Basler Electric BE2000E - Manual (Page 25)

9287500995 Rev B 17
reduction of generator output voltage. A leading power factor generator load (capacitive) results in an
increase of generator output voltage. Droop is adjustable up to 10 percent with rated, nominal B-phase
line current (5 amperes applied through terminals CT1 and CT2) and 0.8 power factor. The droop feature
is enabled and disabled through the Parallel Generator Compensation contact input circuit (terminals 52L
and 52M). The 52J/K input must also be closed to disable droop.
Underfrequency
Generator Underfrequency
When generator frequency drops below the selected knee frequency setpoint, the voltage setpoint is
automatically adjusted by the BE2000E so that generator voltage follows the selected PU (per unit) V/Hz
curve. When operating on the selected PU V/Hz curve, the Underfrequency Active indicator flashes on
the front panel and in BESTCOMS
™-BE2000E software. The knee frequency is adjustable from 40 to 65
hertz and the PU V/Hz curve may be set to a slope from 1 to 3 in increments of 0.01 through the Windows
communication software. The default is 59 Hz and a slope of 1.
Engine Unloading
The engine unloading feature modifies the underfrequency curve. This feature becomes active when the
generator frequency decreases a programmable amount (Unloading Activation - Frequency) below the
knee frequency setpoint, and when the speed change rate is greater than the Unloading Activation - Rate.
The amount of droop while engine unloading is active is adjusted by the Unloading Droop - Percentage
(%) setting. The amount of time engine unloading is active is set by Unloading Droop - Time (sec.).
Engine unloading adjustments are made through BESTCOMS-BE2000E software.
Unloading Activation - Frequency (Hz) is entered as a value below the underfrequency corner where the
engine unloading feature may be activated. A frequency value of 0.9 to 9.0 Hz can be entered in 0.1 Hz
increments. The default value is 0.9 Hz.
Unloading Activation - Rate (Hz/25 ms) of 0 to 25.5 Hz per 25 ms can be entered in 0.1 Hz per 25 ms
increments. The engine unloading feature is activated when the frequency rate of change exceeds the
setting of this field. The default value is 0.1.
Unloading Droop - Percentage (%) field defines the percent drop in generator output voltage for each 1.5
percent decrease in generator frequency when operating in the Engine Unloading mode. The Unloading
Droop Percentage is adjustable from 1 to 20 percent in 1 percent steps. The default value is 10 percent.
Unloading Droop - Time (sec) value defines the length of time that the Engine Unloading mode may be
active before control is passed to the normal Underfrequency mode of operation. Droop time is adjustable
from 1 to 5 seconds in 1 second increments. The default value is 1 second.
Protection
The BE2000E has the six protective functions listed below:
•
Overexcitation shutdown
•
Generator overvoltage shutdown
•
BE2000E overtemperature shutdown
•
Loss of generator sensing shutdown
•
Overexcitation limiting
•
Crowbar shutdown
Each function, except Crowbar Shutdown, has a corresponding front panel indicator that lights when the
function is active. An active function (except Crowbar Shutdown) is also annunciated through the
Windows communication software.
Overexcitation Shutdown (Field Voltage)
This function is enabled or disabled through BESTCOMS-BE2000E software. When enabled, if field
voltage exceeds the setpoint (80 Vdc default), the Overexcitation Shutdown indicator flashes on the front
panel and in the Windows communication software, the relay output closes after 15 seconds and the
BE2000E Functional Description