Siemens sinamics dcp - Page 409

Operation
7.22 Connecting several SINAMICS DCPs in parallel
SINAMICS DCP
Operating Instructions, 09/2019, A5E34382853K
407
● Parallel interface operating modes
The parallel interface offers various slave operating modes.
These can be selected using p51800.
–
p51800 = 11: Slave (STW, I_SET, PULSEFREQ)
In this operating mode, the slave reads-in the switch-on commands ON/OFF1
(r0898.0) and operating enable (r0898.3) as well as the setpoint current (r55172) and
the switching frequency (r55325) of the master.
This means that when switching-on, the slave follows the master and also accepts its
setpoint.
–
p51800 = 21: Slave (STW, PULSEFREQ)
The slave reads-in the switch-on commands ON/OFF1 (r0898.0), operating enable
(r0898.3) and the switching frequency (r55325) of the master.
The slave itself calculates the current setpoint.
In operation, the slave follows the switching frequency of the master, e.g. for a
variable switching frequency (see Chapter "Switching frequency (Page 349)") or
overtemperature (see Chapter "Derating (Page 357)").
This means that closed-loop voltage control with droop can be implemented, where
the slave is switched-on together with the master; however, it uses its own voltage
controller.
–
p51800 = 22: Slave (STW)
The slave only reads-in the switch-on commands ON/OFF1 (r0898.0) and operating
enable (r0898.3) from the master. The slave must calculate the current setpoint and
the switching frequency based on the signals and operating conditions that are
available.
As a consequence, for example, a PV array can be operated where each DCP
operates its own dedicated part of the array; however, power is injected into the line
supply/grid via a common inverter.
The master switches on the DCP devices in synchronism; however, they can
independently respond to operating condition changes, such as cloudy conditions.
●
Configuration and commissioning
– Set a unique station address in the range 1... 15 (p51806) for each participant/node
(master and slaves).
– The bus termination (p51805) must be activated at the devices at the beginning and
end of the data bus of the parallel interface.
– Interconnect the switch-on commands of the master (r53310.2, r53310.3) to the slaves
(p0840 = r53310.2, p0852 = r53310.3).
The current setpoint and the pulse frequency of the master are automatically
connected depending on the setting of p51800.
– Activate the parallel interface; define the master and slave as well as the operating
mode (p51800).
– Adapt the remaining parameters to the system configuration (p51807, etc.).