation under maximum load conditions.
Current Level Triggers
Current level triggers (see TRIGger:ACQuire:CURRent) are available in primary/secondary mode but
may have performance limitations. The measured current on the primary unit generates the
measurement trigger. Since current sharing between units may be temporarily degraded during fast
load current changes, the trigger timing could be affected. Therefore, this feature must be
characterized on a user's configuration to determine if the performance is sufficient. These limitations
do not apply when the output current is stable or the current change is relatively slow
Primary/Secondary Communication
While connected, the primary unit periodically polls the secondary units for status. If communication
with any secondary fails, for example if a secondary unit is turned on or off, the primary and remaining
secondary units go into primary/secondary protection (PSP). When the remaining secondary units
detect that the primary has disconnected, they also go into PSP. Additionally, a current-sharing fault
(CSF) will likely occur if the
Secondary units use the periodic primary status poll as a timer to trip PSP. If the secondary does not
receive a status poll every 10 seconds or less, it goes into PSP.
Secondary units may go into PSP 10 seconds after power-on. Once these units are discovered, the
primary unit will establish communication with the secondary units, thereby clearing the PSP.
Primary/Secondary Protection
If the primary unit goes into protection, it sends a protection command to the secondary units. The
primary unit indicates the type of protection event that has occurred. The secondary units indicate
Keysight RP7970 & RP7980 Series Operating and Service Guide
termination switches are not set correctly.
4 Using the Regenerative Power System
107