Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 272

Advanced Operating Functions
8.17 Synchronous Transfer
for the capacitors, while not eliminating the inrush to the transformer. For this package, a
damping resistor was not used. For consistency, the M1 contactor operation is the same as used
in type 5 & 6 precharge. However, the other inputs and outputs are not consistent with Type 5
or Type 6 precharge and must be assigned from within the SOP. The only exception is the CIMV
output which will take the place of the "Trip MV" output of the air-cooled drive, and the TIMV of
the water cooled using NXGII control.
The timing to complete the precharge is 30 seconds, and 5 seconds is allowed to close M1. Both
are hard-coded. Precharge must go from start to complete in less than 30 seconds or a precharge
fault will be triggered.
Precharge will also control the precharge circuit breaker (PCB) – both in reading status and in
command control – but only through SOP flags – not dedicated I/O. The flag
"ClosePrechargeCB_I" is set true if no precharge faults or Input Protection (IP) faults exist. This
should be used to close the PCB. If a precharge fault is detected, the flag is cleared (set false) to
open the PCB. The hardware must support this in the control of the circuit breaker.
Cell diagnostics are not performed until precharge is complete (M1 closes and begins once the
Input voltage exceeds 60% of rated).
If all precharge conditions are met, the DriveReadyToPrecharge_I flag is true". Otherwise, the
DriveReadyToPrecharge_I flag is set false. Therefore this flag should be used as part of the
conditions to start pre-charge. Precharge cannot be initialized or started if this flag is not true.
Once precharge commences, the flag goes false and remains false until all conditions are again
met.
When all conditions are met, the pre-charge state machine advances from the initial state of
"PRECHARGE_FAULTED" through "INIT_PRECHARGE2", into the "PRECHARGE_READY" state. The
loss of the DriveReadyToPrecharge_I flag causes the state machine to cycle back to
"INIT_PRECHARGE2" until the drive is ready.
Fault and status messages will closely follow existing messages for type 5 and 6 except where
new or different.
The precharge circuit breaker is commanded to open under the following conditions during
precharge, resulting in precharge fault:
• Over-voltage (>115 %) occurs during pre-charge
• Under-Voltage Trip (PCVMRStatus_O)
• Input Protection Fault
• LFR Trip
• E-Stop (PB-4)
• M2 Contactor Open Status Failure
• Trip_CB2 is asserted (TripPrechargeCB2_O) through the SOP
The CB trip can only be controlled via the setting of an SOP flag (ClosePrechargeCB_I) to trip the
CB. To simplify, this flag will be used so that the desired action can be set to a single output point.
In addition to being triggered by an internal event, the setting of the SOP Input flag
TripPrechargeCB2_O, will also set the Output SOP flag ClosePrechargeCB_I.
Conditions to set the drive ready for precharge
270
NXGPro+ Control Manual
Operating Manual, A5E50491925A