Siemens 7SJ82 Manual page 1221

Limiting Values for the Two-Winding Transformer
Parameter: Lower tap-position limit
•
Default setting (_:14011:102) Lower tap-position limit = 1
Parameter: Higher tap-position limit
•
Default setting (_:14011:103) Higher tap-position limit = 1
With the parameters Lower tap-position limit and Higher tap-position limit, you can restrict
the taps available in automatic operation. For example, using the parameter Higher tap-position
limit, changes to higher taps to excessive ratios that would result in overvoltages in the event of a sudden
loss of load are blocked.
Parameter: Vmin limiting
•
Default setting (_:14011:128) Vmin limiting = on
Parameter: Vmin threshold
•
Default setting (_:14011:129) Vmin threshold = 105.000 V
Parameter: Vmin time delay
•
Default setting (_:14011:130) Vmin time delay = 10 s
Parameter: Vmax limiting
•
Default setting (_:14011:131) Vmax limiting = on
Parameter: Vmax threshold
•
Default setting (_:14011:132) Vmax threshold = 115.000 V
Parameter: Vmax time delay
•
Default setting (_:14011:133) Vmax time delay = 10 s
The voltage limits are necessary only for special control situations. The overvoltage limit prevents a change to
a higher tap by the controller if the limiting value Vmax threshold is exceeded. The undervoltage limit
prevents a change to a lower tap by the controller if the voltage drops below the limiting value Vmin
threshold.
Limiting Values for Three-Winding Transformer and Grid Coupling Transformers
Parameter: Vmin threshold w1
•
Default setting (_:129) Vmin threshold w1 = 105.000 V
Parameter: Vmin threshold w2
•
Default setting (_:148) Vmin threshold w2 = 105.000 V
Parameter: Vmax threshold w1
•
Default setting (_:132) Vmax threshold w1 = 115.000 V
Parameter: Vmax threshold w2
•
Default setting (_:149) Vmax threshold w2 = 115.000 V
Blockings for the Two-Winding Transformer
Parameter: Blocking behavior
•
Default setting (_:14011:134) Blocking behavior = Auto-Manual
If the corresponding voltage limits are exceeded in either direction, the blockings prevent a change to a lower
or higher tap. On the one hand, this prevents excessive wear of the contacts of the tap changer and, on the
other hand, it prevents a system incident. With the parameter Blocking behavior, you set whether these
blockings are effective only in automatic operation or in both automatic and manual operation.
Parameter: V< Blocking
•
Default setting (_:14011:135) V< Blocking = on
Parameter: V< Threshold
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
Control Functions
8.9 Voltage Controller
1221