9440300990 Rev J
97
DECS-250
Power System Stabilizer
generator voltage exceeds the terminal voltage setpoint
. The terminal voltage limiter is enabled and
disabled by software switch SSW 8
RR
. The limit setpoint is normally selected such that the limiter will
eliminate any contribution from the PSS before the timed overvoltage or volts per hertz protection
operates.
The limiter reduces the stabilizer’s upper limit, V
PSS_ULMT
, at a fixed rate until zero is reached or overvoltage
is no longer present. The limiter does not reduce the AVR reference below its normal level; it will not
interfere with system voltage control during disturbance conditions. The error signal (terminal voltage
minus the limit start point) is processed through a conventional low-pass filter to reduce the effect of
measurement noise. The low-pass filter is controlled by a time constant
SS
.
Figure 94. PSS Configuration Settings
Figure 95. PSS Control Settings
Summary of Contents for DECS-250
Page 2: ......
Page 6: ...iv 9440300990 Rev J Revision History DECS 250 ...
Page 16: ...xiv 9440300990 Rev J Contents DECS 250 ...
Page 20: ...4 9440300990 Rev J Introduction DECS 250 ...
Page 28: ...12 9440300990 Rev J Power Stage DECS 250 ...
Page 32: ...16 9440300990 Rev J Voltage and Current Sensing DECS 250 ...
Page 40: ...24 9440300990 Rev J Synchronizer DECS 250 ...
Page 52: ...36 9440300990 Rev J Auxiliary Control DECS 250 ...
Page 56: ...40 9440300990 Rev J Contact Inputs and Outputs DECS 250 ...
Page 84: ...68 9440300990 Rev J Limiters DECS 250 ...
Page 114: ...98 9440300990 Rev J Power System Stabilizer DECS 250 Figure 96 PSS Parameter Settings ...
Page 124: ...108 9440300990 Rev J Stability Tuning DECS 250 ...
Page 126: ...110 9440300990 Rev J Mounting DECS 250 Figure 103 Overall and Projection Mounting Dimensions ...
Page 127: ...9440300990 Rev J 111 DECS 250 Mounting Figure 104 DECS 250 Escutcheon Plate Dimensions ...
Page 198: ...182 9440300990 Rev J Timekeeping DECS 250 ...
Page 210: ...194 9440300990 Rev J CAN Communication DECS 250 ...
Page 304: ...288 9440300990 Rev J Maintenance DECS 250 ...
Page 316: ...300 9440300990 Rev J Specifications DECS 250 ...
Page 334: ...318 9440300990 Rev J Analog Expansion Module DECS 250 ...
Page 351: ......