Keysight RP7970 Serie Manuel D'utilisation page 108

4 Using the Regenerative Power System
PROT. Once the protection condition is corrected, clearing protection on the primary clears protection
on all units (see Clearing Protection).
If a secondary unit goes into protection, the primary and the secondary unit on which the protection
event occurred indicate the type of protection event. All other secondary units indicate PROT. Once the
protection condition is corrected, clearing protection on the primary clears protection on all units.
When using the Fault or Inhibit functions on the rear panel digital connector, connect the Fault/Inhibit
pins only on the primary unit. You do not need to connect the Fault/Inhibit pins of the secondary units.
Primary/Secondary Power Rating Considerations
Connect no more than twenty units of identical input and output voltage ratings.
The following special considerations apply when paralleling units with unequal power ratings.
While it is possible to parallel 20 kW and 30 kW units, the paralleling system operates on output
current - not output power. The output current is divided between the Primary and Secondary units in
proportion to the maximum output current capability of each unit. Some 30 kW models have different
auto-ranging characteristics than their 20 kW counterparts. When operating in a parallel configuration
these units (either the 20 kW or the 30 kW units) will reach their maximum output current limits before
achieving their maximum power limit. If the maximum output current limit is exceeded, the over-power
protection (OP+ or OP-) will trip.
If necessary, the full power output may be achieved by disabling the Primary/Secondary groups and
operating the units separately. Set the larger unit for CV operation and the smaller one for CC to
provide additional current. Units of different maximum voltages must never be paralleled.
Power Limitation when paralleling 2 kV, 20 kW units with 2 kV, 30 kW units
The following graph illustrates the Power Limitation when paralleling one 2 kV, 20 kW unit with one 2
kV, 30 kW unit.
When using a parallel configuration to current-share among mixed 2 kV models, the 20 kW units can
generate their full output power, but the 30 kW units are limited to 20 kW. This is shown by the green
portion of the graph, which illustrates that 10 kW are unavailable. Therefore, a power limitation of 40
kW applies to this parallel configuration.
108 Keysight RP7970 & RP7980 Series Operating and Service Guide