Siemens SINAMICS DCM Manual page 585

Descriptions of functions
10.28 Field reversal
10.28.2 Braking using field reversal
The function "Braking using field reversal" is controlled using the signal source set at
binector input p50581 and this has a button-type function.
Binector input = 1 (for ≥30 ms) in operating state ≤o5 (line contactor closed) causes the drive
to brake to n < n
accelerate in the original direction of rotation after the braking command has been withdrawn
(binector input = 0) and acknowledging using "Stop" and "Switch-on".
Control sequence when specifying "Braking using field reversal":
1. Drive rotates with direction of rotation 1
2. Specify "Braking using field reversal" using log. 1 (for ≥30 ms) at the binector input
selected using p50581
3. The field is reversed.
Preconditions: Line contactor is closed (for operating state ≤o5) and the drive is already
braking anyway.
Braking is identified by the negative internal actual speed (whereby, this is obtained in the
negative field direction by reversing the real actual speed):
– Wait until armature current I
– Inhibit field firing pulses (r52268=0 also initiates this)
– Wait until I
– Wait time according to p50092[00] (0.0 to 10.0 s, factory setting 3.0 s)
– Open actual field contactor (r53195[0] = 0 or r53195[1] = 0)
– Wait time according to p50092[01] (0.0 to 10.0 s, factory setting 0.2 s)
– Control new field contactor (r53195[1] = 1 or r53195[0] = 1)
– Reverse the speed actual value (with the exception, for p50083 = 3 ... EMF as speed
– Wait time according to p50092[02] (0.0 to 10.0 s, factory setting 0.1 s)
– Enable field firing pulses
– Wait until I
– Wait time according to p50092[03] (0.0 to 10.0 s, factory setting 3.0 s)
– Enable armature firing pulses (operating state o1.4 can be exited)
4. Sequence when braking the drive:
– n
– Wait until n < n
– Wait until armature current I
– Wait until the braking command has been withdrawn using binector level = 0 (as long
586
. After this, the original field direction is selected. The motor can
min
in operating state ≥ o1.4)
(r52265) < I
field
actual value)
(r52265) > I
field
= 0 internally entered at the ramp-function generator input, the drive brakes
set
(p50370)
min
operating state o7.2)
as level = 1 is present, the drive is kept in operating state o7.2)
ac.maher.co.ir
= 0 , then armature pulse inhibit (the drive then remains
A
(p50394)
field min
(r52268)×p50398
field set
= 0 , then armature pulse inhibit (drive goes into
A
Operating Instructions, 02.2015, A5E34763375/RS-AA/001
SINAMICS DCM DC Converter