Pre-Charge Using Dedicated I/O; Type 4 Pre-Charge (Resonant-Open Transfer-Capacitors Only) - Siemens SINAMICS PERFECT HARMONY GH180 Function Manual

Advanced Operating Functions

8.19 Pre-charge using Dedicated I/O

8.19.3 Pre-charge using Dedicated I/O
The software in these pre-charge types use dedicated I/O for controlling all contactors. Type 5
and 6 pre-charge read inputs and control outputs directly with no intervention from the SOP. The
only exception is the StartCellPrecharge_O flag to start pre-charge once the drive is ready
to pre-charge (DriveReadyToPrecharge_I is true).
Note
Water-cooled 750 V AP type cells must use type 5 open or type 6 closed pre-charge.
Other drive types may use type 5 open or type 6 closed pre-charge if hardware is in place.
Note
Air-cooled drives used for floating platforms may use type 6 (closed) pre-charge only. Pre-charge
for these cell types is for limiting transformer in-rush only; and, this is achieved through type 6
(closed) pre-charge.
See also
Type 5 (Open) Pre-charge (Page 276)
Type 5 (Open) Pre-charge (Page 276)
Type 6 (Closed) Pre-charge (Page 281)
Preconditions for Pre-charge Types 5 and 6 (Page 273)
8.19.4

Type 4 Pre-charge (resonant-open transfer-capacitors only)

Type 4 Pre-charge is open pre-charge mode for use with a drive within the 6SR4 family. The
introduction of the cell for this air-cooled drive brought the requirement to precharge the
capacitors with no pre-magnetization for the transformer.
Precharge was added to the new drive, with an open transference of power from the precharge
source to the line. The main purpose was to limit inrush current by limiting the charging current
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.
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NXGPro+ Control Manual
Operating Manual, A5E50491925A